LibrePilot/flight/PiOS/STM32F10x/pios_adc.c

/**
 ******************************************************************************
 * @addtogroup PIOS PIOS Core hardware abstraction layer
 * @{
 * @addtogroup   PIOS_ADC ADC Functions
 * @brief STM32 ADC PIOS interface
 * @{
 *
 * @file       pios_adc.c  
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * 	        Parts by Thorsten Klose (tk@midibox.org) (tk@midibox.org)
 * @brief      Analog to Digital converstion routines
 * @see        The GNU Public License (GPL) Version 3
 *****************************************************************************/
/* 
 * This program is free software; you can redistribute it and/or modify 
 * it under the terms of the GNU General Public License as published by 
 * the Free Software Foundation; either version 3 of the License, or 
 * (at your option) any later version.
 * 
 * This program 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 this program; if not, write to the Free Software Foundation, Inc., 
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/* Project Includes */
#include "pios.h"

#if defined(PIOS_INCLUDE_ADC)

/* Local Variables */
static GPIO_TypeDef *ADC_GPIO_PORT[PIOS_ADC_NUM_PINS] = PIOS_ADC_PORTS;
static const uint32_t ADC_GPIO_PIN[PIOS_ADC_NUM_PINS] = PIOS_ADC_PINS;
static const uint32_t ADC_CHANNEL[PIOS_ADC_NUM_PINS] = PIOS_ADC_CHANNELS;

static ADC_TypeDef *ADC_MAPPING[PIOS_ADC_NUM_PINS] = PIOS_ADC_MAPPING;
static const uint32_t ADC_CHANNEL_MAPPING[PIOS_ADC_NUM_PINS] = PIOS_ADC_CHANNEL_MAPPING;

/* The following two arrays are word aligned, so that DMA can transfer two hwords at once */
static uint16_t adc_conversion_values[PIOS_ADC_NUM_CHANNELS] __attribute__ ((aligned(4)));
//static uint16_t adc_conversion_values_sum[PIOS_ADC_NUM_CHANNELS]; __attribute__((aligned(4)));

static uint16_t adc_pin_values[PIOS_ADC_NUM_CHANNELS];

/**
* Initialise the ADC Peripheral
*/
void PIOS_ADC_Init(void)
{
	int32_t i;

	/* Clear arrays and variables */
	for (i = 0; i < PIOS_ADC_NUM_CHANNELS; ++i) {
		adc_conversion_values[i] = 0;
	}
	for (i = 0; i < PIOS_ADC_NUM_CHANNELS; ++i) {
		adc_pin_values[i] = 0;
	}

	/* Setup analog pins */
	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_StructInit(&GPIO_InitStructure);
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;

	/* Enable each ADC pin in the array */
	for (i = 0; i < PIOS_ADC_NUM_PINS; i++) {
		GPIO_InitStructure.GPIO_Pin = ADC_GPIO_PIN[i];
		GPIO_Init(ADC_GPIO_PORT[i], &GPIO_InitStructure);
	}

	/* Enable ADC clocks */
	PIOS_ADC_CLOCK_FUNCTION;

	/* Map channels to conversion slots depending on the channel selection mask */
	for (i = 0; i < PIOS_ADC_NUM_PINS; i++) {
		ADC_RegularChannelConfig(ADC_MAPPING[i], ADC_CHANNEL[i], ADC_CHANNEL_MAPPING[i], PIOS_ADC_SAMPLE_TIME);
	}

#if (PIOS_ADC_USE_TEMP_SENSOR)
	ADC_TempSensorVrefintCmd(ENABLE);
	ADC_RegularChannelConfig(PIOS_ADC_TEMP_SENSOR_ADC, ADC_Channel_14, PIOS_ADC_TEMP_SENSOR_ADC_CHANNEL, PIOS_ADC_SAMPLE_TIME);
#endif

	/* Configure ADCs */
	ADC_InitTypeDef ADC_InitStructure;
	ADC_StructInit(&ADC_InitStructure);
	ADC_InitStructure.ADC_Mode = ADC_Mode_RegSimult;
	ADC_InitStructure.ADC_ScanConvMode = ENABLE;
	ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
	ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
	ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
	ADC_InitStructure.ADC_NbrOfChannel = ((PIOS_ADC_NUM_CHANNELS + 1) >> 1);
	ADC_Init(ADC1, &ADC_InitStructure);

#if (PIOS_ADC_USE_ADC2)
	ADC_Init(ADC2, &ADC_InitStructure);

	/* Enable ADC2 external trigger conversion (to synch with ADC1) */
	ADC_ExternalTrigConvCmd(ADC2, ENABLE);
#endif

	//RCC_ADCCLKConfig(PIOS_ADC_ADCCLK);

	/* Enable ADC1->DMA request */
	ADC_DMACmd(ADC1, ENABLE);

	/* ADC1 calibration */
	ADC_Cmd(ADC1, ENABLE);
	ADC_ResetCalibration(ADC1);
	while (ADC_GetResetCalibrationStatus(ADC1)) ;
	ADC_StartCalibration(ADC1);
	while (ADC_GetCalibrationStatus(ADC1)) ;

#if (PIOS_ADC_USE_ADC2)
	/* ADC2 calibration */
	ADC_Cmd(ADC2, ENABLE);
	ADC_ResetCalibration(ADC2);
	while (ADC_GetResetCalibrationStatus(ADC2)) ;
	ADC_StartCalibration(ADC2);
	while (ADC_GetCalibrationStatus(ADC2)) ;
#endif

	/* Enable DMA1 clock */
	RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

	/* Configure DMA1 channel 1 to fetch data from ADC result register */
	DMA_InitTypeDef DMA_InitStructure;
	DMA_StructInit(&DMA_InitStructure);
	DMA_DeInit(DMA1_Channel1);
	DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t) & ADC1->DR;
	DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t) & adc_conversion_values;
	DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
	DMA_InitStructure.DMA_BufferSize = ((PIOS_ADC_NUM_CHANNELS + 1) >> 1);	/* Number of conversions depends on number of used channels */
	DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
	DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
	DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
	DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
	DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
	DMA_InitStructure.DMA_Priority = DMA_Priority_High;
	DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
	DMA_Init(DMA1_Channel1, &DMA_InitStructure);
	DMA_Cmd(DMA1_Channel1, ENABLE);

	/* Trigger interrupt when all conversion values have been fetched */
	DMA_ITConfig(DMA1_Channel1, DMA_IT_TC, ENABLE);

	/* Configure and enable DMA interrupt */
	NVIC_InitTypeDef NVIC_InitStructure;
	NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = PIOS_ADC_IRQ_PRIO;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);

	/* Finally start initial conversion */
	ADC_SoftwareStartConvCmd(ADC1, ENABLE);
}

/**
* Returns value of an ADC Pin
* \param[in] pin number
* \return ADC pin value - resolution depends on the selected oversampling rate
* \return -1 if pin doesn't exist
*/
int32_t PIOS_ADC_PinGet(uint32_t pin)
{
	/* Check if pin exists */
	if (pin >= PIOS_ADC_NUM_CHANNELS) {
		return -1;
	}

	/* Return last conversion result */
	return adc_pin_values[pin];
}

/**
* DMA channel interrupt is triggered when all ADC channels have been converted
* \note shouldn't be called directly from application
*/
void DMA1_Channel1_IRQHandler(void)
{
	int32_t i;
	uint16_t *src_ptr;

	/* Clear the pending flag(s) */
	DMA_ClearFlag(DMA1_FLAG_TC1 | DMA1_FLAG_TE1 | DMA1_FLAG_HT1 | DMA1_FLAG_GL1);

	src_ptr = (uint16_t *) adc_conversion_values;

	/* Copy conversion values to adc_pin_values */
	for (i = 0; i < PIOS_ADC_NUM_CHANNELS; ++i) {
		/* Takeover new value */
		adc_pin_values[i] = *src_ptr;
		++src_ptr;
	}

	/* Request next conversion */
	ADC_SoftwareStartConvCmd(ADC1, ENABLE);
}

#endif

/** 
 * @}
 * @}
 */