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LibrePilot/flight/AHRS/ahrs_adc.c
pip c8a1a6771c Added "AHRS_ADC_GetOverSampling" function
git-svn-id: svn://svn.openpilot.org/OpenPilot/trunk@2308 ebee16cc-31ac-478f-84a7-5cbb03baadba
2010-12-29 10:34:48 +00:00

302 lines
9.4 KiB
C

/**
******************************************************************************
* @addtogroup AHRS AHRS
* @brief The AHRS Modules perform
*
* @{
* @addtogroup AHRS_ADC AHRS ADC
* @brief Specialized ADC code for double buffered DMA for AHRS
* @{
*
*
* @file ahrs.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief INSGPS Test Program
* @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
*/
#include "ahrs_adc.h"
// Remap the ADC DMA handler to this one
void DMA1_Channel1_IRQHandler()
__attribute__ ((alias("AHRS_ADC_DMA_Handler")));
//! Where the raw data is stored
volatile int16_t raw_data_buffer[MAX_SAMPLES]; // Double buffer that DMA just used
//! Various configuration settings
struct {
volatile int16_t *valid_data_buffer;
volatile uint8_t adc_oversample;
int16_t fir_coeffs[MAX_OVERSAMPLING];
} adc_config;
//! Filter coefficients used in decimation. Limited order so filter can't run between samples
float downsampled_buffer[PIOS_ADC_NUM_PINS];
static ADCCallback callback_function = (ADCCallback) NULL;
/* 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;
/**
* @brief Initialise the ADC Peripheral
* @param[in] adc_oversample
* @return
* @arg 1 for success
* @arg 0 for failure
* Currently ignores rates and uses hardcoded values. Need a little logic to
* map from sampling rates and such to ADC constants.
*/
uint8_t AHRS_ADC_Config(int32_t adc_oversample)
{
int32_t i;
adc_config.adc_oversample = adc_oversample;
ADC_DeInit(ADC1);
ADC_DeInit(ADC2);
/* 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
// TODO: update ADC to continuous sampling, configure the sampling rate
/* 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 = ENABLE;
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);
RCC_PCLK2Config(RCC_HCLK_Div16);
/* 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) & raw_data_buffer[0];
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
/* We are double buffering half words from the ADC. Make buffer appropriately sized */
DMA_InitStructure.DMA_BufferSize =
(PIOS_ADC_NUM_CHANNELS * adc_oversample * 2) >> 1;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
/* Note: We read ADC1 and ADC2 in parallel making a word read, also hence the half buffer size */
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 for half conversions too to indicate double buffer */
DMA_ITConfig(DMA1_Channel1, DMA_IT_TC, ENABLE);
DMA_ITConfig(DMA1_Channel1, DMA_IT_HT, 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);
/* Use simple averaging filter for now */
for (int i = 0; i < adc_oversample; i++)
adc_config.fir_coeffs[i] = 1;
adc_config.fir_coeffs[adc_oversample] = adc_oversample;
return 1;
}
/**
* @brief Set a callback function that is executed whenever
* the ADC double buffer swaps
*/
void AHRS_ADC_SetCallback(ADCCallback new_function)
{
callback_function = new_function;
}
/**
* @brief Return the address of the downsampled data buffer
*/
float * AHRS_ADC_GetBuffer(void)
{
return downsampled_buffer;
}
/**
* @brief Return the address of the raw data data buffer
*/
int16_t * AHRS_ADC_GetRawBuffer(void)
{
return (int16_t *) adc_config.valid_data_buffer;
}
/**
* @brief Return the amount of over sampling
*/
uint8_t AHRS_ADC_GetOverSampling(void)
{
return adc_config.adc_oversample;
}
/**
* @brief Set the fir coefficients. Takes as many samples as the
* current filter order plus one (normalization)
*
* @param new_filter Array of adc_oversampling floats plus one for the
* filter coefficients
*/
void AHRS_ADC_SetFIRCoefficients(float * new_filter)
{
// Less than or equal to get normalization constant
for(int i = 0; i <= adc_config.adc_oversample; i++)
adc_config.fir_coeffs[i] = new_filter[i];
}
/**
* @brief Downsample the data for each of the channels then call
* callback function if installed
*/
void AHRS_ADC_downsample_data()
{
uint16_t chan;
uint16_t sample;
for (chan = 0; chan < PIOS_ADC_NUM_CHANNELS; chan++) {
downsampled_buffer[chan] = 0;
for (sample = 0; sample < adc_config.adc_oversample; sample++) {
downsampled_buffer[chan] += adc_config.valid_data_buffer[chan + sample * PIOS_ADC_NUM_CHANNELS] * adc_config.fir_coeffs[sample];
}
downsampled_buffer[chan] /= (float) adc_config.fir_coeffs[adc_config.adc_oversample];
}
if(callback_function != NULL)
callback_function(downsampled_buffer);
}
/**
* @brief Interrupt for half and full buffer transfer
*
* This interrupt handler swaps between the two halfs of the double buffer to make
* sure the ahrs uses the most recent data. Only swaps data when AHRS is idle, but
* really this is a pretense of a sanity check since the DMA engine is consantly
* running in the background. Keep an eye on the ekf_too_slow variable to make sure
* it's keeping up.
*/
void AHRS_ADC_DMA_Handler(void)
{
if (DMA_GetFlagStatus(DMA1_IT_TC1)) { // whole double buffer filled
adc_config.valid_data_buffer =
&raw_data_buffer[1 * PIOS_ADC_NUM_CHANNELS *
adc_config.adc_oversample];
DMA_ClearFlag(DMA1_IT_TC1);
AHRS_ADC_downsample_data();
}
else if (DMA_GetFlagStatus(DMA1_IT_HT1)) {
adc_config.valid_data_buffer =
&raw_data_buffer[0 * PIOS_ADC_NUM_CHANNELS *
adc_config.adc_oversample];
DMA_ClearFlag(DMA1_IT_HT1);
AHRS_ADC_downsample_data();
}
else {
// This should not happen, probably due to transfer errors
DMA_ClearFlag(DMA1_FLAG_GL1);
}
}