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author heinrichsweikamp
date Wed, 24 Apr 2013 19:22:45 +0200
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1 // **************************************************************
2 // p2_deco.c
3 //
4 // Created on: 12.05.2009
5 // Author: chsw
6 //
7 // **************************************************************
8
9 //////////////////////////////////////////////////////////////////////////////
10 // OSTC - diving computer code
11 // Copyright (C) 2011 HeinrichsWeikamp GbR
12 //
13 // This program is free software: you can redistribute it and/or modify
14 // it under the terms of the GNU General Public License as published by
15 // the Free Software Foundation, either version 3 of the License, or
16 // (at your option) any later version.
17 //
18 // This program is distributed in the hope that it will be useful,
19 // but WITHOUT ANY WARRANTY; without even the implied warranty of
20 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 // GNU General Public License for more details.
22 //
23 // You should have received a copy of the GNU General Public License
24 // along with this program. If not, see <http://www.gnu.org/licenses/>.
25 //
26 //////////////////////////////////////////////////////////////////////////////
27
28 // *****************************
29 // ** I N T R O D U C T I O N **
30 // *****************************
31 //
32 // OSTC
33 //
34 // code:
35 // p2_deco_main_c_v101.c
36 // part2 of the OSTC code
37 // code with constant O2 partial pressure routines
38 // under construction !!
39 //
40 // summary:
41 // decompression routines
42 // for the OSTC experimental project
43 // written by Christian Weikamp
44 // last revision __________
45 // comments added _________
46 //
47 // additional files:
48 // p2_tables_v100.romdata (other files)
49 // 18f4685_ostc_v100.lkr (linker script)
50 //
51 // history:
52 // 01/03/08 v100: first release candidate
53 // 03/13/08 v101: start of programming ppO2 code
54 // 03/13/25 v101a: backup of interrim version with ppO2 calculation
55 // 03/13/25 v101: open circuit gas change during deco
56 // 03/13/25 v101: CNS_fraction calculation
57 // 03/13/26 v101: optimization of tissue calc routines
58 // 07/xx/08 v102a: debug of bottom time routine
59 // 09/xx/08 v102d: Gradient Factor Model implemenation
60 // 10/10/08 v104: renamed to build v103 for v118 stable
61 // 10/14/08 v104: integration of char_I_depth_last_deco for Gradient Model
62 // 03/31/09 v107: integration of FONT Incon24
63 // 05/23/10 v109: 5 gas changes & 1 min timer
64 // 07/13/10 v110: cns vault added
65 // 12/25/10 v110: split in three files (deco.c, main.c, definitions.h)
66 // 2011/01/20: [jDG] Create a common file included in ASM and C code.
67 // 2011/01/24: [jDG] Make ascenttime an short. No more overflow!
68 // 2011/01/25: [jDG] Fusion deco array for both models.
69 // 2011/01/25: [jDG] Use CF(54) to reverse deco order.
70 // 2011/02/11: [jDG] Reworked gradient-factor implementation.
71 // 2011/02/15: [jDG] Fixed inconsistencies introduced by gas switch delays.
72 // 2011/03/21: [jDG] Added gas consumption (CF56 & CF57) evaluation for OCR mode.
73 // 2011/04/15: [jDG] Store low_depth in 32bits (w/o rounding), for a better stability.
74 // 2011/04/25: [jDG] Added 1mn mode for CNS calculation, to allow it for decoplanning.
75 // 2011/04/27: [jDG] Fixed char_O_gradient_factor calculation when model uses gradient-factor.
76 // 2011/05/02: [jDG] Added "Future TTS" function (CF58).
77 // 2011/05/17: [jDG] Various cleanups.
78 // 2011/08/08: [jDG] Computes CNS during deco planning ascent.
79 // 2011/11/24: [jDG] Slightly faster and better NDL computation.
80 // 2011/12/17: [mH] Remove of the useless debug stuff
81 // 2012/02/24: [jDG] Remove missed stop bug.
82 // 2012/02/25: [jDG] Looking for a more stable LOW grad factor reference.
83 // 2012/09/10: [mH] Fill char_O_deco_time_for_log for logbook write
84 // 2012/10/05: [jDG] Better deco_gas_volumes accuracy (average depth, switch between stop).
85 // 2013/03/05: [jDG] Should vault low_depth too.
86 // 2013/03/05: [jDG] Wrobell remark: ascent_to_first_stop works better with finer steps (2sec).
87 //
88 // TODO:
89 //
90 // Literature:
91 // Bühlmann, Albert: Tauchmedizin; 4. Auflage [2002];
92 // Schr"oder, Kai & Reith, Steffen; 2000; S"attigungsvorg"ange beim Tauchen, das Modell ZH-L16, Funktionsweise von Tauchcomputern; http://www.achim-und-kai.de/kai/tausim/saett_faq
93 // Morrison, Stuart; 2000; DIY DECOMPRESSION; http://www.lizardland.co.uk/DIYDeco.html
94 // Balthasar, Steffen; Dekompressionstheorie I: Neo Haldane Modelle; http://www.txfreak.de/dekompressionstheorie_1.pdf
95 // Baker, Erik C.; Clearing Up The Confusion About "Deep Stops"
96 // Baker, Erik C.; Understanding M-values; http://www.txfreak.de/understanding_m-values.pdf
97 //
98 //
99
100 // *********************
101 // ** I N C L U D E S **
102 // *********************
103 #include <math.h>
104
105 // ***********************************************
106 // ** V A R I A B L E S D E F I N I T I O N S **
107 // ***********************************************
108
109 #include "p2_definitions.h"
110 #define TEST_MAIN
111 #include "shared_definitions.h"
112
113 // Water vapour partial pressure in the lumb.
114 #define ppWater 0.0627
115 #define METER_TO_BAR 0.09985
116 #define BAR_TO_METER 10.0150 // (1.0/METER_TO_BAR)
117
118 // Surface security factor
119 #define SURFACE_DESAT_FACTOR 0.7042
120
121 // *************************
122 // ** P R O T O T Y P E S **
123 // *************************
124
125 static void calc_hauptroutine(void);
126 static void calc_nullzeit(void);
127
128 static void calc_tissue(PARAMETER unsigned char period);
129 static void calc_limit(void);
130
131 static void clear_tissue(void);
132 static void calc_ascenttime(void);
133 static void update_startvalues(void);
134 static void clear_deco_table(void);
135 static unsigned char update_deco_table(void);
136
137 static void sim_tissue(PARAMETER unsigned char period);
138 static void sim_limit(PARAMETER float GF_current);
139 static void sim_extra_time(void);
140 static void calc_dive_interval(void);
141
142 static void calc_gradient_factor(void);
143 static void calc_wo_deco_step_1_min(void);
144
145 static void calc_hauptroutine_data_input(void);
146 static void calc_hauptroutine_update_tissues(void);
147 static void calc_hauptroutine_calc_deco(void);
148 static void sim_ascent_to_first_stop(void);
149
150 static unsigned char gas_switch_deepest(void);
151 static void gas_switch_set(void);
152
153 static unsigned char calc_nextdecodepth(void);
154
155 //---- Bank 5 parameters -----------------------------------------------------
156 #ifndef UNIX
157 # pragma udata bank5=0x500
158 #endif
159
160 static float GF_low;
161 static float GF_high;
162 static float GF_delta;
163 static float locked_GF_step; // GF_delta / low_depth
164
165 static unsigned char temp_depth_limit;
166 static unsigned char low_depth; // Depth of deepest stop
167
168 // Simulation context: used to predict ascent.
169 static unsigned char sim_lead_tissue_no; // Leading compatiment number.
170 static float sim_lead_tissue_limit; // Buhlmann tolerated pressure.
171
172 // Real context: what we are doing now.
173 static float calc_lead_tissue_limit; //
174
175 static unsigned char internal_deco_time[NUM_STOPS];
176 static unsigned char internal_deco_depth[NUM_STOPS];
177
178 static float cns_vault;
179 static float low_depth_vault;
180 static float pres_tissue_N2_vault[NUM_COMP];
181 static float pres_tissue_He_vault[NUM_COMP];
182
183 //---- Bank 6 parameters -----------------------------------------------------
184 #ifndef UNIX
185 # pragma udata bank6=0x600
186 #endif
187
188 static unsigned char ci;
189 static float pres_respiration;
190 static float pres_surface;
191 static float temp_deco;
192 static float ppN2;
193 static float ppHe;
194 static float temp_tissue;
195 static float N2_ratio; // Breathed gas nitrogen ratio.
196 static float He_ratio; // Breathed gas helium ratio.
197 static float var_N2_a; // Bühlmann a, for current N2 tissue.
198 static float var_N2_b; // Bühlmann b, for current N2 tissue.
199 static float var_He_a; // Bühlmann a, for current He tissue.
200 static float var_He_b; // Bühlmann b, for current He tissue.
201 static float var_N2_e; // Exposition, for current N2 tissue.
202 static float var_He_e; // Exposition, for current He tissue.
203 static float var_N2_ht; // Half-time for current N2 tissue.
204 static float var_He_ht; // Half-time for current N2 tissue.
205
206 static float pres_diluent; // new in v.101
207 static float const_ppO2; // new in v.101
208
209 static unsigned char sim_gas_last_depth; // Depth of last used gas, to detected a gas switch.
210 static unsigned char sim_gas_last_used; // Number of last used gas, to detected a gas switch.
211 static unsigned short sim_dive_mins; // Simulated dive time.
212 static float calc_N2_ratio; // Simulated (switched) nitrogen ratio.
213 static float calc_He_ratio; // Simulated (switched) helium ratio.
214 static float CNS_fraction; // new in v.101
215 static float float_saturation_multiplier; // new in v.101
216 static float float_desaturation_multiplier; // new in v.101
217 static float float_deco_distance; // new in v.101
218 //static char flag_in_divemode; // new in v.108
219
220 static unsigned char deco_gas_change[NUM_GAS]; // new in v.109
221
222 //---- Bank 7 parameters -----------------------------------------------------
223 #ifndef UNIX
224 # pragma udata bank7=0x700
225 #endif
226
227 float pres_tissue_N2[NUM_COMP];
228 float pres_tissue_He[NUM_COMP];
229 float sim_pres_tissue_N2[NUM_COMP]; // 16 floats = 64 bytes.
230 float sim_pres_tissue_He[NUM_COMP]; // 16 floats = 64 bytes.
231
232 //---- Bank 8 parameters -----------------------------------------------------
233 #ifndef UNIX
234 # pragma udata overlay bank8=0x800
235 static char md_pi_subst[256];
236 # define C_STACK md_pi_subst // Overlay C-code data stack here, too.
237 #endif
238
239 // Back to bank6 for further tmp data
240 #ifndef UNIX
241 # pragma udata bank6
242 #endif
243
244 //////////////////////////////////////////////////////////////////////////////
245 //////////////////////////////////////////////////////////////////////////////
246 ///////////////////////////// THE LOOKUP TABLES //////////////////////////////
247 //////////////////////////////////////////////////////////////////////////////
248 //////////////////////////////////////////////////////////////////////////////
249 //
250 // End of PROM code is 17F00, So push tables on PROM top...
251 //
252 #ifndef UNIX
253 # pragma romdata buhlmann_tables = 0x1DD00 // Needs to be in UPPER bank.
254 #endif
255
256 #include "p2_tables.romdata" // new table for deco_main_v.101 (var_N2_a modified)
257
258 //////////////////////////////////////////////////////////////////////////////
259 //////////////////////////////////////////////////////////////////////////////
260 ////////////////////////////// THE SUBROUTINES ///////////////////////////////
261 //////////////////////////////////////////////////////////////////////////////
262 //////////////////////////////////////////////////////////////////////////////
263 //
264 // all new in v.102
265 // moved from 0x0D000 to 0x0C000 in v.108
266 #ifndef UNIX
267 # pragma code p2_deco = 0x0C000
268 #endif
269
270 //////////////////////////////////////////////////////////////////////////////
271 //////////////////////////////////////////////////////////////////////////////
272 /////////////////////// U T I L I T I E S /////////////////////////////////
273 //////////////////////////////////////////////////////////////////////////////
274 //////////////////////////////////////////////////////////////////////////////
275
276 //////////////////////////////////////////////////////////////////////////////
277 // Bump to blue-screen when an assert is wrong
278 #ifdef __DEBUG
279 void assert_failed(PARAMETER short int line)
280 {
281 }
282 #endif
283
284 //////////////////////////////////////////////////////////////////////////////
285 // When calling C code from ASM context, the data stack pointer and
286 // frames should be reset. Bank8 is used by stack
287
288 #ifdef CROSS_COMPILE
289 # define RESET_C_STACK
290 #else
291 # ifdef __DEBUG
292 # define RESET_C_STACK fillDataStack();
293 void fillDataStack(void)
294 {
295 _asm
296 LFSR 1,C_STACK
297 MOVLW 0xCC
298 loop: MOVWF POSTINC1,0
299 TSTFSZ FSR1L,0
300 BRA loop
301
302 LFSR 1,C_STACK
303 LFSR 2,C_STACK
304 _endasm
305 }
306 # else
307 # define RESET_C_STACK \
308 _asm \
309 LFSR 1, C_STACK \
310 LFSR 2, C_STACK \
311 _endasm
312 # endif
313 #endif
314
315 //////////////////////////////////////////////////////////////////////////////
316 // Fast subroutine to read timer 5.
317 // Note: result is in 1/32 of msecs (30,51757813µs/bit to be precise)
318 static unsigned short tmr5(void)
319 {
320 #ifndef CROSS_COMPILE
321 _asm
322 movff 0xf7c,PRODL // TMR5L
323 movff 0xf7d,PRODH // TMR5H
324 _endasm // result in PRODH:PRODL.
325 #else
326 return 0;
327 #endif
328 }
329
330
331 //////////////////////////////////////////////////////////////////////////////
332 // read buhlmann tables A and B for compatriment ci
333 //
334 static void read_buhlmann_coefficients(void)
335 {
336 #ifndef CROSS_COMPILE
337 // Note: we don't use far rom pointer, because the
338 // 24 bits is too complex, hence we have to set
339 // the UPPER page ourself...
340 // --> Set zero if tables are moved to lower pages !
341 _asm
342 movlw 1
343 movwf TBLPTRU,0
344 _endasm
345 #endif
346
347 assert( ci < NUM_COMP );
348
349 // Use an interleaved array (AoS) to access coefficients with a
350 // single addressing.
351 {
352 overlay rom const float* ptr = &buhlmann_ab[4*ci];
353 var_N2_a = *ptr++;
354 var_N2_b = *ptr++;
355 var_He_a = *ptr++;
356 var_He_b = *ptr++;
357 }
358 }
359
360 //////////////////////////////////////////////////////////////////////////////
361 // read buhlmann tables for compatriment ci
362 // If period == 0 : 2sec interval
363 // 1 : 1 min interval
364 // 2 : 10 min interval.
365 static void read_buhlmann_times(PARAMETER char period)
366 {
367 #ifndef CROSS_COMPILE
368 // Note: we don't use far rom pointer, because the
369 // 24 bits is to complex, hence we have to set
370 // the UPPER page ourself...
371 // --> Set zero if tables are moved to lower pages !
372 _asm
373 movlw 1
374 movwf TBLPTRU,0
375 _endasm
376 #endif
377
378 assert( ci < NUM_COMP );
379
380 // Integration intervals.
381 switch(period)
382 {
383 case 0: //---- 2 sec -----------------------------------------------------
384 {
385 overlay rom const float* ptr = &e2secs[2*ci];
386 var_N2_e = *ptr++;
387 var_He_e = *ptr++;
388 }
389 break;
390
391 case 1: //---- 1 min -----------------------------------------------------
392 {
393 overlay rom const float* ptr = &e1min[2*ci];
394 var_N2_e = *ptr++;
395 var_He_e = *ptr++;
396 }
397 break;
398
399 case 2: //---- 10 min ----------------------------------------------------
400 {
401 overlay rom const float* ptr = &e10min[2*ci];
402 var_N2_e = *ptr++;
403 var_He_e = *ptr++;
404 }
405 break;
406
407 default:
408 assert(0); // Never go there...
409 }
410 }
411
412 //////////////////////////////////////////////////////////////////////////////
413 // read buhlmann tables for compatriment ci
414 //
415 static void read_buhlmann_ht(void)
416 {
417
418 #ifndef CROSS_COMPILE
419 // Note: we don't use far rom pointer, because the
420 // 24 bits is to complex, hence we have to set
421 // the UPPER page ourself...
422 // --> Set zero if tables are moved to lower pages !
423 _asm
424 movlw 1
425 movwf TBLPTRU,0
426 _endasm
427 #endif
428
429 assert( ci < NUM_COMP );
430 {
431 overlay rom const float* ptr = &buhlmann_ht[2*ci];
432 var_N2_ht = *ptr++;
433 var_He_ht = *ptr++;
434 }
435
436 assert( 4.0 <= var_N2_ht && var_N2_ht <= 635.0 );
437 assert( 1.5099 <= var_He_ht && var_He_ht <= 240.03 );
438 }
439
440 //////////////////////////////////////////////////////////////////////////////
441 // calc_nextdecodepth
442 //
443 // new in v.102
444 //
445 // INPUT, changing during dive:
446 // temp_deco
447 // low_depth
448 //
449 // INPUT, fixed during dive:
450 // pres_surface
451 // GF_delta
452 // GF_high
453 // GF_low
454 // char_I_depth_last_deco
455 // float_deco_distance
456 //
457 // RETURN TRUE iff a stop is needed.
458 //
459 // OUTPUT
460 // locked_GF_step
461 // temp_depth_limt
462 // low_depth
463 //
464 static unsigned char calc_nextdecodepth(void)
465 {
466 //--- Max ascent speed ---------------------------------------------------
467 // Recompute leading gas limit, at current depth:
468 overlay float depth = (temp_deco - pres_surface) * BAR_TO_METER;
469
470 // At most, ascent 1 minute, at 10m/min == 10.0 m.
471 overlay float min_depth = (depth > 10.0) ? (depth - 10.0) : 0.0;
472
473 // Do we need to stop at current depth ?
474 overlay unsigned char need_stop = 0;
475
476 assert( depth >= -0.2 ); // Allow for 200mbar of weather change.
477
478 //---- ZH-L16 + GRADIENT FACTOR model ------------------------------------
479 if( char_I_deco_model != 0 )
480 {
481 overlay unsigned char first_stop = 0;
482 overlay float p;
483
484 sim_limit( GF_low );
485 p = sim_lead_tissue_limit - pres_surface;
486 if( p <= 0.0f )
487 goto no_deco_stop; // We can surface directly...
488
489 p *= BAR_TO_METER;
490 if( p < min_depth )
491 goto no_deco_stop; // First stop is higher than 1' ascent.
492
493 first_stop = 3 * (short)(0.99999 + p*0.333333);
494 assert( first_stop < 128 );
495
496 // Apply correction for the shallowest stop.
497 if( first_stop == 3 ) // new in v104
498 first_stop = char_I_depth_last_deco; // Use last 3m..6m instead.
499
500 // Store the deepest point needing a deco stop as the LOW reference for GF.
501 // NOTE: following stops will be validated using this LOW-HIGH gf scale,
502 // so if we want to keep coherency, we should not validate this stop
503 // yet, but apply the search to it, as for all the following stops afterward.
504 if( first_stop > low_depth )
505 {
506 low_depth = first_stop;
507 locked_GF_step = GF_delta / first_stop;
508 }
509
510 // We have a stop candidate.
511 // But maybe ascending to the next stop will diminish the constraint,
512 // because the GF might decrease more than the preassure gradient...
513 while(first_stop > 0)
514 {
515 overlay unsigned char next_stop; // Next depth (0..90m)
516 overlay float pres_stop; // Next pressure (bar)
517
518 // Check max speed, or reaching surface.
519 if( first_stop <= min_depth )
520 goto no_deco_stop;
521
522 if( first_stop <= char_I_depth_last_deco ) // new in v104
523 next_stop = 0;
524 else if( first_stop == 6 )
525 next_stop = char_I_depth_last_deco;
526 else
527 next_stop = first_stop - 3; // Index of next (upper) stop.
528
529 // Just a check we are indeed above LOW ref.
530 assert( next_stop < low_depth );
531
532 // Total preassure at the new stop candidate:
533 pres_stop = next_stop * METER_TO_BAR
534 + pres_surface;
535
536 // Keep GF_low until a first stop depth is found:
537 sim_limit( GF_high - next_stop * locked_GF_step );
538
539 // Check upper limit (lowest pressure tolerated):
540 if( sim_lead_tissue_limit >= pres_stop ) // check if ascent to next deco stop is ok
541 goto deco_stop_found;
542
543 // Else, validate that stop and loop...
544 first_stop = next_stop;
545 }
546 assert( first_stop == 0 );
547
548 no_deco_stop:
549 temp_depth_limit = min_depth;
550 goto done;
551
552 // next stop is the last validated depth found, aka first_stop
553 deco_stop_found:
554 need_stop = 1; // Hit.
555 temp_depth_limit = first_stop; // Stop depth, in meter.
556
557 done:
558 ;
559 }
560 else //---- ZH-L16 model -------------------------------------------------
561 {
562 overlay float pres_gradient;
563
564 // Original model
565 // optimized in v.101
566 // char_I_depth_last_deco included in v.101
567
568 // Compute sim_lead_tissue_limit too, but just once.
569 sim_limit(1.0);
570
571 pres_gradient = sim_lead_tissue_limit - pres_surface;
572 if (pres_gradient >= 0)
573 {
574 pres_gradient *= BAR_TO_METER/3; // Bar --> stop number;
575 temp_depth_limit = 3 * (short) (pres_gradient + 0.99); // --> metre : depth for deco
576 need_stop = 1; // Hit.
577
578 // Implement last stop at 4m/5m/6m...
579 if( temp_depth_limit == 3 )
580 temp_depth_limit = char_I_depth_last_deco;
581 }
582 else
583 temp_depth_limit = 0;
584 }
585
586 //---- Check gas change --------------------------------------------------
587 need_stop |= gas_switch_deepest(); // Update temp_depth_limit if there is a change,
588
589 return need_stop;
590 }
591
592 //////////////////////////////////////////////////////////////////////////////
593 // copy_deco_table
594 //
595 // Buffer the stops, once computed, so we can continue to display them
596 // while computing the next set.
597 //
598 static void copy_deco_table(void)
599 {
600 // Copy depth of the first (deepest) stop, because when reversing
601 // order, it will be hard to find...
602 char_O_first_deco_depth = internal_deco_depth[0] & 0x7F;
603 char_O_first_deco_time = internal_deco_time [0];
604
605 {
606 overlay unsigned char x, y;
607
608 for(x=0; x<NUM_STOPS; x++)
609 {
610 char_O_deco_depth[x] = internal_deco_depth[x];
611 char_O_deco_time [x] = internal_deco_time [x];
612 }
613
614 //Now fill the char_O_deco_time_for_log array
615 //---- First: search the first non-null depth
616 for(x=(NUM_STOPS-1); x != 0; --x)
617 if( internal_deco_depth[x] != 0 ) break;
618
619 //---- Second: copy to output table (in reverse order)
620 for(y=0; y<NUM_STOPS; y++, --x)
621 {
622 char_O_deco_time_for_log[y] = internal_deco_time [x];
623
624 // Stop only once the last transfer is done.
625 if( x == 0 ) break;
626 }
627
628 //---- Third: fill table end with null
629 for(y++; y<NUM_STOPS; y++)
630 {
631 char_O_deco_time_for_log [y] = 0;
632 }
633 }
634 }
635
636 //////////////////////////////////////////////////////////////////////////////
637 // temp_tissue_safety //
638 //
639 // outsourced in v.102
640 //
641 // Apply safety factors for brand ZH-L16 model.
642 //
643 static void temp_tissue_safety(void)
644 {
645 assert( 0.0 < float_desaturation_multiplier && float_desaturation_multiplier <= 1.0 );
646 assert( 1.0 <= float_saturation_multiplier && float_saturation_multiplier <= 2.0 );
647
648 if( char_I_deco_model == 0 )
649 {
650 if( temp_tissue < 0.0 )
651 temp_tissue *= float_desaturation_multiplier;
652 else
653 temp_tissue *= float_saturation_multiplier;
654 }
655 }
656
657 //////////////////////////////////////////////////////////////////////////////
658 //////////////////////////////////////////////////////////////////////////////
659 // ** THE JUMP-IN CODE **
660 // ** for the asm code **
661 //////////////////////////////////////////////////////////////////////////////
662 //////////////////////////////////////////////////////////////////////////////
663
664 //////////////////////////////////////////////////////////////////////////////
665 // Called every 2 seconds during diving.
666 // update tissues every time.
667 //
668 // Every 6 seconds (or slower when TTS > 16):
669 // - update deco table (char_O_deco_time/depth) with new values.
670 // - update ascent time,
671 // - set status to zero (so we can check there is new results).
672 //
673 void deco_calc_hauptroutine(void)
674 {
675 RESET_C_STACK
676 calc_hauptroutine();
677 int_O_desaturation_time = 65535;
678 }
679
680 //////////////////////////////////////////////////////////////////////////////
681 // Reset decompression model:
682 // + Set all tissues to equilibrium with Air at ambient pressure.
683 // + Reset last stop to 0m
684 // + Reset all model output.
685 void deco_clear_tissue(void)
686 {
687 RESET_C_STACK
688 clear_tissue();
689 }
690
691 //////////////////////////////////////////////////////////////////////////////
692 // Called every 1 min during decoplanning.
693 // Update tissues for 1 min.
694 //
695 void deco_calc_tissue(void)
696 {
697 RESET_C_STACK
698 calc_hauptroutine_update_tissues();
699 }
700
701 //////////////////////////////////////////////////////////////////////////////
702
703 void deco_calc_wo_deco_step_1_min(void)
704 {
705 RESET_C_STACK
706 calc_wo_deco_step_1_min();
707 deco_calc_desaturation_time();
708 }
709
710 //////////////////////////////////////////////////////////////////////////////
711
712 void deco_calc_dive_interval(void)
713 {
714 RESET_C_STACK
715 calc_dive_interval();
716 }
717
718 //////////////////////////////////////////////////////////////////////////////
719 // Find current gas in the list (if any).
720 //
721 // Input: char_I_current_gas = 1..6
722 //
723 // Output: sim_gas_last_depth = 0..5, temp_depth_limit.
724 //
725 static void gas_switch_find_current(void)
726 {
727 assert( 0 < char_I_current_gas && char_I_current_gas <= (NUM_GAS+1) );
728
729 if( char_I_current_gas <= NUM_GAS ) // Gas1..Gas5
730 {
731 sim_gas_last_used = char_I_current_gas;
732
733 // Note: if current is first gas, we must find it, but not set
734 // last depth change to surface.
735 if( char_I_deco_gas_change[sim_gas_last_used-1] )
736 sim_gas_last_depth = char_I_deco_gas_change[sim_gas_last_used-1];
737 }
738 else
739 sim_gas_last_used = 0; // Gas 6 = manual set
740 }
741
742 //////////////////////////////////////////////////////////////////////////////
743 // Find deepest available gas.
744 //
745 // Input: temp_depth_limit,
746 // deco_gas_change[]
747 // sim_gas_depth_used, sim_dive_mins.
748 //
749 // RETURNS TRUE if a stop is needed for gas switch.
750 //
751 // Output: temp_depth_limit, sim_gas_depth_used IFF the is a switch.
752 //
753 // NOTE: might be called from bottom (when sim_gas_delay and sim_gas_depth_used
754 // are null), or during the ascent to make sure we are not passing a
755 // stop (in which case both can be already set).
756 //
757 static unsigned char gas_switch_deepest(void)
758 {
759 overlay unsigned char switch_deco = 0, switch_last = 0;
760
761 if (char_I_const_ppO2 == 0)
762 {
763 overlay unsigned char j;
764
765 // Loop over all enabled gas, to find the deepest one,
766 // above last used gas, but below temp_depth_limit.
767 for(j=0; j<NUM_GAS; ++j)
768 {
769 // Gas not (yet) allowed ? Skip !
770 if( temp_depth_limit > deco_gas_change[j] )
771 continue;
772
773 // Gas deeper (or equal) than the current one ? Skip !
774 if( sim_gas_last_depth && deco_gas_change[j] >= sim_gas_last_depth )
775 continue;
776
777 // First, or deeper ?
778 if( switch_deco < deco_gas_change[j] )
779 {
780 switch_deco = deco_gas_change[j];
781 switch_last = j+1; // 1..5
782 }
783 }
784 }
785
786 // If there is a better gas available
787 if( switch_deco )
788 {
789 assert( !sim_gas_last_depth || sim_gas_last_depth > switch_deco );
790
791 sim_gas_last_depth = switch_deco;
792 sim_gas_last_used = switch_last;
793 return 0;
794 }
795 return 0;
796 }
797
798 //////////////////////////////////////////////////////////////////////////////
799 // Calculate gas switches
800 //
801 //
802 // Input: N2_ratio, He_ratio.
803 // sim_gas_last_used
804 //
805 // Output: calc_N2_ratio, calc_He_ratio
806 //
807 static void gas_switch_set(void)
808 {
809 assert( sim_gas_last_used <= NUM_GAS );
810
811 if( sim_gas_last_used == 0 ) // Gas6 = manualy set gas.
812 {
813 calc_N2_ratio = N2_ratio;
814 calc_He_ratio = He_ratio;
815 }
816 else
817 {
818 calc_N2_ratio = char_I_deco_N2_ratio[sim_gas_last_used-1] * 0.01;
819 calc_He_ratio = char_I_deco_He_ratio[sim_gas_last_used-1] * 0.01;
820 }
821
822 assert( 0.0 <= calc_N2_ratio && calc_N2_ratio <= 0.95 );
823 assert( 0.0 <= calc_He_ratio && calc_He_ratio <= 0.95 );
824 assert( (calc_N2_ratio + calc_He_ratio) <= 1.00 );
825 }
826
827 //////////////////////////////////////////////////////////////////////////////
828 //
829 // Input: calc_N2_ratio, calc_He_ratio : simulated gas mix.
830 // temp_deco : simulated respiration pressure
831 // float_deco_distance : security factor.
832 // Water-vapor pressure inside limbs (ppWater).
833 //
834 // Output: ppN2, ppHe.
835 //
836 static void sim_alveolar_presures(void)
837 {
838 overlay float deco_diluent = temp_deco; // new in v.101
839
840 // Take deco offset into account, but not at surface.
841 // Note: this should be done on ambiant pressure, hence before
842 // computing the diluant partial pressure...
843 if( deco_diluent > pres_surface )
844 deco_diluent += float_deco_distance;
845
846 //---- CCR mode : deco gas switch ? --------------------------------------
847 if( char_I_const_ppO2 != 0 )
848 {
849 // In CCR mode, use calc_XX_ratio instead of XX_ratio.
850 // Note: PPO2 and ratios are known outside the lumbs, so there is no
851 // ppWater in the equations below:
852 deco_diluent -= const_ppO2;
853 deco_diluent /= calc_N2_ratio + calc_He_ratio;
854
855 if (deco_diluent > temp_deco)
856 deco_diluent = temp_deco;
857 }
858
859 if( deco_diluent > ppWater )
860 {
861 ppN2 = calc_N2_ratio * (deco_diluent - ppWater);
862 ppHe = calc_He_ratio * (deco_diluent - ppWater);
863 }
864 else
865 {
866 ppN2 = 0.0;
867 ppHe = 0.0;
868 }
869 assert( 0.0 <= ppN2 && ppN2 < 14.0 );
870 assert( 0.0 <= ppHe && ppHe < 14.0 );
871 }
872
873 //////////////////////////////////////////////////////////////////////////////
874 // clear_tissue
875 //
876 // optimized in v.101 (var_N2_a)
877 //
878 // preload tissues with standard pressure for the given ambient pressure.
879 // Note: fixed N2_ratio for standard air.
880 //
881 static void clear_tissue(void)
882 {
883 overlay float p;
884
885 // Kludge: the 0.0002 of 0.7902 are missing with standard air.
886 N2_ratio = 0.7902;
887 pres_respiration = int_I_pres_respiration * 0.001;
888
889 p = N2_ratio * (pres_respiration - ppWater);
890 for(ci=0; ci<NUM_COMP; ci++)
891 {
892 // cycle through the 16 Bühlmann N2 tissues
893 pres_tissue_N2[ci] = p;
894
895 // cycle through the 16 Bühlmann tissues for Helium
896 pres_tissue_He[ci] = 0.0;
897 }
898
899 clear_deco_table();
900 // flag_in_divemode = 0;
901 char_O_deco_status = 0;
902 char_O_nullzeit = 0;
903 int_O_ascenttime = 0;
904 char_O_gradient_factor = 0;
905 char_O_relative_gradient_GF = 0;
906
907 calc_lead_tissue_limit = 0.0;
908 char_O_gtissue_no = 0;
909 }
910
911 //////////////////////////////////////////////////////////////////////////////
912 // calc_hauptroutine
913 //
914 // this is the major code in dive mode calculates:
915 // the tissues,
916 // the bottom time,
917 // and simulates the ascend with all deco stops.
918 //
919 // The deco_state sequence is :
920 // 3 (at surface)
921 // +---> 0 : calc nullzeit
922 // | 2 : simulate ascent to first stop (at 10m/min, less that 16x 1min simu)
923 // | +-> 1 : simulate up to 16min of stops.
924 // | +------< not finished
925 // +--------< finish
926 //
927 // Added steps 6,5 for @+5 calculation:
928 // 6 = ascent to first stop (same as 2), except continue to 7
929 // 7 = same as 1, except loop to 7.
930 //
931 static void calc_hauptroutine(void)
932 {
933 static unsigned char backup_gas_used;
934 static unsigned char backup_gas_depth;
935
936 calc_hauptroutine_data_input();
937
938 calc_hauptroutine_update_tissues();
939 calc_gradient_factor();
940
941 // toggle between calculation for nullzeit (bottom time),
942 // deco stops
943 // and more deco stops (continue)
944 switch( char_O_deco_status )
945 {
946 case 3: //---- At surface: start a new dive ------------------------------
947 clear_deco_table();
948 copy_deco_table();
949 int_O_ascenttime = 0; // Reset DTR.
950 int_O_extra_ascenttime = 0;
951 char_O_nullzeit = 0; // Reset bottom time.
952 char_O_deco_status = 0; // Calc bottom-time/nullzeit next iteration.
953
954 // Values that should be reset just once for the full real dive.
955 // This is used to record the lowest stop for the whole dive,
956 // Including ACCROSS all simulated ascent.
957 low_depth = 0;
958 locked_GF_step = 0.0;
959
960 // Reset gas switch history.
961 backup_gas_used = sim_gas_last_used = 0;
962 backup_gas_depth = sim_gas_last_depth = 0;
963 sim_dive_mins = 0;
964 break;
965
966 case 0: //---- bottom time -----------------------------------------------
967 default:
968 gas_switch_find_current(); // Lookup for current gas & time.
969 gas_switch_set(); // setup calc_ratio's
970
971 calc_nullzeit();
972 if( char_O_nullzeit > 0 ) // Some NDL time left ?
973 {
974 char_O_deco_status = 0; // YES: recalc ndl next time.
975 clear_deco_table(); // Also clear stops !
976 copy_deco_table();
977 char_O_deco_last_stop = 0; // And last stop (OSTC menu anim)
978 }
979 else
980 char_O_deco_status = 2; // NO: calc ascent next time.
981 break;
982
983 case 2: //---- Simulate ascent to first stop -----------------------------
984 case 6: // @+5min variation
985 // Check proposed gas at begin of ascent simulation
986 sim_dive_mins = int_I_divemins; // Init current time.
987
988 gas_switch_find_current(); // Lookup for current gas & time.
989 gas_switch_set(); // setup calc_ratio's
990
991 backup_gas_used = sim_gas_last_used; // And save for later simu steps.
992 backup_gas_depth = sim_gas_last_depth; // And save for later simu steps.
993
994 sim_ascent_to_first_stop();
995
996 // Calc stops next time (deco or gas switch).
997 char_O_deco_status = 1 | ( char_O_deco_status & 4 );
998 break;
999
1000 case 1: //---- Simulate stops --------------------------------------------
1001 case 5: // @+5 variation.
1002 calc_hauptroutine_calc_deco();
1003
1004 // If simulation is finished, restore the GF low reference, so that
1005 // next ascent simulation is done from the current depth:
1006 if( (char_O_deco_status & 3) == 0 )
1007 {
1008 sim_gas_last_used = backup_gas_used;
1009 sim_gas_last_depth = backup_gas_depth;
1010 }
1011 break;
1012 }
1013 }
1014
1015 //////////////////////////////////////////////////////////////////////////////
1016 // calc_hauptroutine_data_input
1017 //
1018 // Reset all C-code dive parameters from their ASM-code values.
1019 // Detect gas change condition.
1020 //
1021 void calc_hauptroutine_data_input(void)
1022 {
1023 overlay short int_temp;
1024 overlay unsigned char g;
1025
1026 pres_respiration = int_I_pres_respiration * 0.001;
1027 pres_surface = int_I_pres_surface * 0.001;
1028 N2_ratio = char_I_N2_ratio * 0.01;
1029 He_ratio = char_I_He_ratio * 0.01;
1030 float_deco_distance = char_I_deco_distance * 0.01; // Get offset is in mbar.
1031
1032 // ____________________________________________________
1033 //
1034 // _____________ G A S _ C H A N G E S ________________
1035 // ____________________________________________________
1036
1037 // Keep a margin of 150mbar = 1.50m
1038 int_temp = (int_I_pres_respiration - int_I_pres_surface)
1039 + MBAR_REACH_GASCHANGE_AUTO_CHANGE_OFF;
1040
1041 // Gas are selectable if we did not pass the change depth by more than 1.50m:
1042 for(g=0; g < NUM_GAS; ++g)
1043 {
1044 deco_gas_change[g] = 0;
1045 if(char_I_deco_gas_change[g])
1046 if( int_temp > 100 *(short)char_I_deco_gas_change[g] )
1047 deco_gas_change[g] = char_I_deco_gas_change[g];
1048 }
1049
1050 const_ppO2 = char_I_const_ppO2 * 0.01;
1051 float_desaturation_multiplier = char_I_desaturation_multiplier * 0.01;
1052 float_saturation_multiplier = char_I_saturation_multiplier * 0.01;
1053 GF_low = char_I_GF_Low_percentage * 0.01;
1054 GF_high = char_I_GF_High_percentage * 0.01;
1055 GF_delta = GF_high - GF_low;
1056 }
1057
1058 //////////////////////////////////////////////////////////////////////////////
1059 //
1060 //
1061 void calc_hauptroutine_update_tissues(void)
1062 {
1063 assert( 0.00 <= N2_ratio && N2_ratio <= 1.00 );
1064 assert( 0.00 <= He_ratio && He_ratio <= 1.00 );
1065 assert( (N2_ratio + He_ratio) <= 0.95 );
1066 assert( 0.800 < pres_respiration && pres_respiration < 14.0 );
1067
1068 pres_diluent = pres_respiration;
1069 if( char_I_const_ppO2 != 0 )
1070 {
1071 overlay float flush_ppO2 = pres_respiration * (1.0 - N2_ratio - He_ratio);
1072
1073 pres_diluent -= const_ppO2;
1074 pres_diluent /= N2_ratio + He_ratio;
1075 if( pres_diluent < 0.0 )
1076 pres_diluent = 0.0;
1077 if( pres_diluent > pres_respiration )
1078 pres_diluent = pres_respiration;
1079
1080 char_O_diluent = (unsigned char)(pres_diluent/pres_respiration*100.0 + 0.5);
1081
1082 if( flush_ppO2 > 2.545) flush_ppO2 = 2.55;
1083 if( flush_ppO2 < 0.0 ) flush_ppO2 = 0.0;
1084 char_O_flush_ppO2 = (unsigned char)(flush_ppO2*100.0 + 0.5);
1085 }
1086
1087 if( pres_diluent > ppWater )
1088 {
1089 overlay float EAD, END;
1090
1091 ppN2 = N2_ratio * (pres_diluent - ppWater);
1092 ppHe = He_ratio * (pres_diluent - ppWater);
1093
1094 // EAD : Equivalent Air Dive. Equivalent depth for the same N2 level
1095 // with plain air.
1096 // ppN2 = 79% * (P_EAD - ppWater)
1097 // EAD = (P_EAD - Psurface) * 10
1098 // ie: EAD = (ppN2 / 0.7902 + ppWater -Psurface) * 10
1099 EAD = (ppN2 / 0.7902 + ppWater - pres_surface) * BAR_TO_METER;
1100 if( EAD < 0.0 || EAD > 245.5 ) EAD = 0.0;
1101 char_O_EAD = (unsigned char)(EAD + 0.5);
1102
1103 // END : Equivalent Narcotic Dive.
1104 // Here we count O2 as narcotic too. Hence everything but helium (has a narcosis factor of
1105 // 0.23 btw). Hence the formula becomes:
1106 // END * BarPerMeter * (1.0 - 0.0) - ppWater + Psurface == Pambient - ppHe - ppWater
1107 // ie: END = (Pambient - ppHe - Psurface) * BAR_TO_METER
1108 //
1109 // Source cited:
1110 // The Physiology and Medicine of Diving by Peter Bennett and David Elliott,
1111 // 4th edition, 1993, W.B.Saunders Company Ltd, London.
1112 END = (pres_respiration - ppHe - pres_surface) * BAR_TO_METER;
1113 if( END < 0.0 || END > 245.5 ) END = 0.0;
1114 char_O_END = (unsigned char)(END + 0.5);
1115 }
1116 else // new in v.101
1117 {
1118 ppN2 = 0.0;
1119 ppHe = 0.0;
1120 char_O_EAD = char_O_END = 0;
1121 }
1122
1123 if(!char_I_step_is_1min)
1124 calc_tissue(0);
1125 else
1126 calc_tissue(1);
1127
1128 // Calc limit for surface, ie. GF_high.
1129 calc_limit();
1130
1131 int_O_gtissue_limit = (short)(calc_lead_tissue_limit * 1000);
1132 int_O_gtissue_press = (short)((pres_tissue_N2[char_O_gtissue_no] + pres_tissue_He[char_O_gtissue_no]) * 1000);
1133 }
1134
1135
1136 //////////////////////////////////////////////////////////////////////////////
1137 // Compute stops.
1138 //
1139 // Note: because this can be very long, break on 16 iterations, and set state
1140 // to 0 when finished, or to 1 when needing to continue.
1141 // Note: because each iteration might be very long too (~ 66 ms in 1.84beta),
1142 // break the loop when total time > 512msec.
1143 //
1144 void calc_hauptroutine_calc_deco(void)
1145 {
1146 overlay unsigned char loop;
1147
1148 for(loop = 0; loop < 32; ++loop)
1149 {
1150 // Limit loops to 512ms, using timer 5:
1151 if( tmr5() & (512*32) )
1152 break;
1153 // Do not ascent while doing a gas switch ?
1154 if( calc_nextdecodepth() )
1155 {
1156 if( temp_depth_limit == 0 )
1157 goto Surface;
1158
1159 //---- We hit a stop at temp_depth_limit ---------------------
1160 temp_deco = temp_depth_limit * METER_TO_BAR // Convert to relative bar,
1161 + pres_surface; // To absolute.
1162 if( !update_deco_table() ) // Adds a one minute stops.
1163 goto Surface; // Deco table full: abort...
1164 }
1165 else
1166 {
1167 //---- No stop -----------------------------------------------
1168 temp_deco -= (10*METER_TO_BAR); // Ascend 10m, no wait.
1169
1170 //---- Finish computations once surface is reached -----------
1171 if( temp_deco <= pres_surface )
1172 {
1173 Surface:
1174 if( char_O_deco_status == 1 ) // Don't in @+5min variant.
1175 copy_deco_table();
1176
1177 calc_ascenttime();
1178 char_O_deco_status = 0; // calc nullzeit next time.
1179 char_O_deco_last_stop = 0; // Surface reached (to animate menu)
1180 return;
1181 }
1182 }
1183 //---- Then update tissue --------------------------------------------
1184 sim_dive_mins++; // Advance simulated time by 1 minute.
1185 gas_switch_set(); // Apply any simulated gas change, once validated.
1186 sim_alveolar_presures(); // Updates ppN2 and ppHe.
1187 sim_tissue(1); // Simulate compartiments for 1 minute.
1188 }
1189
1190 // Surface not reached, need more stops... for menu animation.
1191 char_O_deco_last_stop = temp_depth_limit; // Reached depth.
1192 }
1193
1194
1195 //////////////////////////////////////////////////////////////////////////////
1196 // Simulation ascention to first deco stop.
1197 //
1198 // Note: because we ascent with a constant speed (10m/mn, ie. 1bar/mn),
1199 // there is no need to break on more that 16 iterations
1200 // (or we are already in deep shit).
1201 //
1202 // Input: pres_respiration
1203 // Output: temp_deco
1204 //
1205 // if char_O_deco_status indicate @+5 variant, add extra time at current depth,
1206 // before ascent.
1207 void sim_ascent_to_first_stop(void)
1208 {
1209 overlay unsigned char fast = 1; // 1min or 2sec steps.
1210
1211 update_startvalues();
1212 clear_deco_table();
1213
1214 temp_deco = pres_respiration; // Starts from current real depth.
1215
1216 // Are we doing the special @+5min variation ?
1217 if(char_O_deco_status & 4)
1218 sim_extra_time();
1219
1220 //---- Loop until first stop, gas switch, or surface is reached ----------
1221 for(;;)
1222 {
1223 overlay float old_deco = temp_deco; // Pamb backup (bars)
1224
1225 // Try ascending 1 full minute (fast) or 2sec (!fast):
1226 if( fast )
1227 temp_deco -= 10*METER_TO_BAR; // 1 min, at 10m/min. ~ 1bar.
1228 else
1229 temp_deco -= (10.0/30.0)*METER_TO_BAR; // 2sec at 10m/min.
1230
1231 if( temp_deco < pres_surface ) // But don't go over surface.
1232 temp_deco = pres_surface;
1233
1234 // Recompute sim_lead_tissue_limit at GF_low (deepest stop), because
1235 // one minute passed.
1236 sim_limit(GF_low);
1237
1238 // Did we reach deepest remaining stop ?
1239 if( temp_deco < sim_lead_tissue_limit )
1240 {
1241 temp_deco = old_deco; // Restore last correct depth,
1242
1243 if( fast )
1244 {
1245 fast = 0; // Retry with 2sec steps.
1246 continue;
1247 }
1248 else
1249 break; // Done...
1250 }
1251
1252 // Did we reach surface ?
1253 // NOTE: we should round BEFORE checking surface is reached.
1254 temp_depth_limit = (unsigned char)(0.5 + (temp_deco - pres_surface) * BAR_TO_METER);
1255 if( temp_depth_limit == 0 )
1256 {
1257 temp_deco = pres_surface; // Yes: finished !
1258 break;
1259 }
1260
1261 // Check for gas change below new depth ?
1262 if( gas_switch_deepest() )
1263 {
1264 assert( temp_depth_limit > 0);
1265
1266 temp_deco = temp_depth_limit * METER_TO_BAR + pres_surface;
1267 break;
1268 }
1269
1270 if( fast )
1271 sim_dive_mins++; // Advance simulated time by 1 minute.
1272 sim_alveolar_presures(); // temp_deco --> ppN2/ppHe
1273 sim_tissue(fast); // and update tissues for 1 min.
1274 }
1275 }
1276
1277 //////////////////////////////////////////////////////////////////////////////
1278 // Simulation extra time at the current depth.
1279 //
1280 // This routine is used for @+5min feature.
1281 void sim_extra_time(void)
1282 {
1283 overlay unsigned char extra = char_I_extra_time;
1284 do {
1285 sim_dive_mins++; // Advance simulated time by 1 minute.
1286 sim_tissue(1); // and update tissues for 1 min.
1287 } while( --extra != 0 );
1288 }
1289
1290 //////////////////////////////////////////////////////////////////////////////
1291 // calc_tissue
1292 //
1293 // optimized in v.101
1294 //
1295 static void calc_tissue(PARAMETER unsigned char period)
1296 {
1297 assert( 0.00 <= ppN2 && ppN2 < 11.2 ); // 80% N2 at 130m
1298 assert( 0.00 <= ppHe && ppHe < 12.6 ); // 90% He at 130m
1299
1300 for (ci=0;ci<NUM_COMP;ci++)
1301 {
1302 read_buhlmann_times(period); // 2 sec or 1 min period.
1303
1304 // N2
1305 temp_tissue = (ppN2 - pres_tissue_N2[ci]) * var_N2_e;
1306 temp_tissue_safety();
1307 pres_tissue_N2[ci] += temp_tissue;
1308
1309 // He
1310 temp_tissue = (ppHe - pres_tissue_He[ci]) * var_He_e;
1311 temp_tissue_safety();
1312 pres_tissue_He[ci] += temp_tissue;
1313 }
1314 }
1315
1316 //////////////////////////////////////////////////////////////////////////////
1317 // calc_limit
1318 //
1319 // New in v.111 : separated from calc_tissue(), and depends on GF value.
1320 //
1321 static void calc_limit(void)
1322 {
1323 char_O_gtissue_no = 255;
1324 calc_lead_tissue_limit = 0.0;
1325
1326 for(ci=0; ci<NUM_COMP;ci++)
1327 {
1328 overlay float N2 = pres_tissue_N2[ci];
1329 overlay float He = pres_tissue_He[ci];
1330 overlay float p = N2 + He;
1331
1332 read_buhlmann_coefficients();
1333 var_N2_a = (var_N2_a * N2 + var_He_a * He) / p;
1334 var_N2_b = (var_N2_b * N2 + var_He_b * He) / p;
1335
1336 // Apply the Eric Baker's varying gradient factor correction.
1337 // Note: the correction factor depends both on GF and b,
1338 // Actual values are in the 1.5 .. 1.0 range (for a GF=30%),
1339 // so that can change who is the leading gas...
1340 // Note: Also depends of the GF. So the calcul is different for
1341 // GF_low, current GF, or GF_high...
1342 // *BUT* calc_tissue() is used to compute bottom time,
1343 // hence what would happend at surface,
1344 // hence at GF_high.
1345 if( char_I_deco_model != 0 )
1346 p = ( p - var_N2_a * GF_high) * var_N2_b
1347 / (GF_high + var_N2_b * (1.0 - GF_high));
1348 else
1349 p = (p - var_N2_a) * var_N2_b;
1350 if( p < 0.0 ) p = 0.0;
1351
1352 if( p > calc_lead_tissue_limit )
1353 {
1354 char_O_gtissue_no = ci;
1355 calc_lead_tissue_limit = p;
1356 }
1357 }
1358
1359 assert( char_O_gtissue_no < NUM_COMP );
1360 assert( 0.0 <= calc_lead_tissue_limit && calc_lead_tissue_limit <= 14.0);
1361 }
1362
1363 //////////////////////////////////////////////////////////////////////////////
1364 // calc_nullzeit
1365 //
1366 // calculates the remaining bottom time
1367 //
1368 // NOTE: Erik Baker's closed formula works for Nitroxes. Trimix adds a second
1369 // exponential term to the M-value equation, making it impossible to
1370 // invert... So we have to make a fast-simu until we find a better way.
1371 //
1372 // Input: pres_respiration
1373 // Output: char_O_nullzeit
1374 //
1375 static void calc_nullzeit(void)
1376 {
1377 //---- Compute ppN2 and ppHe ---------------------------------------------
1378 temp_deco = pres_respiration;
1379 sim_alveolar_presures();
1380
1381 char_O_nullzeit = 240;
1382 for(ci=0; ci<NUM_COMP; ci++)
1383 {
1384 //---- Read A/B values and loading factor for N2 and He --------------
1385 overlay float tN2 = pres_tissue_N2[ci];
1386 overlay float tHe = pres_tissue_He[ci];
1387 overlay float t = tN2 + tHe;
1388 overlay unsigned char ndl;
1389 overlay unsigned char period = 10;
1390
1391 read_buhlmann_coefficients();
1392 read_buhlmann_times(2); // Starts with a 10min period.
1393
1394 //---- Simulate for that tissue --------------------------------------
1395 // NOTE: No need to simulate for longuer than the already found NDL.
1396 for(ndl=0; ndl<char_O_nullzeit;)
1397 {
1398 //---- Compute updated mix M-value at surface
1399 overlay float a = (var_N2_a * tN2 + var_He_a * tHe) / t;
1400 overlay float b = (var_N2_b * tN2 + var_He_b * tHe) / t;
1401 overlay float M0 = (a + pres_surface/b);
1402
1403 //---- Add 10min/1min to N2/He tissues
1404 overlay float dTN2 = (ppN2 - tN2) * var_N2_e;
1405 overlay float dTHe = (ppHe - tHe) * var_He_e;
1406
1407 //---- Apply security margin when using the non-GF model
1408 if( char_I_deco_model == 0 )
1409 {
1410 dTN2 *= float_saturation_multiplier;
1411 dTHe *= float_saturation_multiplier;
1412 }
1413 else // Or GF-based model
1414 M0 = GF_high * (M0 - pres_surface) + pres_surface;
1415
1416 //---- Simulate off-gasing while going to surface
1417 // TODO !
1418 // dTN2 -= exp( ... ascent time ... ppN2...)
1419 // dTHe -= exp( ... ascent time ... ppHe...)
1420
1421 //---- Ok now, and still ok to surface after 1 or 10 minutes ?
1422 if( (t <= M0) && (t + dTN2 + dTHe <= M0) )
1423 {
1424 tN2 += dTN2; // YES: apply gas loadings,
1425 tHe += dTHe;
1426 t = tN2 + tHe;
1427 ndl += period; // increment NDL,
1428 continue; // and loop.
1429 }
1430
1431 //---- Should we retry with smaller steps ?
1432 if( period == 10 )
1433 {
1434 read_buhlmann_times(1); // 1min coefs.
1435 period = 1;
1436 continue;
1437 }
1438
1439 //---- ELSE make a linear approx for the last minute
1440 // Usefull to have a meaningfull rounding of NDL.
1441 // But ONLY it positive (negativ casted to unsigned is bad).
1442 if( M0 > t )
1443 ndl += (unsigned char)(0.5f + (M0-t)/(dTN2+dTHe));
1444 break;
1445 }
1446
1447 // Keep the shortest NDL found
1448 if( ndl < char_O_nullzeit )
1449 char_O_nullzeit = ndl;
1450 }
1451 }
1452
1453 //////////////////////////////////////////////////////////////////////////////
1454 // calc_ascenttime
1455 //
1456 // Summup ascent from bottom to surface, at 1 bar/min, 1min for last 3 meters,
1457 // and all stops.
1458 //
1459 // Result in int_O_ascenttime, or int_O_extra_ascenttime if in @+5min variant.
1460 static void calc_ascenttime(void)
1461 {
1462 overlay unsigned char x;
1463 overlay unsigned short sum;
1464
1465 // + 0.7 to count 1 minute ascent time from 3 metre to surface
1466 overlay float ascent = pres_respiration - pres_surface + 0.7;
1467 if (ascent < 0.0)
1468 ascent = 0.0;
1469 sum = (unsigned short)(ascent + 0.99);
1470
1471 for(x=0; x<NUM_STOPS && internal_deco_depth[x]; x++)
1472 sum += (unsigned short)internal_deco_time[x];
1473
1474 if( char_O_deco_status == 1 )
1475 int_O_ascenttime = sum;
1476 else
1477 int_O_extra_ascenttime = sum;
1478
1479 if(int_O_ascenttime>999)
1480 int_O_ascenttime=999; // limit to 999'
1481 }
1482
1483 //////////////////////////////////////////////////////////////////////////////
1484 // update_startvalues
1485 //
1486 // updated in v.102
1487 //
1488 void update_startvalues(void)
1489 {
1490 overlay unsigned char x;
1491
1492 // Start ascent simulation with current tissue partial pressures.
1493 for(x=0; x<NUM_COMP; x++)
1494 {
1495 sim_pres_tissue_N2[x] = pres_tissue_N2[x];
1496 sim_pres_tissue_He[x] = pres_tissue_He[x];
1497 }
1498
1499 // No leading tissue (yet) for this ascent simulation.
1500 sim_lead_tissue_limit = 0.0;
1501 sim_lead_tissue_no = 255;
1502 }
1503
1504 //////////////////////////////////////////////////////////////////////////////
1505 // sim_tissue
1506 //
1507 // optimized in v.101
1508 //
1509 // Function very simular to calc_tissue, but:
1510 // + Use a 1min or 10min period.
1511 // + Do it on sim_pres_tissue, instead of pres_tissue.
1512 static void sim_tissue(PARAMETER unsigned char period)
1513 {
1514 assert( 0.00 <= ppN2 && ppN2 < 11.2 ); // 80% N2 at 130m
1515 assert( 0.00 <= ppHe && ppHe < 12.6 ); // 90% He at 130m
1516
1517 for(ci=0; ci<NUM_COMP; ci++)
1518 {
1519 read_buhlmann_times(period); // 1 or 10 minute(s) interval
1520
1521 // N2
1522 temp_tissue = (ppN2 - sim_pres_tissue_N2[ci]) * var_N2_e;
1523 temp_tissue_safety();
1524 sim_pres_tissue_N2[ci] += temp_tissue;
1525
1526 // He
1527 temp_tissue = (ppHe - sim_pres_tissue_He[ci]) * var_He_e;
1528 temp_tissue_safety();
1529 sim_pres_tissue_He[ci] += temp_tissue;
1530 }
1531 }
1532
1533 //////////////////////////////////////////////////////////////////////////////
1534 // sim_limit()
1535 //
1536 // New in v.111
1537 //
1538 // Function separated from sim_tissue() to allow recomputing limit on
1539 // different depth, because it depends on current gradient factor.
1540 //
1541 static void sim_limit(PARAMETER float GF_current)
1542 {
1543 assert( 0.0 < GF_current && GF_current <= 1.0f);
1544
1545 sim_lead_tissue_limit = 0.0;
1546 sim_lead_tissue_no = 0; // If no one is critic, keep first tissue.
1547
1548 for(ci=0; ci<NUM_COMP; ci++)
1549 {
1550 overlay float N2 = sim_pres_tissue_N2[ci];
1551 overlay float He = sim_pres_tissue_He[ci];
1552 overlay float p = N2 + He;
1553
1554 read_buhlmann_coefficients();
1555 var_N2_a = (var_N2_a * N2 + var_He_a * He) / p;
1556 var_N2_b = (var_N2_b * N2 + var_He_b * He) / p;
1557
1558 // Apply the Eric Baker's varying gradient factor correction.
1559 // Note: the correction factor depends both on GF and b,
1560 // Actual values are in the 1.5 .. 1.0 range (for a GF=30%),
1561 // so that can change who is the leading gas...
1562 // Note: Also depends of the GF_current...
1563 if( char_I_deco_model != 0 )
1564 p = ( p - var_N2_a * GF_current)
1565 / (GF_current / var_N2_b + 1.0 - GF_current);
1566 else
1567 p = (p - var_N2_a) * var_N2_b;
1568 if( p < 0.0 ) p = 0.0;
1569
1570 if( p > sim_lead_tissue_limit )
1571 {
1572 sim_lead_tissue_no = ci;
1573 sim_lead_tissue_limit = p;
1574 }
1575 } // for ci
1576
1577 assert( sim_lead_tissue_no < NUM_COMP );
1578 assert( 0.0 <= sim_lead_tissue_limit && sim_lead_tissue_limit <= 14.0 );
1579 }
1580
1581 //////////////////////////////////////////////////////////////////////////////
1582 // clear_deco_table
1583 //
1584 // unchanged in v.101
1585 //
1586 static void clear_deco_table(void)
1587 {
1588 overlay unsigned char x;
1589
1590 for(x=0; x<NUM_STOPS; ++x)
1591 {
1592 internal_deco_time [x] = 0;
1593 internal_deco_depth[x] = 0;
1594 }
1595 }
1596
1597 //////////////////////////////////////////////////////////////////////////////
1598 // update_deco_table
1599 //
1600 // Add 1 min to current stop.
1601 //
1602 // Inputs:
1603 // temp_depth_limit = stop's depth, in meters.
1604 // In/Out:
1605 // internal_deco_depth[] : depth (in metres) of each stops.
1606 // internal_deco_time [] : time (in minutes) of each stops.
1607 //
1608 static unsigned char update_deco_table()
1609 {
1610 overlay unsigned char x;
1611 assert( temp_depth_limit < 128 ); // Can't be negativ (overflown).
1612 assert( temp_depth_limit > 0 ); // No stop at surface...
1613
1614 for(x=0; x<NUM_STOPS; ++x)
1615 {
1616 // Make sure deco-stops are recorded in order:
1617 assert( !internal_deco_depth[x] || temp_depth_limit <= (internal_deco_depth[x]& 0x7F) );
1618
1619 if( (internal_deco_depth[x] & 0x7F) == temp_depth_limit )
1620 {
1621 // Do not overflow (max 255')
1622 if( internal_deco_time[x] < 255 )
1623 {
1624 internal_deco_time[x]++;
1625 return 1;
1626 }
1627 // But store extra in the next stop...
1628 }
1629
1630 if( internal_deco_depth[x] == 0 )
1631 {
1632 internal_deco_depth[x] = temp_depth_limit;
1633
1634 internal_deco_time[x] = 1;
1635 return 1;
1636 }
1637 }
1638
1639 // Can't store stops at more than 96m.
1640 // Or stops at less that 3m too.
1641 // Just do nothing with that...
1642 return 0;
1643 }
1644
1645 //////////////////////////////////////////////////////////////////////////////
1646 // calc_gradient_factor
1647 //
1648 // optimized in v.101 (var_N2_a)
1649 // new code in v.102
1650 //
1651 static void calc_gradient_factor(void)
1652 {
1653 overlay float gf;
1654 overlay float N2 = pres_tissue_N2[char_O_gtissue_no];
1655 overlay float He = pres_tissue_He[char_O_gtissue_no];
1656
1657 assert( char_O_gtissue_no < NUM_COMP );
1658 assert( 0.800 <= pres_respiration && pres_respiration < 14.0 );
1659
1660 // tissue > respiration (currently off-gasing)
1661 // GF = 0% when respiration == tissue, ie. bubbles are at equilibrium.
1662 // GF = 100% when respiration == limit.
1663 temp_tissue = N2 + He;
1664 if( temp_tissue <= pres_respiration )
1665 gf = 0.0;
1666 else
1667 {
1668 overlay float limit = calc_lead_tissue_limit;
1669 // NOTE: in GF model, calc_lead_tissue_limit include already the
1670 // correction due to gradient factor. To compute the actual
1671 // current GF, we need to (re-)compute the raw ambiant-pressure
1672 // limit from the Bühlmann model.
1673 if( char_I_deco_model != 0 )
1674 {
1675 ci = char_O_gtissue_no;
1676 read_buhlmann_coefficients();
1677 var_N2_a = (var_N2_a * N2 + var_He_a * He) / temp_tissue;
1678 var_N2_b = (var_N2_b * N2 + var_He_b * He) / temp_tissue;
1679 limit = (temp_tissue - var_N2_a) * var_N2_b;
1680 }
1681
1682 gf = (temp_tissue - pres_respiration)
1683 / (temp_tissue - limit)
1684 * 100.0;
1685 if( gf > 254.5 ) gf = 255.0;
1686 if( gf < 0.0 ) gf = 0.0;
1687 }
1688 char_O_gradient_factor = (unsigned char)(gf+0.5f);
1689
1690 if( char_I_deco_model != 0 ) // calculate relative gradient factor
1691 {
1692 overlay float rgf;
1693
1694 if( low_depth < 3 )
1695 rgf = GF_high;
1696 else
1697 {
1698 overlay float temp1 = low_depth * METER_TO_BAR;
1699 overlay float temp2 = pres_respiration - pres_surface;
1700
1701 if (temp2 <= 0)
1702 rgf = GF_high;
1703 else if (temp2 >= temp1)
1704 rgf = GF_low;
1705 else
1706 rgf = GF_low + (temp1 - temp2)/temp1*GF_delta;
1707 }
1708
1709 rgf = gf / rgf; // gf is already in percent
1710 if( rgf < 0.0 ) rgf = 0.0;
1711 if( rgf > 254.5 ) rgf = 255.0;
1712 char_O_relative_gradient_GF = (unsigned char)(rgf+0.5f);
1713 }
1714 else
1715 char_O_relative_gradient_GF = char_O_gradient_factor;
1716 }
1717
1718 //////////////////////////////////////////////////////////////////////////////
1719 // deco_calc_desaturation_time
1720 //
1721 // FIXED N2_ratio
1722 // unchanged in v.101
1723 // Inputs: int_I_pres_surface, ppWater, char_I_desaturation_multiplier
1724 // Outputs: int_O_desaturation_time, char_O_tissue_saturation[0..31]
1725 //
1726 void deco_calc_desaturation_time(void)
1727 {
1728 RESET_C_STACK
1729
1730 assert( 800 < int_I_pres_surface && int_I_pres_surface < 1100 );
1731 assert( 0 < char_I_desaturation_multiplier && char_I_desaturation_multiplier <= 100 );
1732
1733 N2_ratio = 0.7902; // FIXED sum as stated in bühlmann
1734 pres_surface = int_I_pres_surface * 0.001;
1735 ppN2 = N2_ratio * (pres_surface - ppWater);
1736 int_O_desaturation_time = 0;
1737 float_desaturation_multiplier = char_I_desaturation_multiplier * (0.01 * SURFACE_DESAT_FACTOR);
1738
1739 for(ci=0; ci<NUM_COMP; ci++)
1740 {
1741 overlay unsigned short desat_time; // For a particular compartiment, in min.
1742 overlay float temp1;
1743 overlay float temp2;
1744 overlay float temp3;
1745 overlay float temp4;
1746
1747 read_buhlmann_ht();
1748
1749 // saturation_time (for flight) and N2_saturation in multiples of halftime
1750 // version v.100: 1.1 = 10 percent distance to totally clean (totally clean is not possible, would take infinite time )
1751 // new in version v.101: 1.07 = 7 percent distance to totally clean (totally clean is not possible, would take infinite time )
1752 // changes in v.101: 1.05 = 5 percent dist to totally clean is new desaturation point for display and NoFly calculations
1753 // N2
1754 temp1 = 1.05 * ppN2 - pres_tissue_N2[ci];
1755 temp2 = ppN2 - pres_tissue_N2[ci];
1756 if (temp2 >= 0.0)
1757 temp1 = 0.0;
1758 else
1759 temp1 = temp1 / temp2;
1760
1761 if( 0.0 < temp1 && temp1 < 1.0 )
1762 {
1763 // 0.6931 is ln(2), because the math function log() calculates with a base of e not 2 as requested.
1764 // minus because log is negative.
1765 temp1 = log(1.0 - temp1) / -0.6931; // temp1 is the multiples of half times necessary.
1766 temp2 = var_N2_ht * temp1 / float_desaturation_multiplier; // time necessary (in minutes ) for complete desaturation (see comment about 5 percent)
1767 }
1768 else
1769 {
1770 temp1 = 0.0;
1771 temp2 = 0.0;
1772 }
1773
1774 // He
1775 temp3 = 0.1 - pres_tissue_He[ci];
1776 if (temp3 >= 0.0)
1777 temp3 = 0.0;
1778 else
1779 temp3 = - temp3 / pres_tissue_He[ci];
1780
1781 if( 0.0 < temp3 && temp3 < 1.0 )
1782 {
1783 temp3 = log(1.0 - temp3) / -0.6931; // temp1 is the multiples of half times necessary.
1784 // 0.6931 is ln(2), because the math function log() calculates with a base of e not 2 as requested.
1785 // minus because log is negative
1786 temp4 = var_He_ht * temp3 / float_desaturation_multiplier; // time necessary (in minutes ) for "complete" desaturation, new in v.101 float_desaturation_multiplier
1787 }
1788 else
1789 {
1790 temp3 = 0.0;
1791 temp4 = 0.0;
1792 }
1793
1794 // saturation_time (for flight)
1795 if (temp4 > temp2)
1796 desat_time = (unsigned short)temp4;
1797 else
1798 desat_time = (unsigned short)temp2;
1799
1800 if(desat_time > int_O_desaturation_time)
1801 int_O_desaturation_time = desat_time;
1802
1803 // N2 saturation in multiples of halftime for display purposes
1804 temp2 = temp1 * 20.0; // 0 = 1/8, 120 = 0, 249 = 8
1805 temp2 = temp2 + 80.0; // set center
1806 if (temp2 < 0.0)
1807 temp2 = 0.0;
1808 if (temp2 > 255.0)
1809 temp2 = 255.0;
1810 char_O_tissue_N2_saturation[ci] = (char)temp2;
1811
1812 // He saturation in multiples of halftime for display purposes
1813 temp4 = temp3 * 20.0; // 0 = 1/8, 120 = 0, 249 = 8
1814 temp4 = temp4 + 80.0; // set center
1815 if (temp4 < 0.0)
1816 temp4 = 0.0;
1817 if (temp4 > 255.0)
1818 temp4 = 255.0;
1819 char_O_tissue_He_saturation[ci] = (char)temp4;
1820 } // for
1821 }
1822
1823 //////////////////////////////////////////////////////////////////////////////
1824 // calc_wo_deco_step_1_min
1825 //
1826 // FIXED N2 Ratio
1827 // optimized in v.101 (...saturation_multiplier)
1828 // desaturation slowed down to 70,42%
1829 //
1830 static void calc_wo_deco_step_1_min(void)
1831 {
1832 assert( 800 < int_I_pres_surface && int_I_pres_surface < 1100 );
1833 assert( 800 < int_I_pres_respiration && int_I_pres_respiration < 1100 );
1834 assert( 100 <= char_I_saturation_multiplier && char_I_saturation_multiplier < 200 );
1835 assert( 0 < char_I_desaturation_multiplier && char_I_desaturation_multiplier <= 100 );
1836
1837 N2_ratio = 0.7902; // FIXED, sum lt. buehlmann
1838 pres_respiration = pres_surface = int_I_pres_surface * 0.001;
1839 ppN2 = N2_ratio * (pres_respiration - ppWater);
1840 ppHe = 0.0;
1841 float_desaturation_multiplier = char_I_desaturation_multiplier * (0.01 * SURFACE_DESAT_FACTOR);
1842 float_saturation_multiplier = char_I_saturation_multiplier * 0.01;
1843
1844 calc_tissue(1); // update the pressure in the tissues N2/He in accordance with the new ambient pressure
1845
1846 clear_deco_table();
1847 char_O_deco_status = 3; // surface new in v.102 : stays in surface state.
1848 char_O_nullzeit = 0;
1849 int_O_ascenttime = 0;
1850 int_O_extra_ascenttime = 0;
1851 calc_gradient_factor();
1852 }
1853
1854 //////////////////////////////////////////////////////////////////////////////
1855 // calc_dive_interval
1856 //
1857 // Prepare tissue for delay before the next dive simulation.
1858 //
1859 // Inputs: char_I_dive_interval == delay before dive (in 10' steps).
1860 // Outputs: pres_tissue_N2/He[], CNS_fraction
1861 //
1862 // Should be protected by deco_push_tissues_to_vault(),
1863 // deco_pull_tissues_from_vault()
1864 //
1865 // desaturation slowed down to 70,42%.
1866 //
1867 static void calc_dive_interval(void)
1868 {
1869 overlay unsigned char t;
1870 overlay unsigned char backup_model;
1871
1872 //---- Initialize simulation parameters ----------------------------------
1873 N2_ratio = 0.7902; // FIXED, sum lt. buehlmann
1874 pres_respiration = pres_surface = int_I_pres_surface * 0.001;
1875 ppN2 = N2_ratio * (pres_respiration - ppWater);
1876 ppHe = 0.0;
1877 float_desaturation_multiplier = char_I_desaturation_multiplier * (0.01 * SURFACE_DESAT_FACTOR);
1878 float_saturation_multiplier = char_I_saturation_multiplier * 0.01;
1879
1880 // Make sure SURFACE_DESAT_FACTOR is applied:
1881 backup_model = char_I_deco_model;
1882 char_I_deco_model = 0;
1883
1884 //---- Perform simulation ------------------------------------------------
1885 for(t=0; t<char_I_dive_interval; ++t)
1886 {
1887 calc_tissue(2); // period = 10min.
1888 CNS_fraction = 0.92587471 * CNS_fraction; // Half-time = 90min: (1/2)^(1/9)
1889 }
1890 assert( 0.0 <= CNS_fraction && CNS_fraction <= 2.56 );
1891 int_O_CNS_fraction = (unsigned int)(CNS_fraction * 100.0 + 0.5);
1892
1893 //---- Restore model -----------------------------------------------------
1894 char_I_deco_model = backup_model;
1895 }
1896
1897 //////////////////////////////////////////////////////////////////////////////
1898 // deco_clear_CNS_fraction
1899 //
1900 // new in v.101
1901 //
1902 void deco_clear_CNS_fraction(void)
1903 {
1904 RESET_C_STACK
1905
1906 CNS_fraction = 0.0;
1907 int_O_CNS_fraction = 0;
1908 }
1909
1910 //////////////////////////////////////////////////////////////////////////////
1911 // deco_calc_CNS_fraction
1912 //
1913 // Input: char_I_actual_ppO2 : Current condition (in decibars).
1914 // char_I_step_is_1min : use 1min or 10min steps instead of 2sec.
1915 // CNS_fraction : velue before period.
1916 // Output: CNS_fraction, int_O_CNS_fraction
1917 //
1918 void deco_calc_CNS_fraction(void)
1919 {
1920 overlay float time_factor = 1.0f;
1921 RESET_C_STACK
1922
1923 assert( 0.0 <= CNS_fraction && CNS_fraction <= 2.56 );
1924 assert( char_I_actual_ppO2 > 15 );
1925
1926 if( char_I_step_is_1min == 1 )
1927 time_factor = 30.0f;
1928 else if( char_I_step_is_1min == 2 )
1929 time_factor = 300.0f;
1930
1931 if (char_I_actual_ppO2 < 50)
1932 ; // no changes
1933 else if (char_I_actual_ppO2 < 60)
1934 CNS_fraction += time_factor/(-540.0 * char_I_actual_ppO2 + 54000.0);
1935 else if (char_I_actual_ppO2 < 70)
1936 CNS_fraction += time_factor/(-450.0 * char_I_actual_ppO2 + 48600.0);
1937 else if (char_I_actual_ppO2 < 80)
1938 CNS_fraction += time_factor/(-360.0 * char_I_actual_ppO2 + 42300.0);
1939 else if (char_I_actual_ppO2 < 90)
1940 CNS_fraction += time_factor/(-270.0 * char_I_actual_ppO2 + 35100.0);
1941 else if (char_I_actual_ppO2 < 110)
1942 CNS_fraction += time_factor/(-180.0 * char_I_actual_ppO2 + 27000.0);
1943 else if (char_I_actual_ppO2 < 150)
1944 CNS_fraction += time_factor/( -90.0 * char_I_actual_ppO2 + 17100.0);
1945 else if (char_I_actual_ppO2 < 160)
1946 CNS_fraction += time_factor/(-225.0 * char_I_actual_ppO2 + 37350.0);
1947 else if (char_I_actual_ppO2 < 165)
1948 CNS_fraction += time_factor*0.000755; // Arieli et all.(2002): Modeling pulmonary and CNS O2 toxicity... Formula (A1) based on value for 1.55 and c=20
1949 else if (char_I_actual_ppO2 < 170)
1950 CNS_fraction += time_factor*0.00102; // example calculation: Sqrt((1.7/1.55)^20)*0.000404
1951 else if (char_I_actual_ppO2 < 175)
1952 CNS_fraction += time_factor*0.00136;
1953 else if (char_I_actual_ppO2 < 180)
1954 CNS_fraction += time_factor*0.00180;
1955 else if (char_I_actual_ppO2 < 185)
1956 CNS_fraction += time_factor*0.00237;
1957 else if (char_I_actual_ppO2 < 190)
1958 CNS_fraction += time_factor*0.00310;
1959 else if (char_I_actual_ppO2 < 195)
1960 CNS_fraction += time_factor*0.00401;
1961 else if (char_I_actual_ppO2 < 200)
1962 CNS_fraction += time_factor*0.00517;
1963 else if (char_I_actual_ppO2 < 230)
1964 CNS_fraction += time_factor*0.0209;
1965 else
1966 CNS_fraction += time_factor*0.0482; // value for 2.5
1967
1968 if( CNS_fraction > 9.99)
1969 CNS_fraction = 9.99;
1970 if( CNS_fraction < 0.0 )
1971 CNS_fraction = 0.0;
1972
1973 int_O_CNS_fraction = (unsigned int)(100.0 * CNS_fraction + 0.5);
1974 }
1975
1976 //////////////////////////////////////////////////////////////////////////////
1977 // deco_calc_CNS_planning
1978 //
1979 // Compute CNS during predicted ascent.
1980 //
1981 // Note: Needs a call to deco_push_tissues_to_vault(),
1982 // deco_pull_tissues_from_vault() to avoid trashing everything...
1983 //
1984 // Input: CNS_fraction, char_O_deco_time[], char_O_deco_depth[]
1985 // Output: CNS_fraction, int_O_CNS_fraction
1986 //
1987 void deco_calc_CNS_planning(void)
1988 {
1989 overlay unsigned char backup_gas_last_depth;
1990 overlay unsigned char backup_gas_last_used;
1991 overlay unsigned short backup_dive_mins;
1992 overlay unsigned char backup_actual_ppO2;
1993
1994 RESET_C_STACK
1995
1996 // Backup state machine
1997 backup_gas_last_depth = sim_gas_last_depth;
1998 backup_gas_last_used = sim_gas_last_used;
1999 backup_dive_mins = sim_dive_mins;
2000 backup_actual_ppO2 = char_I_actual_ppO2;
2001
2002 // Uses 1min CNS period:
2003 char_I_step_is_1min = 1;
2004
2005 //---- Retrieve bottom Gas used, and set variables.
2006 sim_gas_last_used = char_I_first_gas;
2007 sim_gas_last_depth = 0; // Surface gas marker.
2008 gas_switch_set(); // Sets initial calc_N2/He_ratio
2009
2010 //---- CCR mode : do the full TTS at once --------------------------------
2011 if( char_I_const_ppO2 != 0 )
2012 {
2013 overlay unsigned short t; // Needs 16bits here !
2014 char_I_actual_ppO2 = char_I_const_ppO2;
2015 for(t=0; t<int_O_ascenttime; ++t)
2016 deco_calc_CNS_fraction();
2017 }
2018 else //---- OC mode : have to follow all gas switches... -----------------
2019 {
2020 overlay unsigned char i = 0; // Decostop loop counter
2021 overlay float actual_ppO2;
2022 overlay unsigned char time, t;
2023
2024 //---- Ascent to surface delay
2025 // NOTE: count as if time is spent with bottom pressure,
2026 // AND the bottom gas
2027 actual_ppO2 = (pres_surface + char_I_bottom_depth * METER_TO_BAR)
2028 * (1.0 - calc_N2_ratio - calc_He_ratio);
2029 if( actual_ppO2 < 0.0 ) actual_ppO2 = 0.0;
2030 if( actual_ppO2 > 2.50 ) actual_ppO2 = 2.55;
2031 char_I_actual_ppO2 = (unsigned char)(100.0 * actual_ppO2 + 0.5);
2032
2033 // Ascent time (rounded up):
2034 time = (unsigned char)(0.1 * char_I_bottom_depth + 0.5);
2035
2036 for(t=0; t<time; ++t)
2037 {
2038 deco_calc_CNS_fraction();
2039 sim_dive_mins++;
2040 }
2041
2042 //---- Do all further stops ------------------------------------------
2043 for(i=0; i<NUM_STOPS; ++i)
2044 {
2045 overlay unsigned char switch_gas;
2046
2047 //---- Get next stop, possibly in reverse order ------------------
2048 {
2049 time = char_O_deco_time[(NUM_STOPS-1)-i];
2050 temp_depth_limit = char_O_deco_depth[(NUM_STOPS-1)-i];
2051 }
2052 if( time == 0 ) continue;
2053
2054 //---- Gas Switch ? ----------------------------------------------
2055 switch_gas = temp_depth_limit & 0x80; // Switch flag.
2056 temp_depth_limit &= 0x7F; // True stop depth.
2057
2058 if( switch_gas )
2059 {
2060 gas_switch_deepest();
2061 gas_switch_set();
2062 }
2063
2064 //---- Convert Depth and N2_ratio to ppO2 ------------------------
2065 actual_ppO2 = (pres_surface + temp_depth_limit * METER_TO_BAR)
2066 * (1.0 - calc_N2_ratio - calc_He_ratio);
2067 if( actual_ppO2 < 0.0 ) actual_ppO2 = 0.0;
2068 if( actual_ppO2 > 2.50 ) actual_ppO2 = 2.55;
2069 char_I_actual_ppO2 = (unsigned char)(100.0 * actual_ppO2 + 0.5);
2070
2071 //---- Apply the stop
2072 for(t=0; t<time; ++t)
2073 {
2074 deco_calc_CNS_fraction();
2075 sim_dive_mins++;
2076 }
2077 }
2078 }
2079
2080 //---- Back to normal mode... --------------------------------------------
2081 char_I_step_is_1min = 0;
2082 sim_gas_last_depth = backup_gas_last_depth;
2083 sim_gas_last_used = backup_gas_last_used;
2084 sim_dive_mins = backup_dive_mins;
2085 char_I_actual_ppO2 = backup_actual_ppO2;
2086 }
2087
2088 //////////////////////////////////////////////////////////////////////////////
2089 // deco_calc_CNS_decrease_15min
2090 //
2091 // new in v.101
2092 //
2093 // calculates the half time of 90 minutes in 6 steps of 15 min
2094 // (Used in sleepmode, for low battery mode).
2095 //
2096 // Output: int_O_CNS_fraction
2097 // Uses and Updates: CNS_fraction
2098 //
2099 void deco_calc_CNS_decrease_15min(void)
2100 {
2101 RESET_C_STACK
2102 assert( 0.0 <= CNS_fraction && CNS_fraction <= 2.56 );
2103
2104 CNS_fraction = 0.890899 * CNS_fraction;
2105 int_O_CNS_fraction = (unsigned int)(CNS_fraction * 100.0 + 0.5);
2106 }
2107
2108 //////////////////////////////////////////////////////////////////////////////
2109 // deco_calc_percentage
2110 //
2111 // new in v.101
2112 //
2113 // calculates int_I_temp * char_I_temp / 100
2114 // output is int_I_temp
2115 //
2116 // Used to compute NoFly remaining time.
2117 //
2118 void deco_calc_percentage(void)
2119 {
2120 RESET_C_STACK
2121
2122 assert( 60 <= char_I_temp && char_I_temp <= 100 );
2123 assert( int_I_temp < 5760 ); // Less than 4 days = 96h...
2124
2125 int_I_temp = (unsigned short)(((float)int_I_temp * (float)char_I_temp) * 0.01 );
2126
2127 assert( int_I_temp < 5760 ); // Less than 96h too...
2128 }
2129
2130
2131 //////////////////////////////////////////////////////////////////////////////
2132 // deco_gas_volumes
2133 //
2134 // new in v.111
2135 //
2136 // calculates volumes for each gas.
2137 //
2138 // Input: char_I_bottom_depth, char_I_bottom_time for planned dive.
2139 // Gas list.
2140 // char_I_first_gas is the bottom gas.
2141 // decoplan (char_O_deco_depth, char_O_deco_time).
2142 // CF#54 == TRUE if shallowest stop first.
2143 // CF#56 == bottom liters/minutes (5 .. 50) or bar/min.
2144 // CF#57 == deco liters/minutes (5 .. 50) or bar/min.
2145 // Output: int_O_gas_volumes[0..4] in litters * 0.1
2146 //
2147 void deco_gas_volumes(void)
2148 {
2149 overlay float volumes[NUM_GAS];
2150 overlay float bottom_usage, deco_usage;
2151 overlay unsigned char i, deepest_first;
2152 overlay unsigned char gas, depth;
2153 RESET_C_STACK
2154
2155 //---- initialize with bottom consumption --------------------------------
2156 for(i=0; i<NUM_GAS; ++i) // Nothing yet...
2157 volumes[i] = 0.0;
2158
2159 assert(1 <= char_I_first_gas && char_I_first_gas <= NUM_GAS);
2160 gas = char_I_first_gas - 1;
2161
2162 bottom_usage = (float) char_I_bottom_usage;
2163 if( char_I_const_ppO2 == 0 && bottom_usage > 0.0 )
2164 volumes[gas]
2165 = (char_I_bottom_depth*0.1 + 1.0) // Use Psurface = 1.0 bar.
2166 * char_I_bottom_time // in minutes.
2167 * bottom_usage; // In liter/minutes.
2168
2169 //---- Ascent usage ------------------------------------------------------
2170 deco_usage = (float) char_I_deco_usage; // In liter/minutes.
2171
2172 depth = char_I_bottom_depth;
2173
2174 for(i=0; i<NUM_STOPS; ++i)
2175 {
2176 overlay unsigned char newDepth, time;
2177
2178 // Manage stops in reverse order (CF#54)
2179 if( deepest_first )
2180 {
2181 time = char_O_deco_time[i];
2182 if( time == 0 ) break; // End of table: done.
2183
2184 newDepth = char_O_deco_depth[i] & 0x7F;
2185 }
2186 else
2187 {
2188 time = char_O_deco_time[31-i];
2189 if( time == 0 ) continue; // not yet: still search table.
2190
2191 newDepth = char_O_deco_depth[31-i] & 0x7F;
2192 }
2193
2194 //---- Gas switch during this step -----------------------------------
2195 {
2196 overlay unsigned char newGas = 0;
2197 overlay unsigned char newStop = 0; // NO CHANGE yet
2198 overlay unsigned char j;
2199
2200 for(j=0; j<NUM_GAS; ++j)
2201 {
2202 // Skip gas without changing depth:
2203 if( ! char_I_deco_gas_change[j] )
2204 continue;
2205 // Select gas changed between [newDepth .. depth]
2206 if( newDepth <= char_I_deco_gas_change[j]
2207 && char_I_deco_gas_change[j] <= depth )
2208 {
2209 // Keep the DEEPEST gas in that range:
2210 // Note: that = means changing gas at BEGINNING of this stop.
2211 if( char_I_deco_gas_change[j] >= newStop )
2212 {
2213 newGas = j;
2214 newStop = char_I_deco_gas_change[j];
2215 }
2216 }
2217 }
2218
2219 if( newStop ) // Did we find something ?
2220 {
2221 // usage BEFORE gas switch (if any), at 10m/min :
2222 if( deco_usage > 0.0 && depth > newStop )
2223 // Plus usage during ascent to the next stop, at 10m/min.
2224 volumes[gas] += ((depth+newStop)*0.05 + 1.0) // average depth --> bar.
2225 * (depth-newStop)*0.1 // metre --> min
2226 * deco_usage;
2227
2228 // Do gas switch:
2229 gas = newGas;
2230 depth = newStop;
2231 }
2232 }
2233
2234 // usage AFTER gas switch (if any), at 10m/min :
2235 if( depth > newDepth )
2236 volumes[gas] += ((depth+newDepth)*0.05 + 1.0) // average depth --> bar.
2237 * (depth-newDepth)*0.1 // metre --> min
2238 * deco_usage;
2239
2240 // Do stop:
2241 depth = newDepth;
2242
2243 // Usage at stop:
2244 if( deco_usage > 0.0 )
2245 volumes[gas] += (depth*0.1 + 1.0) // depth --> bar.
2246 * time // in minutes.
2247 * deco_usage; // in xxx / min @ 1bar.
2248 else
2249 volumes[gas] = 65535.0;
2250 }
2251
2252 // From last stop to surface
2253 if( deco_usage > 0.0 )
2254 volumes[gas] += (depth*0.05 + 1.0) // avg depth --> bar.
2255 * depth * 0.1 // time to surface, in minutes.
2256 * deco_usage; // in xxx / min @ 1bar.
2257
2258 //---- convert results for the ASM interface -----------------------------
2259 for(i=0; i<NUM_GAS; ++i)
2260 if( volumes[i] > 65534.0 )
2261 int_O_gas_volumes[i] = 65535;
2262 else
2263 int_O_gas_volumes[i] = (unsigned short)(volumes[i] + 0.5);
2264 }
2265
2266 //////////////////////////////////////////////////////////////////////////////
2267
2268 void deco_push_tissues_to_vault(void)
2269 {
2270 overlay unsigned char x;
2271 RESET_C_STACK
2272
2273 cns_vault = CNS_fraction;
2274 low_depth_vault = low_depth;
2275
2276 for (x=0;x<NUM_COMP;x++)
2277 {
2278 pres_tissue_N2_vault[x] = pres_tissue_N2[x];
2279 pres_tissue_He_vault[x] = pres_tissue_He[x];
2280 }
2281 }
2282
2283 void deco_pull_tissues_from_vault(void)
2284 {
2285 overlay unsigned char x;
2286 RESET_C_STACK
2287
2288 for (x=0; x<NUM_COMP; x++)
2289 {
2290 pres_tissue_N2[x] = pres_tissue_N2_vault[x];
2291 pres_tissue_He[x] = pres_tissue_He_vault[x];
2292 }
2293
2294 // Restore both CNS variable, too.
2295 CNS_fraction = cns_vault;
2296 int_O_CNS_fraction = (unsigned int)(CNS_fraction * 100.0 + 0.5);
2297
2298 // GF history too:
2299 low_depth = low_depth_vault;
2300 locked_GF_step = GF_delta / low_depth;
2301 }
2302
2303 //////////////////////////////////////////////////////////////////////////////
2304 //
2305 #ifndef CROSS_COMPILE
2306 void main() {}
2307 #endif