esp-idf/components/esp_adc/esp32s3/curve_fitting_coefficients.c
laokaiyao edc1abc8ea refactor(adc_calib): Simplify 2nd step coefficient calculation
- remove unnecessary variables and calculations
- improve readability of code
2023-07-06 14:22:03 +08:00

64 lines
3.9 KiB
C

/*
* SPDX-FileCopyrightText: 2019-2023 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <stdint.h>
#include "hal/adc_types.h"
#include "../curve_fitting_coefficients.h"
#define COEFF_GROUP_NUM 4
#define TERM_MAX 5
/**
* @note Error Calculation
* Coefficients for calculating the reading voltage error.
* Four sets of coefficients for atten0 ~ atten3 respectively.
*
* For each item, first element is the Coefficient, second element is the Multiple. (Coefficient / Multiple) is the real coefficient.
*
* @note {0,0} stands for unused item
* @note In case of the overflow, these coefficients are recorded as Absolute Value
* @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);
* @note Above formula is rewritten from the original documentation, please note that the coefficients are re-ordered.
*/
const static uint64_t adc1_error_coef_atten[COEFF_GROUP_NUM][TERM_MAX][2] = {
{{27856531419538344, 1e16}, {50871540569528, 1e16}, {9798249589, 1e15}, {0, 0}, {0, 0}}, //ADC1 atten0
{{29831022915028695, 1e16}, {49393185868806, 1e16}, {101379430548, 1e16}, {0, 0}, {0, 0}}, //ADC1 atten1
{{23285545746296417, 1e16}, {147640181047414, 1e16}, {208385525314, 1e16}, {0, 0}, {0, 0}}, //ADC1 atten2
{{644403418269478, 1e15}, {644334888647536, 1e16}, {1297891447611, 1e16}, {70769718, 1e15}, {13515, 1e15}} //ADC1 atten3
};
const static uint64_t adc2_error_coef_atten[COEFF_GROUP_NUM][TERM_MAX][2] = {
{{25668651654328927, 1e16}, {1353548869615, 1e16}, {36615265189, 1e16}, {0, 0}, {0, 0}}, //ADC2 atten0
{{23690184690298404, 1e16}, {66319894226185, 1e16}, {118964995959, 1e16}, {0, 0}, {0, 0}}, //ADC2 atten1
{{9452499397020617, 1e16}, {200996773954387, 1e16}, {259011467956, 1e16}, {0, 0}, {0, 0}}, //ADC2 atten2
{{12247719764336924,1e16}, {755717904943462, 1e16}, {1478791187119, 1e16}, {79672528, 1e15}, {15038, 1e15}} //ADC2 atten3
};
/**
* Term sign
*/
const static int32_t adc1_error_sign[COEFF_GROUP_NUM][TERM_MAX] = {
{-1, -1, 1, 0, 0}, //ADC1 atten0
{-1, -1, 1, 0, 0}, //ADC1 atten1
{-1, -1, 1, 0, 0}, //ADC1 atten2
{-1, -1, 1, -1, 1} //ADC1 atten3
};
const static int32_t adc2_error_sign[COEFF_GROUP_NUM][TERM_MAX] = {
{-1, 1, 1, 0, 0}, //ADC2 atten0
{-1, -1, 1, 0, 0}, //ADC2 atten1
{-1, -1, 1, 0, 0}, //ADC2 atten2
{ 1, -1, 1, -1, 1} //ADC2 atten3
};
void curve_fitting_get_second_step_coeff(const adc_cali_curve_fitting_config_t *config, cali_chars_second_step_t *ctx)
{
ctx->term_num = (config->atten == 3) ? 5 : 3;
ctx->coeff = config->unit_id == ADC_UNIT_1 ?
adc1_error_coef_atten[config->atten] :
adc2_error_coef_atten[config->atten];
ctx->sign = config->unit_id == ADC_UNIT_1 ?
adc1_error_sign[config->atten] :
adc2_error_sign[config->atten];
}