60 lines
2 KiB
C
60 lines
2 KiB
C
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/* ADC2 Example
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This example code is in the Public Domain (or CC0 licensed, at your option.)
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Unless required by applicable law or agreed to in writing, this
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software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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CONDITIONS OF ANY KIND, either express or implied.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include "freertos/FreeRTOS.h"
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#include "freertos/task.h"
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#include "freertos/queue.h"
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#include "driver/gpio.h"
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#include "driver/adc.h"
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#include "driver/dac.h"
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#include "esp_system.h"
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#include "esp_adc_cal.h"
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#define DAC_EXAMPLE_CHANNEL CONFIG_DAC_EXAMPLE_CHANNEL
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#define ADC2_EXAMPLE_CHANNEL CONFIG_ADC2_EXAMPLE_CHANNEL
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void app_main(void)
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{
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uint8_t output_data=0;
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int read_raw;
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esp_err_t r;
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gpio_num_t adc_gpio_num, dac_gpio_num;
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assert( adc2_pad_get_io_num( ADC2_EXAMPLE_CHANNEL, &adc_gpio_num ) == ESP_OK );
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assert( dac_pad_get_io_num( DAC_EXAMPLE_CHANNEL, &dac_gpio_num ) == ESP_OK );
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printf("ADC channel %d @ GPIO %d, DAC channel %d @ GPIO %d.\n", ADC2_EXAMPLE_CHANNEL, adc_gpio_num,
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DAC_EXAMPLE_CHANNEL, dac_gpio_num );
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dac_output_enable( DAC_EXAMPLE_CHANNEL );
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//be sure to do the init before using adc2.
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printf("adc2_init...\n");
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adc2_config_channel_atten( ADC2_EXAMPLE_CHANNEL, ADC_ATTEN_0db );
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vTaskDelay(2 * portTICK_PERIOD_MS);
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printf("start conversion.\n");
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while(1) {
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dac_output_voltage( DAC_EXAMPLE_CHANNEL, output_data++ );
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r = adc2_get_raw( ADC2_EXAMPLE_CHANNEL, ADC_WIDTH_12Bit, &read_raw);
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if ( r == ESP_OK ) {
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printf("%d: %d\n", output_data, read_raw );
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} else if ( r == ESP_ERR_INVALID_STATE ) {
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printf("ADC2 not initialized yet.\n");
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} else if ( r == ESP_ERR_TIMEOUT ) {
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//This can not happen in this example. But if WiFi is in use, such error code could be returned.
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printf("ADC2 is in use by Wi-Fi.\n");
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}
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vTaskDelay( 2 * portTICK_PERIOD_MS );
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}
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}
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