kopia lustrzana https://github.com/espressif/esp-idf
177 wiersze
7.1 KiB
C
177 wiersze
7.1 KiB
C
/*
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* SPDX-FileCopyrightText: 2019-2021 Espressif Systems (Shanghai) CO LTD
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <stdint.h>
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#include <stdbool.h>
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#include <string.h>
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#include "esp_types.h"
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#include "esp_err.h"
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#include "esp_log.h"
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#include "esp_check.h"
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#include "esp_efuse_rtc_calib.h"
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#include "hal/adc_ll.h"
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#include "hal/adc_types.h"
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#include "driver/adc_types_legacy.h"
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#include "esp_adc_cal_types_legacy.h"
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#include "../esp_adc_cal_internal_legacy.h"
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const static char LOG_TAG[] = "ADC_CALI";
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/* ------------------------ Characterization Constants ---------------------- */
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// coeff_a is actually a float number
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// it is scaled to put them into uint32_t so that the headers do not have to be changed
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static const int coeff_a_scaling = 65536;
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/**
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* @note Error Calculation
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* Coefficients for calculating the reading voltage error.
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* Four sets of coefficients for atten0 ~ atten3 respectively.
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*
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* For each item, first element is the Coefficient, second element is the Multiple. (Coefficient / Multiple) is the real coefficient.
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*
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* @note {0,0} stands for unused item
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* @note In case of the overflow, these coeffcients are recorded as Absolute Value
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* @note For atten0 ~ 2, error = (K0 * X^0) + (K1 * X^1) + (K2 * X^2); For atten3, error = (K0 * X^0) + (K1 * X^1) + (K2 * X^2) + (K3 * X^3) + (K4 * X^4);
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* @note Above formula is rewritten from the original documentation, please note that the coefficients are re-ordered.
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* @note ADC1 and ADC2 use same coeffients
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*/
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const static uint64_t adc_error_coef_atten[4][5][2] = {
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{{225966470500043, 1e15}, {7265418501948, 1e16}, {109410402681, 1e16}, {0, 0}, {0, 0}}, //atten0
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{{4229623392600516, 1e16}, {731527490903, 1e16}, {88166562521, 1e16}, {0, 0}, {0, 0}}, //atten1
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{{1017859239236435, 1e15}, {97159265299153, 1e16}, {149794028038, 1e16}, {0, 0}, {0, 0}}, //atten2
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{{14912262772850453, 1e16}, {228549975564099, 1e16}, {356391935717, 1e16}, {179964582, 1e16}, {42046, 1e16}} //atten3
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};
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/**
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* Term sign
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* @note ADC1 and ADC2 use same coeffients
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*/
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const static int32_t adc_error_sign[4][5] = {
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{-1, -1, 1, 0, 0}, //atten0
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{ 1, -1, 1, 0, 0}, //atten1
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{-1, -1, 1, 0, 0}, //atten2
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{-1, -1, 1, -1, 1} //atten3
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};
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/* -------------------- Characterization Helper Data Types ------------------ */
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typedef struct {
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uint32_t voltage;
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uint32_t digi;
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} adc_calib_data_ver1;
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typedef struct {
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char version_num;
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adc_unit_t adc_num;
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adc_atten_t atten_level;
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union {
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adc_calib_data_ver1 ver1;
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} efuse_data;
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} adc_calib_parsed_info_t;
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static esp_err_t prepare_calib_data_for(int version_num, adc_unit_t adc_num, adc_atten_t atten, adc_calib_parsed_info_t *parsed_data_storage)
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{
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assert(version_num == 1);
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esp_err_t ret;
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parsed_data_storage->version_num = version_num;
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parsed_data_storage->adc_num = adc_num;
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parsed_data_storage->atten_level = atten;
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uint32_t voltage, digi;
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/**
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* V1 we don't have calibration data for ADC2, using the efuse data of ADC1.
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* Here passing the `adc_num` is just for compatibility
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*/
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ret = esp_efuse_rtc_calib_get_cal_voltage(version_num, adc_num, atten, &digi, &voltage);
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if (ret != ESP_OK) {
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return ret;
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}
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parsed_data_storage->efuse_data.ver1.voltage = voltage;
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parsed_data_storage->efuse_data.ver1.digi = digi;
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return ret;
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}
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/* ----------------------- Characterization Functions ----------------------- */
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/*
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* Estimate the (assumed) linear relationship btwn the measured raw value and the voltage
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* with the previously done measurement when the chip was manufactured.
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*/
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static void calculate_characterization_coefficients(const adc_calib_parsed_info_t *parsed_data, esp_adc_cal_characteristics_t *chars)
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{
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ESP_LOGD(LOG_TAG, "Calib V1, Cal Voltage = %"PRId32", Digi out = %"PRId32, parsed_data->efuse_data.ver1.voltage, parsed_data->efuse_data.ver1.digi);
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chars->coeff_a = coeff_a_scaling * parsed_data->efuse_data.ver1.voltage / parsed_data->efuse_data.ver1.digi;
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chars->coeff_b = 0;
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}
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/* ------------------------- Public API ------------------------------------- */
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esp_err_t esp_adc_cal_check_efuse(esp_adc_cal_value_t source)
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{
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if (source != ESP_ADC_CAL_VAL_EFUSE_TP) {
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return ESP_ERR_NOT_SUPPORTED;
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}
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uint8_t adc_encoding_version = esp_efuse_rtc_calib_get_ver();
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if (adc_encoding_version != 1) {
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// current version only accepts encoding ver 1.
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return ESP_ERR_INVALID_VERSION;
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}
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return ESP_OK;
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}
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esp_adc_cal_value_t esp_adc_cal_characterize(adc_unit_t adc_num,
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adc_atten_t atten,
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adc_bits_width_t bit_width,
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uint32_t default_vref,
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esp_adc_cal_characteristics_t *chars)
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{
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esp_err_t ret;
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adc_calib_parsed_info_t efuse_parsed_data = {0};
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// Check parameters
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ESP_RETURN_ON_FALSE(adc_num == ADC_UNIT_1 || adc_num == ADC_UNIT_2, ESP_ADC_CAL_VAL_NOT_SUPPORTED, LOG_TAG, "Invalid unit num");
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ESP_RETURN_ON_FALSE(chars != NULL, ESP_ADC_CAL_VAL_NOT_SUPPORTED, LOG_TAG, "Ivalid characteristic");
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ESP_RETURN_ON_FALSE(bit_width == ADC_WIDTH_BIT_12, ESP_ADC_CAL_VAL_NOT_SUPPORTED, LOG_TAG, "Invalid bit_width");
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ESP_RETURN_ON_FALSE(atten < SOC_ADC_ATTEN_NUM, ESP_ADC_CAL_VAL_NOT_SUPPORTED, LOG_TAG, "Invalid attenuation");
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int version_num = esp_efuse_rtc_calib_get_ver();
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ESP_RETURN_ON_FALSE(version_num == 1, ESP_ADC_CAL_VAL_NOT_SUPPORTED, LOG_TAG, "No calibration efuse burnt");
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memset(chars, 0, sizeof(esp_adc_cal_characteristics_t));
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// make sure adc is calibrated.
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ret = prepare_calib_data_for(version_num, adc_num, atten, &efuse_parsed_data);
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if (ret != ESP_OK) {
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abort();
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}
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calculate_characterization_coefficients(&efuse_parsed_data, chars);
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ESP_LOGD(LOG_TAG, "adc%d (atten leven %d) calibration done: A:%"PRId32" B:%"PRId32, adc_num, atten, chars->coeff_a, chars->coeff_b);
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// Initialize remaining fields
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chars->adc_num = adc_num;
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chars->atten = atten;
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chars->bit_width = bit_width;
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// in esp32c3 we only use the two point method to calibrate the adc.
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return ESP_ADC_CAL_VAL_EFUSE_TP;
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}
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uint32_t esp_adc_cal_raw_to_voltage(uint32_t adc_reading, const esp_adc_cal_characteristics_t *chars)
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{
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assert(chars != NULL);
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int32_t error = 0;
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uint64_t v_cali_1 = adc_reading * chars->coeff_a / coeff_a_scaling;
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esp_adc_error_calc_param_t param = {
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.v_cali_input = v_cali_1,
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.term_num = (chars->atten == 3) ? 5 : 3,
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.coeff = &adc_error_coef_atten,
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.sign = &adc_error_sign,
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};
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error = esp_adc_cal_get_reading_error(¶m, chars->atten);
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return (int32_t)v_cali_1 - error;
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}
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