kbf/src/adc.cpp

#include "kbf/adc.h"

#include <esp_log.h>

#include "kbf/macros.h"

using namespace kbf;

adc::ADC1::ADC1(int channel) : channel(static_cast<adc1_channel_t>(channel)) {
    ESP_LOGI(TAG, "configuring ADC1 channel %d", channel);
    CHECK(adc1_config_width(KBF_ADC_WIDTH));
    CHECK(adc1_config_channel_atten(this->channel, KBF_ADC_ATTEN));

    adcChars = new esp_adc_cal_characteristics_t();
    auto cal = esp_adc_cal_characterize(ADC_UNIT_1, KBF_ADC_ATTEN, KBF_ADC_WIDTH, KBF_ADC_DEFAULT_VREF, adcChars);

    switch (cal) {
        case ESP_ADC_CAL_VAL_EFUSE_VREF:
            ESP_LOGI(TAG, "characterized using eFuse Vref");
            break;
        case ESP_ADC_CAL_VAL_EFUSE_TP:
            ESP_LOGI(TAG, "characterized using eFuse two point value");
            break;
        case ESP_ADC_CAL_VAL_DEFAULT_VREF:
            ESP_LOGW(TAG, "characterized using default Vref");
            break;
        default:
            ESP_LOGE(TAG, "unexpected response from esp_adc_cal_characterize: %d", cal);
            ABORT("debug me");
    }
}

uint32_t adc::ADC1::readRaw() const {
    int reading = 0;
    for (int i = 0; i < KBF_ADC_NUM_SAMPLES; i++) {
        reading += adc1_get_raw(channel);
    }
    reading /= KBF_ADC_NUM_SAMPLES;
    return reading;
}

uint32_t adc::ADC1::readVoltage() const {
    uint32_t reading = 0;
    for (int i = 0; i < KBF_ADC_NUM_SAMPLES; i++) {
        uint32_t voltage = 0;
        CHECK(esp_adc_cal_get_voltage((adc_channel_t) channel, adcChars, &voltage));
        reading += voltage;
    }
    reading /= KBF_ADC_NUM_SAMPLES;
    return reading;
}

uint32_t adc::ADC1::rawToVoltage(int raw) const {
    return esp_adc_cal_raw_to_voltage(raw, adcChars);
}