ESP32-PaxCounter/src/battery.cpp
2018-07-15 14:28:05 +02:00

54 lines
1.6 KiB
C++

#ifdef HAS_BATTERY_PROBE
#include "globals.h"
// Local logging tag
static const char TAG[] = "main";
static void print_char_val_type(esp_adc_cal_value_t val_type) {
if (val_type == ESP_ADC_CAL_VAL_EFUSE_TP) {
ESP_LOGI(TAG,
"ADC characterization based on Two Point values stored in eFuse");
} else if (val_type == ESP_ADC_CAL_VAL_EFUSE_VREF) {
ESP_LOGI(TAG,
"ADC characterization based on reference voltage stored in eFuse");
} else {
ESP_LOGI(TAG, "ADC characterization based on default reference voltage");
}
}
uint16_t read_voltage(void) {
static const adc1_channel_t channel = HAS_BATTERY_PROBE;
static const adc_atten_t atten = ADC_ATTEN_DB_11;
static const adc_unit_t unit = ADC_UNIT_1;
// configure ADC1
ESP_ERROR_CHECK(adc1_config_width(ADC_WIDTH_BIT_12));
ESP_ERROR_CHECK(adc1_config_channel_atten(channel, atten));
// calibrate ADC1
esp_adc_cal_characteristics_t *adc_chars =
(esp_adc_cal_characteristics_t *)calloc(
1, sizeof(esp_adc_cal_characteristics_t));
esp_adc_cal_value_t val_type = esp_adc_cal_characterize(
unit, atten, ADC_WIDTH_BIT_12, DEFAULT_VREF, adc_chars);
print_char_val_type(val_type);
// multisample ADC1
uint32_t adc_reading = 0;
for (int i = 0; i < NO_OF_SAMPLES; i++) {
adc_reading += adc1_get_raw(channel);
}
adc_reading /= NO_OF_SAMPLES;
// Convert adc_reading to voltage in mV
uint16_t voltage =
(uint16_t)esp_adc_cal_raw_to_voltage(adc_reading, adc_chars);
#ifdef BATT_FACTOR
voltage *= BATT_FACTOR;
#endif
ESP_LOGI(TAG, "Raw: %d / Voltage: %dmV", adc_reading, voltage);
return voltage;
}
#endif // HAS_BATTERY_PROBE