void calibrate_opamp_offset_trim(settings_t *newsettings, int microamps, progress_callback_t progress_callback) {
state.calibrating = 1;
int high_value = microamps / DEFAULT_DAC_HIGH_GAIN;
int low_value = 100000 / DEFAULT_DAC_HIGH_GAIN; // Approx 100mA
int high_current, low_current;
IDAC_Low_SetValue(0);
// Find the best setting for the opamp trim
int min_offset = INT_MIN;
int min_offset_idx = 0;
for(int i = 0; i < MAX_OA_OFFSET_STEPS; i++) {
progress_callback(i+1,MAX_OA_OFFSET_STEPS);
CY_SET_REG32(Opamp_cy_psoc4_abuf__OA_OFFSET_TRIM, i);
IDAC_High_SetValue(high_value);
vTaskDelay(configTICK_RATE_HZ);
high_current = get_raw_current_usage() - newsettings->calibration_settings.adc_current_offset;
IDAC_High_SetValue(low_value);
vTaskDelay(configTICK_RATE_HZ);
low_current = get_raw_current_usage() - newsettings->calibration_settings.adc_current_offset;
int offset = (high_value * low_current - low_value * high_current) / (high_value - low_value);
if(offset <= 0 && offset > min_offset) {
min_offset = offset;
min_offset_idx = i;
}
}
set_opamp_offset_trim(newsettings, min_offset_idx);
set_current(0);
state.calibrating = 0;
}
void calibrate_dacs(settings_t *newsettings, int microamps) {
state.calibrating = 1;
int high_value = microamps / DEFAULT_DAC_HIGH_GAIN;
int low_value = 100000 / DEFAULT_DAC_HIGH_GAIN; // Approx 100mA
int high_current, low_current;
IDAC_Low_SetValue(0);
// Calculate offset and gain for IDAC_High
IDAC_High_SetValue(high_value);
vTaskDelay(configTICK_RATE_HZ * 2);
high_current = (get_raw_current_usage() - newsettings->calibration_settings.adc_current_offset) * settings->calibration_settings.adc_current_gain;
IDAC_High_SetValue(low_value);
vTaskDelay(configTICK_RATE_HZ * 2);
low_current = (get_raw_current_usage() - newsettings->calibration_settings.adc_current_offset) * settings->calibration_settings.adc_current_gain;
newsettings->calibration_settings.dac_high_gain = (high_current - low_current) / (high_value - low_value);
newsettings->calibration_settings.dac_offset = high_current - high_value * newsettings->calibration_settings.dac_high_gain;
// Calculate gain for IDAC_Low
IDAC_Low_SetValue(127);
vTaskDelay(configTICK_RATE_HZ * 4);
newsettings->calibration_settings.dac_low_gain = ((get_raw_current_usage() - newsettings->calibration_settings.adc_current_offset) * settings->calibration_settings.adc_current_gain - low_current) / 127;
// Reset for 0 output
set_current(0);
state.calibrating = 0;
}
void set_current(int setpoint) {
if(setpoint < 0)
setpoint = 0;
state.current_setpoint = setpoint;
setpoint -= settings->dac_offset;
setpoint -= get_dac_offset_correction();
if(setpoint < 0)
setpoint = 0;
IDAC_High_SetValue(setpoint / settings->dac_high_gain);
IDAC_Low_SetValue((setpoint % settings->dac_high_gain) / settings->dac_low_gain);
}