/* * SPDX-FileCopyrightText: 2019-2021 Espressif Systems (Shanghai) CO LTD * * SPDX-License-Identifier: Apache-2.0 */ #include /** * @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 coeffcients 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. * @note ADC1 and ADC2 use same coeffients */ const uint64_t adc1_error_coef_atten[4][5][2] = { {{225966470500043, 1e15}, {7265418501948, 1e16}, {109410402681, 1e16}, {0, 0}, {0, 0}}, //atten0 {{4229623392600516, 1e16}, {731527490903, 1e16}, {88166562521, 1e16}, {0, 0}, {0, 0}}, //atten1 {{1017859239236435, 1e15}, {97159265299153, 1e16}, {149794028038, 1e16}, {0, 0}, {0, 0}}, //atten2 {{14912262772850453, 1e16}, {228549975564099, 1e16}, {356391935717, 1e16}, {179964582, 1e16}, {42046, 1e16}} //atten3 }; /** * Term sign */ const int32_t adc1_error_sign[4][5] = { {-1, -1, 1, 0, 0}, //atten0 { 1, -1, 1, 0, 0}, //atten1 {-1, -1, 1, 0, 0}, //atten2 {-1, -1, 1, -1, 1} //atten3 };