ESP32 ADC type definitions for hardware abstraction. More...

#include "BaseAdc.h"
#include "EspTypes_Base.h"
#include "HardwareTypes.h"
#include "McuSelect.h"
#include <esp_adc/adc_continuous.h>
#include <esp_adc/adc_oneshot.h>

Include dependency graph for EspTypes_ADC.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Classes
struct	hf_adc_channel_config_t
	ADC channel configuration structure. More...

struct	hf_adc_continuous_config_t
	ADC continuous mode configuration structure. More...

struct	hf_adc_filter_config_t
	ADC filter configuration structure. More...

struct	hf_adc_monitor_config_t
	ADC monitor configuration structure. More...

struct	hf_adc_calibration_config_t
	ADC calibration configuration structure. More...

struct	hf_adc_unit_config_t
	ADC unit configuration structure. More...

struct	hf_adc_continuous_data_t
	ADC continuous data structure. More...

struct	hf_adc_monitor_event_t
	ADC monitor event structure. More...

Typedefs
using	hf_adc_continuous_callback_t
	ADC continuous mode data callback function.

using	hf_adc_monitor_callback_t = void ()(const hf_adc_monitor_event_t event, void* user_data)
	ADC threshold monitor callback function.

Enumerations
enum class	hf_adc_mode_t : uint8_t { ONESHOT = 0 , CONTINUOUS = 1 }
	ADC operating modes supported by ESP32. More...

enum class	hf_adc_atten_t : uint8_t { ATTEN_DB_0 = ADC_ATTEN_DB_0 , ATTEN_DB_2_5 = ADC_ATTEN_DB_2_5 , ATTEN_DB_6 = ADC_ATTEN_DB_6 , ATTEN_DB_12 = ADC_ATTEN_DB_12 }
	ADC attenuation levels for ESP32 These control the input voltage range that can be measured Values must match ESP-IDF adc_atten_t enum. More...

enum class	hf_adc_bitwidth_t : uint8_t { WIDTH_9BIT = ADC_BITWIDTH_9 , WIDTH_10BIT = ADC_BITWIDTH_10 , WIDTH_11BIT = ADC_BITWIDTH_11 , WIDTH_12BIT = ADC_BITWIDTH_12 , WIDTH_13BIT = ADC_BITWIDTH_13 , WIDTH_DEFAULT = ADC_BITWIDTH_DEFAULT }
	ADC resolution/bit width settings for ESP32 Values must match ESP-IDF adc_bitwidth_t enum. More...

enum class	hf_adc_filter_coeff_t : uint8_t { COEFF_2 = 0 , COEFF_4 = 1 , COEFF_8 = 2 , COEFF_16 = 3 , COEFF_64 = 4 }
	ADC filter coefficient enumeration. More...

enum class	hf_adc_monitor_event_type_t : uint8_t { HIGH_THRESH = 0 , LOW_THRESH = 1 }
	ADC monitor event type enumeration. More...

Functions
constexpr uint32_t	CalcFrameSize (uint32_t samples_per_frame, uint32_t enabled_channels) noexcept
	Calculate frame size in bytes based on samples per frame and enabled channels.

constexpr uint32_t	CalcBufferPoolSize (uint32_t samples_per_frame, uint32_t enabled_channels, uint32_t max_store_frames) noexcept
	Calculate total buffer pool size based on frames and enabled channels.

constexpr bool	IsValidContinuousConfig (uint32_t samples_per_frame, uint32_t enabled_channels, uint32_t max_store_frames) noexcept
	Validate continuous mode configuration parameters.

constexpr bool	IsValidFrameSize (uint32_t frame_size) noexcept
	Validate that frame size is properly aligned.

constexpr uint32_t	GetFrameResultCount (uint32_t frame_size) noexcept
	Calculate number of conversion results that fit in a frame.

constexpr hf_channel_id_t	GpioToAdcChannel (hf_pin_num_t gpio_pin) noexcept
	Convert GPIO pin to ADC channel for ESP32.

constexpr hf_pin_num_t	AdcChannelToGpio (hf_channel_id_t channel_id) noexcept
	Convert ADC channel to GPIO pin for ESP32.

constexpr uint32_t	GetMaxInputVoltage (hf_adc_atten_t atten) noexcept
	Get maximum input voltage for given attenuation.

constexpr uint32_t	GetMaxRawValue (hf_adc_bitwidth_t bitwidth) noexcept
	Get maximum raw value for given bit width.

Variables
constexpr uint32_t	HF_ESP32_ADC_DATA_BYTES_PER_CONV
	Example of ISR-safe ADC callback implementation.

constexpr uint32_t	HF_ESP32_ADC_MIN_FRAME_SIZE = 64
	Minimum frame size.

constexpr uint32_t	HF_ESP32_ADC_MAX_FRAME_SIZE = 1024
	Maximum frame size.

constexpr uint32_t	HF_ESP32_ADC_DEFAULT_FRAME_SIZE = 256
	Default frame size.

Detailed Description

ESP32 ADC type definitions for hardware abstraction.

This header defines only the essential ADC-specific types and constants used by the EspAdc implementation. It follows a clean, minimal pattern providing only necessary types without redundant or duplicate definitions.

Author: Nebiyu Tadesse

Date: 2025

Copyright: HardFOC

Typedef Documentation

◆ hf_adc_continuous_callback_t

using hf_adc_continuous_callback_t

Initial value:

bool (*)(const hf_adc_continuous_data_t* data,

void* user_data)

hf_adc_continuous_data_t

ADC continuous data structure.

Definition EspTypes_ADC.h:176

ADC continuous mode data callback function.

Warning

This callback is executed in ISR context and must be ISR-safe:

Use only ISR-safe functions (no malloc, free, printf, etc.)
Keep execution time as short as possible
Avoid calling blocking functions or FreeRTOS APIs that are not ISR-safe
Use only stack variables or pre-allocated memory
Consider using xQueueSendFromISR() or similar to defer processing

Parameters

data	Continuous data structure containing sampled data
user_data	User-provided data pointer

Returns: true to yield to higher priority task, false to continue

◆ hf_adc_monitor_callback_t

using hf_adc_monitor_callback_t = void (*)(const hf_adc_monitor_event_t* event, void* user_data)

ADC threshold monitor callback function.

Warning

This callback is executed in ISR context and must be ISR-safe:

Use only ISR-safe functions (no malloc, free, printf, etc.)
Keep execution time as short as possible
Avoid calling blocking functions or FreeRTOS APIs that are not ISR-safe
Use only stack variables or pre-allocated memory
Consider using xQueueSendFromISR() or similar to defer processing

Parameters

event	Monitor event structure containing threshold event details
user_data	User-provided data pointer

Enumeration Type Documentation

◆ hf_adc_atten_t

enum class hf_adc_atten_t : uint8_t

strong

ADC attenuation levels for ESP32 These control the input voltage range that can be measured Values must match ESP-IDF adc_atten_t enum.

Enumerator
ATTEN_DB_0	No attenuation (0dB) - Input range: 0V to ~0.95V.
ATTEN_DB_2_5	2.5dB attenuation - Input range: 0V to ~1.32V
ATTEN_DB_6	6dB attenuation - Input range: 0V to ~1.98V
ATTEN_DB_12	12dB attenuation - Input range: 0V to ~3.3V

◆ hf_adc_bitwidth_t

enum class hf_adc_bitwidth_t : uint8_t

strong

ADC resolution/bit width settings for ESP32 Values must match ESP-IDF adc_bitwidth_t enum.

Enumerator
WIDTH_9BIT	9-bit resolution (0-511)
WIDTH_10BIT	10-bit resolution (0-1023)
WIDTH_11BIT	11-bit resolution (0-2047)
WIDTH_12BIT	12-bit resolution (0-4095) - Default for ESP32
WIDTH_13BIT	13-bit resolution (0-8191)
WIDTH_DEFAULT	Default width (12-bit for ESP32)

◆ hf_adc_filter_coeff_t

enum class hf_adc_filter_coeff_t : uint8_t

strong

ADC filter coefficient enumeration.

Enumerator
COEFF_2	Coefficient 2.
COEFF_4	Coefficient 4.
COEFF_8	Coefficient 8.
COEFF_16	Coefficient 16.
COEFF_64	Coefficient 64.

◆ hf_adc_mode_t

enum class hf_adc_mode_t : uint8_t

strong

ADC operating modes supported by ESP32.

Enumerator
ONESHOT	One-shot mode for single conversions.
CONTINUOUS	Continuous mode with DMA for high-speed sampling.

◆ hf_adc_monitor_event_type_t

enum class hf_adc_monitor_event_type_t : uint8_t

strong

ADC monitor event type enumeration.

Enumerator
HIGH_THRESH	High threshold exceeded.
LOW_THRESH	Below low threshold.

Function Documentation

◆ AdcChannelToGpio()

constexpr hf_pin_num_t AdcChannelToGpio ( hf_channel_id_t channel_id )

inlineconstexprnoexcept

Convert ADC channel to GPIO pin for ESP32.

Note: This is a simplified mapping function. For accurate conversions, use the ESP-IDF adc_continuous_channel_to_io() function at runtime.

Parameters

channel_id ADC channel ID

Returns: GPIO pin number or HF_INVALID_PIN if invalid

◆ CalcBufferPoolSize()

constexpr uint32_t CalcBufferPoolSize	(	uint32_t	samples_per_frame,
		uint32_t	enabled_channels,
		uint32_t	max_store_frames )

inlineconstexprnoexcept

Calculate total buffer pool size based on frames and enabled channels.

Parameters

samples_per_frame	Number of samples per frame per enabled channel
enabled_channels	Number of enabled channels
max_store_frames	Maximum frames to store

Returns: Buffer pool size in bytes

◆ CalcFrameSize()

constexpr uint32_t CalcFrameSize	(	uint32_t	samples_per_frame,
		uint32_t	enabled_channels )

inlineconstexprnoexcept

Calculate frame size in bytes based on samples per frame and enabled channels.

Parameters

samples_per_frame	Number of samples per frame per enabled channel
enabled_channels	Number of enabled channels

Returns: Frame size in bytes

◆ GetFrameResultCount()

constexpr uint32_t GetFrameResultCount ( uint32_t frame_size )

inlineconstexprnoexcept

Calculate number of conversion results that fit in a frame.

Parameters

frame_size Frame size in bytes

Returns: Number of conversion results

◆ GetMaxInputVoltage()

constexpr uint32_t GetMaxInputVoltage ( hf_adc_atten_t atten )

inlineconstexprnoexcept

Get maximum input voltage for given attenuation.

Parameters

atten Attenuation level

Returns: Maximum input voltage in millivolts

◆ GetMaxRawValue()

constexpr uint32_t GetMaxRawValue ( hf_adc_bitwidth_t bitwidth )

inlineconstexprnoexcept

Get maximum raw value for given bit width.

Parameters

bitwidth ADC bit width

Returns: Maximum raw value

◆ GpioToAdcChannel()

constexpr hf_channel_id_t GpioToAdcChannel ( hf_pin_num_t gpio_pin )

inlineconstexprnoexcept

Convert GPIO pin to ADC channel for ESP32.

Note: This is a simplified mapping function. For accurate conversions, use the ESP-IDF adc_continuous_io_to_channel() function at runtime.

Parameters

gpio_pin GPIO pin number

Returns: ADC channel ID or HF_INVALID_CHANNEL if invalid

◆ IsValidContinuousConfig()

constexpr bool IsValidContinuousConfig	(	uint32_t	samples_per_frame,
		uint32_t	enabled_channels,
		uint32_t	max_store_frames )

inlineconstexprnoexcept

Validate continuous mode configuration parameters.

Parameters

samples_per_frame	Number of samples per frame per enabled channel
enabled_channels	Number of enabled channels
max_store_frames	Maximum frames to store

Returns: true if valid, false otherwise

◆ IsValidFrameSize()

constexpr bool IsValidFrameSize ( uint32_t frame_size )

inlineconstexprnoexcept

Validate that frame size is properly aligned.

Parameters

frame_size Frame size in bytes

Returns: true if valid, false otherwise

Variable Documentation

◆ HF_ESP32_ADC_DATA_BYTES_PER_CONV

constexpr uint32_t HF_ESP32_ADC_DATA_BYTES_PER_CONV

constexpr

Initial value:

=

SOC_ADC_DIGI_DATA_BYTES_PER_CONV

Example of ISR-safe ADC callback implementation.

// Queue handle (global or class member)
static QueueHandle_t adc_data_queue;
 
// ISR-safe callback function
bool adc_continuous_callback(const hf_adc_continuous_data_t* data, void* user_data) {
    // Create a lightweight message for the queue
    AdcDataMessage msg;
    msg.timestamp = data->timestamp_us;
    msg.conversion_count = data->conversion_count;
    msg.size = data->size;
 
    // Try to send to queue (non-blocking)
    BaseType_t higher_priority_task_woken = pdFALSE;
    if (xQueueSendFromISR(adc_data_queue, &msg, &higher_priority_task_woken) == pdTRUE) {
        return higher_priority_task_woken == pdTRUE;
    }
 
    return false; // Continue receiving callbacks
}

ESP32 ADC continuous mode constants Bytes per conversion result from ESP-IDF

◆ HF_ESP32_ADC_DEFAULT_FRAME_SIZE

constexpr uint32_t HF_ESP32_ADC_DEFAULT_FRAME_SIZE = 256

constexpr

Default frame size.

◆ HF_ESP32_ADC_MAX_FRAME_SIZE

constexpr uint32_t HF_ESP32_ADC_MAX_FRAME_SIZE = 1024

constexpr

Maximum frame size.

◆ HF_ESP32_ADC_MIN_FRAME_SIZE

constexpr uint32_t HF_ESP32_ADC_MIN_FRAME_SIZE = 64

constexpr

Minimum frame size.

Classes

Typedefs

Enumerations

Functions

Variables

Detailed Description

Typedef Documentation

◆ hf_adc_continuous_callback_t

◆ hf_adc_monitor_callback_t

Enumeration Type Documentation

◆ hf_adc_atten_t

◆ hf_adc_bitwidth_t

◆ hf_adc_filter_coeff_t

◆ hf_adc_mode_t

◆ hf_adc_monitor_event_type_t

Function Documentation

◆ AdcChannelToGpio()

◆ CalcBufferPoolSize()

◆ CalcFrameSize()

◆ GetFrameResultCount()

◆ GetMaxInputVoltage()

◆ GetMaxRawValue()

◆ GpioToAdcChannel()

◆ IsValidContinuousConfig()

◆ IsValidFrameSize()

Variable Documentation

◆ HF_ESP32_ADC_DATA_BYTES_PER_CONV

◆ HF_ESP32_ADC_DEFAULT_FRAME_SIZE

◆ HF_ESP32_ADC_MAX_FRAME_SIZE

◆ HF_ESP32_ADC_MIN_FRAME_SIZE