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Kevin Thomas 334f511256 Drivers
2026-03-22 20:39:16 -04:00

70 lines
2.6 KiB
C

/**
* @file adc.h
* @brief Header for 12-bit ADC driver (analog pin + internal temperature sensor)
* @author Kevin Thomas
* @date 2025
*
* MIT License
*
* Copyright (c) 2025 Kevin Thomas
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef ADC_H
#define ADC_H
#include <stdint.h>
/**
* @brief Initialize the ADC peripheral and configure an analog GPIO pin
*
* Powers on the ADC block, configures the specified GPIO as an analog input,
* enables the internal temperature sensor on channel 4, and selects the
* given channel as the active input. Must be called once before using any
* other adc_driver_* functions.
*
* @param gpio GPIO pin number for the analog input (26 = ch0, 27 = ch1, 28 = ch2)
* @param channel ADC channel number corresponding to the GPIO (0, 1, or 2)
*/
void adc_driver_init(uint32_t gpio, uint8_t channel);
/**
* @brief Perform a single ADC conversion on the active channel and return millivolts
*
* Reads the 12-bit raw value from the currently selected channel and scales
* it to millivolts using the 3.3 V (3300 mV) full-scale reference.
*
* @return uint32_t Measured voltage in millivolts (0 to 3300)
*/
uint32_t adc_driver_read_mv(void);
/**
* @brief Read the on-chip temperature sensor and return degrees Celsius
*
* Temporarily switches to ADC channel 4 (internal temperature sensor),
* performs a conversion, applies the formula from the RP2350 datasheet,
* then restores the channel that was active before the call.
*
* @return float Die temperature in degrees Celsius
*/
float adc_driver_read_temp_celsius(void);
#endif // ADC_H