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#include "battery.hpp"
#include "driver/adc.h"
#include "esp_adc_cal.h"
#include "hal/adc_types.h"
namespace drivers {
static esp_adc_cal_characteristics_t calibration;
esp_err_t init_adc(void) {
// Calibration should already be fused into the chip from the factory, so
// we should only need to read it back out again.
esp_adc_cal_characterize(ADC_UNIT_1, ADC_ATTEN_DB_11, ADC_WIDTH_BIT_12, 0,
&calibration);
// Max battery voltage should be a little over 2V due to our divider, so
// we need the max attenuation to properly handle the full range.
adc1_config_width(ADC_WIDTH_BIT_12);
adc1_config_channel_atten(ADC1_CHANNEL_6, ADC_ATTEN_DB_11);
return ESP_OK;
}
uint32_t read_battery_voltage(void) {
// GPIO 34
int raw = adc1_get_raw(ADC1_CHANNEL_6);
return esp_adc_cal_raw_to_voltage(raw, &calibration);
}
} // namespace drivers
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