1 // Copyright 2020 Espressif Systems (Shanghai) PTE LTD 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 // Internal header for calibration, don't use in app 16 17 #include "sdkconfig.h" 18 #include "esp_err.h" 19 #include "hal/adc_hal.h" 20 21 #ifdef __cplusplus 22 extern "C" { 23 #endif 24 25 #if !CONFIG_IDF_TARGET_ESP32 26 27 /** 28 * @brief Calibrate the offset of ADC. (Based on the pre-stored efuse or actual calibration) 29 * 30 * @param adc_n ADC unit to calibrate 31 * @param channel Target channel if really do calibration 32 * @param atten Attenuation to use 33 * @return Always ESP_OK 34 */ 35 extern esp_err_t adc_cal_offset(adc_ll_num_t adc_n, adc_channel_t channel, adc_atten_t atten); 36 37 #endif 38 39 #ifdef __cplusplus 40 } 41 #endif 42