88b05f9391
Added component containg API that is able to correct raw ADC readings into a voltage in mV. Also provided a helper function that combines the process of getting the raw ADC1 reading then converting it to a voltage in mV. In doing so, the adc1_get_voltage() function of the ADC driver has been deprecated. Instead there is now adc1_get_raw to obtain the raw ADC1 reading, and adc1_to_voltage() that gets the raw reading and converts all in one function. Functions using the deprecated adc1_get_voltage() have also been updated to use adc1_get_raw(). Conversion is based on ADC characteristics. The characteristics are based on the ADC's v_ref, herefore the appropriate structure and functions have been provided to obtain the ADC characteristics. The existing ADC driver has also been modified by adding a function to route the internal ADC reference voltage to a GPIO allowing users to measure it manually. Relevant documentation has also been updated
97 lines
2.6 KiB
C
97 lines
2.6 KiB
C
// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "esp_adc_cal.h"
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/**
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* Mean error of 219 modules: 3.756418mV
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* Max error of 219 modules: 26.314087mV
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* Mean of max errors of 219 modules: 7.387282mV
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*/
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const esp_adc_cal_lookup_table_t esp_adc_cal_table_atten_0 = {
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.gain_m = 56,
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.gain_c = 59928,
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.offset_m = 91,
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.offset_c = 52798,
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.bit_shift = 7,
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.voltage = {
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54, 90, 120, 150, 180, 209, 241, 271,
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301, 330, 360, 391, 421, 450, 480, 511,
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541, 571, 601, 630, 660, 690, 720, 750,
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780, 809, 839, 870, 900, 929, 959, 988,
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1018
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}
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};
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/**
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* Mean error of 219 modules: 4.952441mV
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* Max error of 219 modules: 38.235321mV
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* Mean of max errors of 219 modules: 9.718749mV
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*/
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const esp_adc_cal_lookup_table_t esp_adc_cal_table_atten_1 = {
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.gain_m = 57,
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.gain_c = 59834,
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.offset_m = 108,
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.offset_c = 54733,
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.bit_shift = 7,
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.voltage = {
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60, 102, 143, 184, 223, 262, 303, 343,
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383, 423, 463, 503, 543, 583, 623, 663,
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703, 742, 782, 823, 862, 901, 942, 981,
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1022, 1060, 1101, 1141, 1180, 1219, 1259, 1298,
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1338
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}
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};
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/**
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* Mean error of 219 modules: 6.793558mV
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* Max error of 219 modules: 51.435440mV
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* Mean of max errors of 219 modules: 13.083121mV
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*/
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const esp_adc_cal_lookup_table_t esp_adc_cal_table_atten_2 = {
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.gain_m = 56,
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.gain_c = 59927,
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.offset_m = 154,
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.offset_c = 71995,
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.bit_shift = 7,
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.voltage = {
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82, 138, 194, 250, 305, 360, 417, 473,
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529, 584, 639, 696, 751, 806, 861, 917,
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971, 1026, 1081, 1136, 1192, 1246, 1301, 1356,
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1411, 1466, 1522, 1577, 1632, 1687, 1743, 1799,
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1855
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}
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};
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/**
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* Mean error of 219 modules: 13.149460mV
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* Max error of 219 modules: 97.102951mV
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* Mean of max errors of 219 modules: 35.538924mV
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*/
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const esp_adc_cal_lookup_table_t esp_adc_cal_table_atten_3 = {
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.gain_m = 33,
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.gain_c = 62214,
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.offset_m = 610,
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.offset_c = 108422,
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.bit_shift = 7,
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.voltage = {
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110, 221, 325, 430, 534, 637, 741, 845,
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947, 1049, 1153, 1256, 1358, 1461, 1565, 1670,
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1774, 1878, 1983, 2088, 2192, 2293, 2393, 2490,
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2580, 2665, 2746, 2820, 2885, 2947, 3007, 3060,
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3107
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}
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};
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