/*
* SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <string.h>
#include <stdio.h>
#include "sdkconfig.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "esp_adc/adc_continuous.h"
#define EXAMPLE_READ_LEN 256
#define GET_UNIT(x) ((x>>3) & 0x1)
#if CONFIG_IDF_TARGET_ESP32
#define ADC_CONV_MODE ADC_CONV_SINGLE_UNIT_1 //ESP32 only supports ADC1 DMA mode
#define ADC_OUTPUT_TYPE ADC_DIGI_OUTPUT_FORMAT_TYPE1
#elif CONFIG_IDF_TARGET_ESP32S2
#define ADC_CONV_MODE ADC_CONV_BOTH_UNIT
#define ADC_OUTPUT_TYPE ADC_DIGI_OUTPUT_FORMAT_TYPE2
#elif CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32H4 || CONFIG_IDF_TARGET_ESP32C2
#define ADC_CONV_MODE ADC_CONV_ALTER_UNIT //ESP32C3 only supports alter mode
#define ADC_OUTPUT_TYPE ADC_DIGI_OUTPUT_FORMAT_TYPE2
#elif CONFIG_IDF_TARGET_ESP32S3
#define ADC_CONV_MODE ADC_CONV_BOTH_UNIT
#define ADC_OUTPUT_TYPE ADC_DIGI_OUTPUT_FORMAT_TYPE2
#endif
#if CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32S3 || CONFIG_IDF_TARGET_ESP32H4 || CONFIG_IDF_TARGET_ESP32C2
static adc_channel_t channel[3] = {ADC_CHANNEL_2, ADC_CHANNEL_3, (ADC_CHANNEL_0 | 1 << 3)};
#endif
#if CONFIG_IDF_TARGET_ESP32S2
static adc_channel_t channel[3] = {ADC_CHANNEL_2, ADC_CHANNEL_3, (ADC_CHANNEL_0 | 1 << 3)};
#endif
#if CONFIG_IDF_TARGET_ESP32
static adc_channel_t channel[1] = {ADC_CHANNEL_7};
#endif
static TaskHandle_t s_task_handle;
static const char *TAG = "EXAMPLE";
static bool IRAM_ATTR s_conv_done_cb(adc_continuous_handle_t handle, const adc_continuous_evt_data_t *edata, void *user_data)
{
BaseType_t mustYield = pdFALSE;
//Notify that ADC continuous driver has done enough number of conversions
vTaskNotifyGiveFromISR(s_task_handle, &mustYield);
return (mustYield == pdTRUE);
}
static void continuous_adc_init(adc_channel_t *channel, uint8_t channel_num, adc_continuous_handle_t *out_handle)
{
adc_continuous_handle_t handle = NULL;
adc_continuous_handle_cfg_t adc_config = {
.max_store_buf_size = 1024,
.conv_frame_size = EXAMPLE_READ_LEN,
};
ESP_ERROR_CHECK(adc_continuous_new_handle(&adc_config, &handle));
adc_continuous_config_t dig_cfg = {
.sample_freq_hz = 20 * 1000,
.conv_mode = ADC_CONV_MODE,
.format = ADC_OUTPUT_TYPE,
};
adc_digi_pattern_config_t adc_pattern[SOC_ADC_PATT_LEN_MAX] = {0};
dig_cfg.pattern_num = channel_num;
for (int i = 0; i < channel_num; i++) {
uint8_t unit = GET_UNIT(channel[i]);
uint8_t ch = channel[i] & 0x7;
adc_pattern[i].atten = ADC_ATTEN_DB_0;
adc_pattern[i].channel = ch;
adc_pattern[i].unit = unit;
adc_pattern[i].bit_width = SOC_ADC_DIGI_MAX_BITWIDTH;
ESP_LOGI(TAG, "adc_pattern[%d].atten is :%x", i, adc_pattern[i].atten);
ESP_LOGI(TAG, "adc_pattern[%d].channel is :%x", i, adc_pattern[i].channel);
ESP_LOGI(TAG, "adc_pattern[%d].unit is :%x", i, adc_pattern[i].unit);
}
dig_cfg.adc_pattern = adc_pattern;
ESP_ERROR_CHECK(adc_continuous_config(handle, &dig_cfg));
*out_handle = handle;
}
#if !CONFIG_IDF_TARGET_ESP32
static bool check_valid_data(const adc_digi_output_data_t *data)
{
const unsigned int unit = data->type2.unit;
if (unit > 2) return false;
if (data->type2.channel >= SOC_ADC_CHANNEL_NUM(unit)) return false;
return true;
}
#endif
void app_main(void)
{
esp_err_t ret;
uint32_t ret_num = 0;
uint8_t result[EXAMPLE_READ_LEN] = {0};
memset(result, 0xcc, EXAMPLE_READ_LEN);
s_task_handle = xTaskGetCurrentTaskHandle();
adc_continuous_handle_t handle = NULL;
continuous_adc_init(channel, sizeof(channel) / sizeof(adc_channel_t), &handle);
adc_continuous_evt_cbs_t cbs = {
.on_conv_done = s_conv_done_cb,
};
ESP_ERROR_CHECK(adc_continuous_register_event_callbacks(handle, &cbs, NULL));
ESP_ERROR_CHECK(adc_continuous_start(handle));
while(1) {
/**
* This is to show you the way to use the ADC continuous mode driver event callback.
* This `ulTaskNotifyTake` will block when the data processing in the task is fast.
* However in this example, the data processing (print) is slow, so you barely block here.
*
* Without using this event callback (to notify this task), you can still just call
* `adc_continuous_read()` here in a loop, with/without a certain block timeout.
*/
ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
while (1) {
ret = adc_continuous_read(handle, result, EXAMPLE_READ_LEN, &ret_num, 0);
if (ret == ESP_OK) {
ESP_LOGI("TASK", "ret is %x, ret_num is %"PRIu32, ret, ret_num);
for (int i = 0; i < ret_num; i += SOC_ADC_DIGI_RESULT_BYTES) {
adc_digi_output_data_t *p = (void*)&result[i];
#if CONFIG_IDF_TARGET_ESP32
ESP_LOGI(TAG, "Unit: %d, Channel: %d, Value: %x", 1, p->type1.channel, p->type1.data);
#else
if (ADC_CONV_MODE == ADC_CONV_BOTH_UNIT || ADC_CONV_MODE == ADC_CONV_ALTER_UNIT) {
if (check_valid_data(p)) {
ESP_LOGI(TAG, "Unit: %d,_Channel: %d, Value: %x", p->type2.unit+1, p->type2.channel, p->type2.data);
} else {
ESP_LOGI(TAG, "Invalid data [%d_%d_%x]", p->type2.unit+1, p->type2.channel, p->type2.data);
}
}
#if CONFIG_IDF_TARGET_ESP32S2
else if (ADC_CONV_MODE == ADC_CONV_SINGLE_UNIT_2) {
ESP_LOGI(TAG, "Unit: %d, Channel: %d, Value: %x", 2, p->type1.channel, p->type1.data);
} else if (ADC_CONV_MODE == ADC_CONV_SINGLE_UNIT_1) {
ESP_LOGI(TAG, "Unit: %d, Channel: %d, Value: %x", 1, p->type1.channel, p->type1.data);
}
#endif //#if CONFIG_IDF_TARGET_ESP32S2
#endif
}
/**
* Because printing is slow, so every time you call `ulTaskNotifyTake`, it will immediately return.
* To avoid a task watchdog timeout, add a delay here. When you replace the way you process the data,
* usually you don't need this delay (as this task will block for a while).
*/
vTaskDelay(1);
} else if (ret == ESP_ERR_TIMEOUT) {
//We try to read `EXAMPLE_READ_LEN` until API returns timeout, which means there's no available data
break;
}
}
}
ESP_ERROR_CHECK(adc_continuous_stop(handle));
ESP_ERROR_CHECK(adc_continuous_deinit(handle));
}