Mercurial > public > ostc4
view Small_CPU/Src/batteryGasGauge.c @ 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 | f9ba924d188e |
line wrap: on
line source
/** ****************************************************************************** * @file batteryGasGauge.c * @author heinrichs weikamp gmbh * @version V0.0.1 * @date 09-Dec-2014 * @brief LTC2942 Battery Gas Gauge * @verbatim ============================================================================== ##### stm32f4xx_hal_i2c.c modification ##### ============================================================================== The LTC2942 requires an repeated start condition without stop condition for data reception. @endverbatim ****************************************************************************** * @attention * * <h2><center>© COPYRIGHT(c) 2014 heinrichs weikamp</center></h2> * ****************************************************************************** */ /* Includes ------------------------------------------------------------------*/ #include "batteryGasGauge.h" #include "baseCPU2.h" #include "stm32f4xx_hal.h" #include "i2c.h" float battery_f_voltage = 0; float battery_f_charge_percent = 0; #define BGG_BATTERY_OFFSET (26123) //; 65536-(3,35Ah/0,085mAh) #define BGG_BATTERY_DEVIDER (394) //; 3,35Ah/0,085mAh/100 [%] float get_voltage(void) { #ifdef OSTC_ON_DISCOVERY_HARDWARE return 3.0f; #endif return battery_f_voltage; } float get_charge(void) { #ifdef OSTC_ON_DISCOVERY_HARDWARE return 100.0f; #endif return battery_f_charge_percent; } void init_battery_gas_gauge(void) { #ifdef OSTC_ON_DISCOVERY_HARDWARE return; #endif uint8_t buffer[2]; buffer[0] = 0x01; buffer[1] = 0xF8;// true: F8 = 11111000, wrong/old comment: 11101000 I2C_Master_Transmit( DEVICE_BATTERYGAUGE, buffer, 2); } void battery_gas_gauge_get_data(void) { #ifdef OSTC_ON_DISCOVERY_HARDWARE return; #endif float battery_f_voltage_local; float battery_f_charge_percent_local; uint8_t bufferReceive[10]; I2C_Master_Receive( DEVICE_BATTERYGAUGE, bufferReceive, 10); battery_f_voltage_local = (float)(bufferReceive[8] * 256); battery_f_voltage_local += (float)(bufferReceive[9]); battery_f_voltage_local *= (float)6 / (float)0xFFFF; // max/full: 0.085 mAh * 1 * 65535 = 5570 mAh battery_f_charge_percent_local = (float)(bufferReceive[2] * 256); battery_f_charge_percent_local += (float)(bufferReceive[3]); battery_f_charge_percent_local -= BGG_BATTERY_OFFSET; battery_f_charge_percent_local /= BGG_BATTERY_DEVIDER; if(battery_f_charge_percent_local < 0) battery_f_charge_percent_local = 0; battery_f_voltage = battery_f_voltage_local; battery_f_charge_percent = battery_f_charge_percent_local; } void battery_gas_gauge_set_charge_full(void) { #ifdef OSTC_ON_DISCOVERY_HARDWARE return; #endif uint8_t bufferSend[3]; bufferSend[0] = 0x02; bufferSend[1] = 0xFF; bufferSend[2] = 0xFF; I2C_Master_Transmit( DEVICE_BATTERYGAUGE, bufferSend, 3); } void battery_gas_gauge_set(float percentage) { #ifdef OSTC_ON_DISCOVERY_HARDWARE return; #endif uint16_t mAhSend; if(percentage >= 100) mAhSend = 0xFFFF; else mAhSend = (uint16_t)(percentage * 655.35f); uint8_t bufferSend[3]; bufferSend[0] = 0x02; bufferSend[1] = (uint8_t)(mAhSend / 256); bufferSend[2] = (uint8_t)(mAhSend & 0xFF); I2C_Master_Transmit( DEVICE_BATTERYGAUGE, bufferSend, 3); } /************************ (C) COPYRIGHT heinrichs weikamp *****END OF FILE****/