ESP32ADCChannel Class Reference

ESP32 ADC 1 channel access with configurable averaging. More...

#include <esp32_adc_channel.hpp>

Inheritance diagram for ESP32ADCChannel:

Public Member Functions
	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)
	Initialize an ESP32 ADC channel. More...
uint16_t	get_raw_averaged ()
	Get raw ADC channel conversion value. Repeats sampling a number of times, see "averaged_samples" constructor parameter. More...
uint16_t	get_voltage_averaged ()
	Get channel input voltage in millivolts. Repeats sampling a number of times, see "averaged_samples" constructor parameter. More...
int32_t	calculate_raw_from_voltage (uint32_t v_in_mv)
	Calculate backwards the raw ADC reading for given input voltage, based on calibration constants from ADC initialisation, and also based on a ADC resolution setting of 12 bits.
void	debug_print_check_efuse ()
void	debug_print_characterisation_val_type (esp_adc_cal_value_t val_type)
void	test_register_direct ()

Public Attributes
adc1_channel_t	channel_num
adc_atten_t	attenuation
esp_adc_cal_characteristics_t	calibration_data

Protected Attributes
uint32_t	division_shift

Static Protected Attributes
static auto	_bits_width = adc_bits_width_t{ADC_WIDTH_MAX}

Detailed Description

ESP32 ADC 1 channel access with configurable averaging.

Input voltage can be read raw or as calibrated voltage value in millivolts.

Raw output is always scaled such as if the ADC was set to 12 bits mode, i.e. theoretical full-scale output is 4096 - 1

Note

For additional moving average filtering and smoothing, please see the additional templated version in class ESP32ADCChannelFiltered.

Constructor & Destructor Documentation

ESP32ADCChannel()

ESP32ADCChannel::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
	)

Initialize an ESP32 ADC channel.

Parameters

channel_num	Analog input channel number
attenuation	Voltage input scale setting, see ESP-IDF reference
averaged_samples	Read this many input samples at once for any trigger
bits_width	Can be less then ADC_WIDTH_BIT_12 for faster speed.

Note

The "bits_width" setting must be identical for all channels!

Parameters

default_vref

Can be manually set if hardware has no e-fuse calibration

Member Function Documentation

debug_print_check_efuse()

void ESP32ADCChannel::debug_print_check_efuse

(

)

Debug functions

get_raw_averaged()

uint16_t ESP32ADCChannel::get_raw_averaged

(

)

Get raw ADC channel conversion value. Repeats sampling a number of times, see "averaged_samples" constructor parameter.

The output is always scaled such as if the ADC was set to 12 bits mode, i.e. theoretical full-scale output is 4096 - 1

get_voltage_averaged()

uint16_t ESP32ADCChannel::get_voltage_averaged

(

)

Get channel input voltage in millivolts. Repeats sampling a number of times, see "averaged_samples" constructor parameter.

This takes into account the calibration constants from ADC initialisation. If there is no e-fuse calibration on-chip, this uses the default_vref setting from the constructor, default is 1100 millivolts.

Returns

Voltage in millivolts

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The documentation for this class was generated from the following files:

• main/include/esp32_adc_channel.hpp
• main/esp32_adc_channel.cpp