reflow-oven-control-sw/stm-firmware/safety/safety-adc.c

/* 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
 * @{
 */

#include <reflow-controller/safety/safety-adc.h>
#include <reflow-controller/periph-config/safety-adc-hwcfg.h>
#include <helper-macros/helper-macros.h>
#include <stm-periph/clock-enable-manager.h>

void safety_adc_init()
{
	rcc_manager_enable_clock(&RCC->APB2ENR, BITMASK_TO_BITNO(SAFETY_ADC_ADC_RCC_MASK));

	/* Enable temperature and VREFINT measurement */
	ADC->CCR |= ADC_CCR_TSVREFE;

	/* Set sample time for channels 16 and 17 */
	SAFETY_ADC_ADC_PERIPHERAL->SMPR1 |= ADC_SMPR1_SMP17 | ADC_SMPR1_SMP16;

	/* Standard sequence. One measurement */
	SAFETY_ADC_ADC_PERIPHERAL->SQR1 = 0UL;
}


void safety_adc_deinit()
{
	SAFETY_ADC_ADC_PERIPHERAL->CR1 = 0UL;
	SAFETY_ADC_ADC_PERIPHERAL->CR2 = 0UL;
	SAFETY_ADC_ADC_PERIPHERAL->SMPR1  = 0UL;
	rcc_manager_enable_clock(&RCC->APB1ENR, BITMASK_TO_BITNO(RCC_APB2ENR_ADC2EN));
}

float safety_adc_convert_channel(enum safety_adc_meas_channel channel, uint16_t analog_value)
{
	float converted_val;

	switch (channel) {
	case SAFETY_ADC_MEAS_TEMP:
		converted_val = (((float)analog_value / 4095.0f * 2500.0f - SAFETY_ADC_TEMP_NOM_MV) /
				 SAFETY_ADC_TEMP_MV_SLOPE) + SAFETY_ADC_TEMP_NOM;
		break;
	case SAFETY_ADC_MEAS_VREF:
		converted_val = (SAFETY_ADC_INT_REF_MV * 4095.0f) / (float)analog_value;
		break;
	default:
		/* Generate NaN value as default return */
		converted_val = 0.0f / 0.0f;
		break;
	}

	return converted_val;
}

int safety_adc_poll_result(uint16_t *adc_result)
{
	int ret = 0;

	if (!adc_result)
		return -1000;

	if (!(SAFETY_ADC_ADC_PERIPHERAL->CR2 & ADC_CR2_ADON)) {
		return -1;
	}

	if (SAFETY_ADC_ADC_PERIPHERAL->SR & ADC_SR_EOC) {
		*adc_result = (uint16_t)SAFETY_ADC_ADC_PERIPHERAL->DR;
		SAFETY_ADC_ADC_PERIPHERAL->CR2 &= ~ADC_CR2_ADON;
		ret = 1;
	}

	return ret;
}

void safety_adc_trigger_meas(enum safety_adc_meas_channel measurement)
{
	switch (measurement) {
	case SAFETY_ADC_MEAS_TEMP:
		SAFETY_ADC_ADC_PERIPHERAL->SQR3 = TEMP_CHANNEL_NUM;
		break;
	case SAFETY_ADC_MEAS_VREF:
		SAFETY_ADC_ADC_PERIPHERAL->SQR3 = INT_REF_CHANNEL_NUM;
		break;
	default:
		return;
	}

	SAFETY_ADC_ADC_PERIPHERAL->CR2 |= ADC_CR2_ADON;
	SAFETY_ADC_ADC_PERIPHERAL->CR2 |= ADC_CR2_SWSTART;
}


/** @} */