esp32_adc_channel.hpp

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#ifndef ESP32_ADC_CHANNEL_HPP__
#define ESP32_ADC_CHANNEL_HPP__
 
#include <array>
 
#include "driver/gpio.h"
#include "driver/timer.h"
#include "driver/adc.h"
#include "esp_adc_cal.h"
#include "soc/sens_reg.h"
#include "soc/sens_struct.h"
 
#include "adc_filter_interpolation.hpp"
#include "app_config.hpp"
 
 
class ESP32ADCChannel
{
public:
    adc1_channel_t channel_num;
    adc_atten_t attenuation;
    esp_adc_cal_characteristics_t calibration_data;
 
    ESP32ADCChannel(adc1_channel_t channel_num,
                    adc_atten_t attenuation,
                    uint32_t averaged_samples = 64,
                    adc_bits_width_t bits_width = ADC_WIDTH_BIT_12,
                    uint32_t default_vref = 1100u);
 
    uint16_t get_raw_averaged();
 
    uint16_t get_voltage_averaged();
 
    int32_t calculate_raw_from_voltage(uint32_t v_in_mv);
 
    void debug_print_check_efuse();
    void debug_print_characterisation_val_type(esp_adc_cal_value_t val_type);
    void test_register_direct();
 
protected:
    uint32_t division_shift;
    // Initialised with an invalid value to check if HW was initialised by a
    // previous constructor call. (All channels must have same bits_width)
    inline static auto _bits_width = adc_bits_width_t{ADC_WIDTH_MAX};
};
 
 
template<size_t filter_length>
class ESP32ADCChannelFiltered : public ESP32ADCChannel
{
public:
    ESP32ADCChannelFiltered(adc1_channel_t channel_num,
                            adc_atten_t attenuation,
                            uint32_t averaged_samples = 64,
                            adc_bits_width_t bits_width = ADC_WIDTH_BIT_12,
                            uint32_t default_vref = 1100u)
        : ESP32ADCChannel{channel_num, attenuation, averaged_samples,
                          bits_width, default_vref}
    {
        filter.initialize(get_raw_averaged());
    }
 
    void trigger_acquisition() {
        auto raw_sample = get_raw_averaged();
        filter.input_data(raw_sample);
    }
 
    uint16_t get_raw_filtered(bool trigger_new_acquisition = true) {
        if (trigger_new_acquisition) {
            trigger_acquisition();
        }
        return filter.get_result();
    }
 
 
    uint16_t get_voltage_filtered(bool trigger_new_acquisition = true) {
        return esp_adc_cal_raw_to_voltage(get_raw_filtered(trigger_new_acquisition),
                                          &calibration_data);
    }
 
protected:
    MovingAverageUInt16<filter_length> filter;
};
 
#endif