annotate Small_CPU/Inc/pressure.h @ 224:ceecabfddb57
div-fixes-3
Bugfix, deco: fix 2 (small) problems with calculated ceiling
This fixes 1 trivial, and 1 not really trivial bug in the calculation
of the ceiling. When simulating a bounce dive to 80m, things become
clear (tried this on a CCR dive, fixed setpoint 1.2bar, about 15 minutes
of bottom time). Closely watch the behavior of the ceiling data. At some
point during the ascent, the ceiling begins to decrease in 10cm steps.
Then suddenly (while still ascending), the ceiling increases again with 1m,
does not change for some time, and then suddenly steps 1.1m less deep.
While not very relevant to real deco diving, it is simply wrong.
The reason for this is subtle. The algorithm used to find the ceiling
is a sort of linear search, stepping down a meter, overshoot the depth, and
search back in 10cm steps. It seems some numerical instability. Fixing
this, was a bit more computational intensive search by stepping up down in
equal steps of 10cm. But, I'm pretty sure that things can be speeded up here, as a
ceiling does not change fast, so it should be not that difficult to limit
the search space, or use a binary search algorithm instead.
The trivial second problem fixed, is that the ceiling ends at the surface
and not at 1m depth. This small issue became visible after changing the step
down size above.
Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>
| author |
Jan Mulder <jlmulder@xs4all.nl> |
| date |
Sun, 31 Mar 2019 19:35:51 +0200 |
| parents |
5f11787b4f42 |
| children |
8e9c502c0b06 |
| rev |
line source |
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38
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1 /* Define to prevent recursive inclusion -------------------------------------*/
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2 #ifndef PRESSURE_H
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3 #define PRESSURE_H
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4
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5 #include <stdint.h>
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6
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7 uint8_t init_pressure(void);
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8 uint8_t pressure_update(void);
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9
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10 uint8_t is_init_pressure_done(void);
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11
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12 void pressure_sensor_get_pressure_raw(void);
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13 void pressure_sensor_get_temperature_raw(void);
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14 void pressure_calculation(void);
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15
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16 float get_temperature(void);
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17 float get_pressure_mbar(void);
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18 float get_surface_mbar(void);
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19
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20 void init_surface_ring(void);
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21 void update_surface_pressure(uint8_t call_rhythm_seconds);
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22
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23 uint32_t demo_modify_temperature_and_pressure(int32_t divetime_in_seconds, uint8_t subseconds, float ceiling_mbar);
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24
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25 #endif /* PRESSURE_H */
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26
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