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comparison src/adc_lightsensor.asm @ 643:7d8a4c60ec1a

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3.15 release
author heinrichsweikamp
date Mon, 24 May 2021 18:40:53 +0200
parents 8c1f1f334275
children 070528a88715 357341239438
comparison
equal deleted inserted replaced
642:a9a0188091e4 643:7d8a4c60ec1a
23 ;----------------------------------------------------------------------------- 23 ;-----------------------------------------------------------------------------
24 ; Helper Function - wait on ADC to finish conversion 24 ; Helper Function - wait on ADC to finish conversion
25 ; 25 ;
26 ; bank safe 26 ; bank safe
27 ; 27 ;
28 global wait_adc
28 wait_adc: 29 wait_adc:
29 movwf ADCON0 ; select ADC channel 30 movwf ADCON0 ; select ADC channel
30 nop ; wait a short moment 31 nop ; wait a short moment
31 nop ; ... 32 nop ; ...
32 nop ; ..... 33 nop ; .....
276 banksel isr_backup ; back to ISR default bank 277 banksel isr_backup ; back to ISR default bank
277 clrf ADCON1 ; Vref+ = Vdd 278 clrf ADCON1 ; Vref+ = Vdd
278 movlw b'00011101' ; power on ADC, select AN7 279 movlw b'00011101' ; power on ADC, select AN7
279 rcall wait_adc 280 rcall wait_adc
280 MOVII ADRESL,ambient_light 281 MOVII ADRESL,ambient_light
281 bcf ADCON0,0 ; power off ADC 282 bcf ADCON0,0 ; power off ADC
282 283
284 btfsc ambient_light+1,7 ; result negative?
285 return ; Yes, skip this measurement
283 ; ambient_light:2 is between 4096 (direct sunlight) and about 200 (darkness) 286 ; ambient_light:2 is between 4096 (direct sunlight) and about 200 (darkness)
284 ; first: divide by 16 287 ; first: divide by 16
285
286 movlw .4 ; divide by 2^4 = 16 288 movlw .4 ; divide by 2^4 = 16
287 get_ambient_level1_loop: 289 get_ambient_level1_loop:
288 bcf STATUS,C ; clear carry 290 bcf STATUS,C ; clear carry
289 rrcf ambient_light+1 ; rotate right high byte, carry into MSB, LSB into carry 291 rrcf ambient_light+1 ; rotate right high byte, carry into MSB, LSB into carry
290 rrcf ambient_light+0 ; rotate right low byte, carry into MSB, LSB into carry 292 rrcf ambient_light+0 ; rotate right low byte, carry into MSB, LSB into carry
297 movlw .254 299 movlw .254
298 tstfsz ambient_light+1 ; > 255 ? 300 tstfsz ambient_light+1 ; > 255 ?
299 movwf ambient_light+0 ; YES - avoid ADC clipping 301 movwf ambient_light+0 ; YES - avoid ADC clipping
300 302
301 incfsz ambient_light+0,W ; = 255 ? 303 incfsz ambient_light+0,W ; = 255 ?
302 bra get_ambient_level2 ; NO - continue 304 bra get_ambient_level2 ; NO - continue
303 305
304 movlw .254 306 movlw .254
305 movwf ambient_light+0 ; avoid ADC clipping 307 movwf ambient_light+0 ; avoid ADC clipping
306 308
307 get_ambient_level2: 309 get_ambient_level2: