reflow-oven-control-sw/stm-firmware/include/reflow-controller/safety/safety-adc.h

/* Reflow Oven Controller
*
* Copyright (C) 2020  Mario Hüttel <mario.huettel@gmx.net>
*
* This file is part of the Reflow Oven Controller Project.
*
* The reflow oven controller is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* The Reflow Oven Control Firmware is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with the reflow oven controller project.
* If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @addtogroup safety-adc
 * @{
 */

#ifndef __SAFETY_ADC_H__
#define __SAFETY_ADC_H__

#include <stdint.h>
#include <stdbool.h>

/**
 * @brief The safety ADC's measure channel
 */
enum safety_adc_meas_channel {
	SAFETY_ADC_MEAS_VREF, /**< @brief Internal reference voltage @note This will not output the internal reference voltage but the recalculated external voltage! */
	SAFETY_ADC_MEAS_TEMP, /**< @brief Internal temperature sensor */
	SAFETY_ADC_MEAS_SUPPLY, /**< @brief Supply voltage */
};

/**
 * @brief Initialize safety ADC. Only call this function once!
 */
void safety_adc_init(void);

/**
 * @brief safety_adc_deinit Deactivate safety ADC
 * @warning For completeness. Do not call! the safety ADC is a vital component. It's malfunction will trigger a critical safety flag.
 */
void safety_adc_deinit(void);

/**
 * @brief safety_adc_trigger_meas
 */
void safety_adc_trigger_meas(void);

/**
 * @brief Poll ADC result.
 * @return 1 if measurement successful, 0 if not ready, -1 if ADC aborted or not started
 */
int safety_adc_poll_result(void);

/**
 * @brief Get the sampled signal values of the safety ADC.
 *
 * Use #safety_adc_poll_result to poll for a finished conversion of the safety ADC.
 * After that, it is safe to use the output values until a new conversion is triggered using #safety_adc_trigger_meas
 *
 * @warning This function return a constant buffer, that is directly written on by the DMA! Check #safety_adc_poll_result to prevent race conditions.
 * @return Array of raw ADC readings with lenght of #SAFETY_ADC_NUM_OF_CHANNELS
 */
const uint16_t *safety_adc_get_values(void);

/**
 * @brief Convert a safety ADC raw value to an actual signal value
 * @param channel Measurment channel to convert voltage for
 * @param analog_value Raw value of the ADC to convert
 * @warning Double check @ref safety_adc_meas_channel to make sure you understand the output of this function correctly.
 * @return
 */
float safety_adc_convert_channel(enum safety_adc_meas_channel channel, uint16_t analog_value);

#endif /* __SAFETY_ADC_H__ */

/** @} */