1 /*
2 * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #include <stdio.h>
8 #include <stdint.h>
9 #include "esp_efuse_rtc_calib.h"
10 #include "../curve_fitting_coefficients.h"
11
12 #define COEFF_VERSION_NUM 2 // Currently C6 has two versions of curve calibration schemes
13
14 /**
15 * @note Error Calculation
16 * Coefficients for calculating the reading voltage error.
17 * Four sets of coefficients for atten0 ~ atten3 respectively.
18 *
19 * For each item, first element is the Coefficient, second element is the Multiple. (Coefficient / Multiple) is the real coefficient.
20 *
21 * @note {0,0} stands for unused item
22 * @note In case of the overflow, these coefficients are recorded as Absolute Value
23 * @note For atten0 ~ 3, error = (K0 * X^0) + (K1 * X^1) + (K2 * X^2)
24 * @note Above formula is rewritten from the original documentation, please note that the coefficients are re-ordered.
25 */
26 const static uint64_t adc1_error_coef_atten[COEFF_VERSION_NUM][COEFF_GROUP_NUM][TERM_MAX][2] = {
27 /* Coefficients of calibration version 1 */
28 {
29 {{487166399931449, 1e15}, {6436483033201, 1e16}, {30410131806, 1e16}, {0, 0}, {0, 0}}, //atten0
30 {{8665498165817785, 1e16}, {15239070452946, 1e16}, {13818878844, 1e16}, {0, 0}, {0, 0}}, //atten1
31 {{12277821756674387, 1e16}, {22275554717885, 1e16}, {5924302667, 1e16}, {0, 0}, {0, 0}}, //atten2
32 {{3801417550380255, 1e16}, {6020352420772, 1e16}, {12442478488, 1e16}, {0, 0}, {0, 0}}, //atten3
33 },
34 /* Coefficients of calibration version 2 */
35 {
36 {{0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}}, //atten0
37 {{0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}}, //atten1
38 {{12217864764388775, 1e16}, {1954123107752, 1e16}, {6409679727, 1e16}, {0, 0}, {0, 0}}, //atten2
39 {{3915910437042445 , 1e16}, {31536470857564, 1e16}, {12493873014, 1e16}, {0, 0}, {0, 0}}, //atten3
40 },
41 };
42
43 /**
44 * Term sign
45 */
46 const static int32_t adc1_error_sign[COEFF_VERSION_NUM][COEFF_GROUP_NUM][TERM_MAX] = {
47 /* Coefficient sign of calibration version 1 */
48 {
49 {-1, 1, 1, 0, 0}, //atten0
50 {-1, 1, 1, 0, 0}, //atten1
51 {-1, 1, 1, 0, 0}, //atten2
52 {-1, -1, 1, 0, 0}, //atten3
53 },
54 /* Coefficient sign of calibration version 2 */
55 {
56 { 0, 0, 0, 0, 0}, //atten0
57 { 0, 0, 0, 0, 0}, //atten1
58 {-1, -1, 1, 0, 0}, //atten2
59 {-1, -1, 1, 0, 0}, //atten3
60 },
61 };
62
63
curve_fitting_get_second_step_coeff(const adc_cali_curve_fitting_config_t * config,cali_chars_second_step_t * ctx)64 void curve_fitting_get_second_step_coeff(const adc_cali_curve_fitting_config_t *config, cali_chars_second_step_t *ctx)
65 {
66 uint32_t adc_calib_ver = esp_efuse_rtc_calib_get_ver();
67 assert((adc_calib_ver >= ESP_EFUSE_ADC_CALIB_VER_MIN) &&
68 (adc_calib_ver <= ESP_EFUSE_ADC_CALIB_VER_MAX));
69 ctx->term_num = 3;
70 ctx->coeff = &adc1_error_coef_atten[VER2IDX(adc_calib_ver)];
71 ctx->sign = &adc1_error_sign[VER2IDX(adc_calib_ver)];
72 }
73
