73cdfbfe79
This commit updates the esp_adc_cal ocmponent to support new calibration methods which utilize calibratoin values stored in eFuse. This commit includes LUT mode
80 lines
3.4 KiB
C
80 lines
3.4 KiB
C
/* ADC1 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 "driver/gpio.h"
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#include "driver/adc.h"
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#include "esp_adc_cal.h"
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#define PRINT_VAL_SUPPORT(support, type) ({ \
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if(support == ESP_OK){ \
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printf("%s: supported\n", (type)); \
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} else { \
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printf("%s: not supported\n", (type)); \
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} \
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})
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#define PRINT_VAL_TYPE(type, mode) ({ \
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if(type == ESP_ADC_CAL_VAL_EFUSE_TP){ \
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printf("%s mode: Two Point Value\n", (mode)); \
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} else if (type == ESP_ADC_CAL_VAL_EFUSE_VREF){ \
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printf("%s mode: eFuse Vref\n", (mode)); \
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} else { \
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printf("%s mode: Default Vref\n", (mode)); \
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} \
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})
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#define DEFAULT_VREF 1100 //Use adc2_vref_to_gpio() to obtain a better estimate
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#define NO_OF_SAMPLES 64
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static esp_adc_cal_characteristics_t *adc_linear_chars;
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static esp_adc_cal_characteristics_t *adc_lut_chars;
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static adc1_channel_t channel = ADC1_CHANNEL_6;
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void app_main(void)
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{
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//Check if Two Point or Vref are burned into eFuse
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esp_err_t efuse_vref_support = esp_adc_cal_check_efuse(ESP_ADC_CAL_VAL_EFUSE_VREF);
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esp_err_t efuse_tp_support = esp_adc_cal_check_efuse(ESP_ADC_CAL_VAL_EFUSE_TP);
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PRINT_VAL_SUPPORT(efuse_vref_support, "eFuse Vref");
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PRINT_VAL_SUPPORT(efuse_tp_support, "eFuse Two Point");
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//Configure ADC1
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adc1_config_width(ADC_WIDTH_BIT_12);
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adc1_config_channel_atten(channel, ADC_ATTEN_DB_0);
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//Characterize ADC1 in both linear and lut mode
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adc_linear_chars = calloc(1, sizeof(esp_adc_cal_characteristics_t));
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adc_lut_chars = calloc(1, sizeof(esp_adc_cal_characteristics_t));
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esp_adc_cal_value_t lin_val_type = esp_adc_cal_characterize(ADC_UNIT_1, ADC_ATTEN_DB_0, ESP_ADC_CAL_MODE_LIN, DEFAULT_VREF, adc_linear_chars);
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esp_adc_cal_value_t lut_val_type = esp_adc_cal_characterize(ADC_UNIT_1, ADC_ATTEN_DB_0, ESP_ADC_CAL_MODE_LUT, DEFAULT_VREF, adc_lut_chars);
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PRINT_VAL_TYPE(lin_val_type, "Linear");
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PRINT_VAL_TYPE(lut_val_type, "LUT");
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//Continuously sample ADC1
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while(1){
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uint32_t adc1_raw = 0;
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//Multisample
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for(int i = 0; i < NO_OF_SAMPLES; i++){
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adc1_raw += adc1_get_raw(channel);
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}
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adc1_raw /= NO_OF_SAMPLES;
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uint32_t corrected_linear = esp_adc_cal_raw_to_voltage(adc1_raw, ADC_WIDTH_BIT_12, adc_linear_chars);
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uint32_t corrected_lut = esp_adc_cal_raw_to_voltage(adc1_raw, ADC_WIDTH_BIT_12, adc_lut_chars);
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printf("Raw: %d\tLinear: %dmV\tLUT: %dmV\n", adc1_raw, corrected_linear, corrected_lut);
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vTaskDelay(pdMS_TO_TICKS(1000));
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}
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}
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