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view Small_CPU/Inc/compass_LSM303DLHC.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 |
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/** ****************************************************************************** * @file compass_LSM303DLHC.h * @author heinrichs weikamp gmbh * @date 17-August-2017 * @version V0.1.0 * @since 17-August-2017 * @brief STMicroelectronics LSM303DLHC accelerometer & magnetometer driver * @verbatim ============================================================================== ##### How to use ##### ============================================================================== @endverbatim ****************************************************************************** * @attention * * <h2><center>© COPYRIGHT(c) 2017 heinrichs weikamp</center></h2> * ****************************************************************************** */ /* Define to prevent recursive inclusion -------------------------------------*/ #ifndef COMPASS_LSM303DLHC_H #define COMPASS_LSM303DLHC_H /* Exported constants --------------------------------------------------------*/ //#include "compass_LSM303D.h" #define DLHC_CTRL_REG1_A 0x20 #define DLHC_CTRL_REG2_A 0x21 #define DLHC_CTRL_REG3_A 0x22 #define DLHC_CTRL_REG4_A 0x23 #define DLHC_CTRL_REG5_A 0x24 #define DLHC_CTRL_REG6_A 0x25 #define DLHC_CRA_REG_M 0x00 #define DLHC_CRB_REG_M 0x01 #define DLHC_MR_REG_M 0x02 #define DLHC_OUT_X_L_M 0x03 #define DLHC_OUT_X_H_M 0x04 #define DLHC_OUT_Y_L_M 0x05 #define DLHC_OUT_Y_H_M 0x06 #define DLHC_OUT_Z_L_M 0x07 #define DLHC_OUT_Z_H_M 0x08 // identisch mit 303D #define DLHC_OUT_X_L_A 0x28 #define DLHC_OUT_X_H_A 0x29 #define DLHC_OUT_Y_L_A 0x2A #define DLHC_OUT_Y_H_A 0x2B #define DLHC_OUT_Z_L_A 0x2C #define DLHC_OUT_Z_H_A 0x2D #endif /* COMPASS_LSM303DLHC_H */ /******************* (C) COPYRIGHT 2017 heinrichs weikamp *****END OF FILE****/