Question
no one can help me understand how to use the DMA? please: '(
Posted on October 08, 2012 at 12:47
hi,
I modified an example of the ST microcontroller STM32F4xx need to acquire three channels with a single ADC and using the DMA, but I do not know how to retrieve the data. can you give me a hand? I'll post the code! Thank you and sorry for the English/* Includes ------------------------------------------------------------------*/
#include ''stm32f4xx.h''
#include ''stm324xg_eval.h''
#include ''stm324xg_eval_lcd.h''
#include <
stdio.h
>
/** @addtogroup STM32F4xx_StdPeriph_Examples
* @{
*/
/** @addtogroup ADC_ADC3_DMA
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* used to display the ADC converted value on LCD */
#define PRINT_ON_LCD
#define ADC3_DR_ADDRESS ((uint32_t)0x4001224C)
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
__IO uint16_t ADC3ConvertedValue = 0;
__IO uint16_t ADC3ConvertedValue2 = 0;
__IO uint32_t ADC3ConvertedVoltage = 0;
__IO uint32_t ADC3ConvertedVoltage2 = 0;
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
void ADC3_CH_9_14_15_DMA_Config(void);
#ifdef PRINT_ON_LCD
void Display_Init(void);
void Display(void);
#endif /* PRINT_ON_LCD */
/**
* @brief Main program
* @param None
* @retval None
*/
int main(void)
{
#ifdef PRINT_ON_LCD
/* LCD Display init */
Display_Init();
#endif
/* ADC3 configuration *******************************************************/
/* - Enable peripheral clocks */
/* - DMA2_Stream0 channel2 configuration */
/* - Configure ADC Channe9 14 15 pin as analog input */
/* - Configure ADC3 Channe9 14 15 */
ADC3_CH_9_14_15_DMA_Config();
/* Start ADC3 Software Conversion */
ADC_SoftwareStartConv(ADC3);
while (1)
{
#ifdef PRINT_ON_LCD
/* Display ADC3 converted value on LCD */
Display();
#endif
}
}
/**
* @brief ADC3 channel07 with DMA configuration
* @param None
* @retval None
*/
void ADC3_CH_9_14_15_DMA_Config(void)
{
ADC_InitTypeDef ADC_InitStructure;
ADC_CommonInitTypeDef ADC_CommonInitStructure;
DMA_InitTypeDef DMA_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
/* Enable ADC3, DMA2 and GPIO clocks ****************************************/
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOF, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC3, ENABLE);
/* DMA2 Stream0 channel2 configuration **************************************/
DMA_InitStructure.DMA_Channel = DMA_Channel_2;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC3_DR_ADDRESS;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC3ConvertedValue;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = 3;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(DMA2_Stream0, &DMA_InitStructure);
DMA_Cmd(DMA2_Stream0, ENABLE);
/* Configure ADC3 Channe 9 14 15 pin as analog input ******************************/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
GPIO_Init(GPIOF, &GPIO_InitStructure);
/* ADC Common Init **********************************************************/
ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
ADC_CommonInit(&ADC_CommonInitStructure);
/* ADC3 Init ****************************************************************/
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = DISABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 3; //Perchè effettuo ttue e tre le conversioni dall'ADC3
ADC_Init(ADC3, &ADC_InitStructure);
/* ADC3 regular channel7 configuration *************************************/
/****MODIFICATO*****/
ADC_RegularChannelConfig(ADC3, ADC_Channel_9, 1, ADC_SampleTime_3Cycles); /****MODIFICATO*****/
ADC_RegularChannelConfig(ADC3, ADC_Channel_14, 2, ADC_SampleTime_3Cycles); /****MODIFICATO*****/
ADC_RegularChannelConfig(ADC3, ADC_Channel_15, 3, ADC_SampleTime_3Cycles); /****MODIFICATO*****/
/* Enable DMA request after last transfer (Single-ADC mode) */
ADC_DMARequestAfterLastTransferCmd(ADC3, ENABLE);
/* Enable ADC3 DMA */
ADC_DMACmd(ADC3, ENABLE);
/* Enable ADC3 */
ADC_Cmd(ADC3, ENABLE);
}
#ifdef PRINT_ON_LCD
/**
* @brief Display ADC converted value on LCD
* @param None
* @retval None
*/
void Display(void)
{
uint32_t v=0,mv=0,v2,mv2;
uint8_t text[50];
ADC3ConvertedVoltage = ADC3ConvertedValue *3300/0xFFF;
v=(ADC3ConvertedVoltage)/1000;
mv = (ADC3ConvertedVoltage%1000)/100;
sprintf((char*)text,'' ADC = %d,%d V '',v,mv);
LCD_DisplayStringLine(LINE(6),text);
// I do not know how to take the data from channel 14 or 15 ... Help!//
v2=(ADC3ConvertedVoltage2)/1000;
mv2 = (ADC3ConvertedVoltage2%1000)/100;
sprintf((char*)text,'' ADC = %d,%d V '',v2,mv2);
LCD_DisplayStringLine(LINE(7),text);
}
/**
* @brief Display Init (LCD)
* @param None
* @retval None
*/
void Display_Init(void)
{
/* Initialize the LCD */
STM324xG_LCD_Init();
/* Clear the LCD */
LCD_Clear(White);
/* Set the LCD Text size */
LCD_SetFont(&Font8x12);
/* Set the LCD Back Color and Text Color*/
LCD_SetBackColor(Blue);
LCD_SetTextColor(White);
/* Display */
LCD_DisplayStringLine(LINE(0x13), '' ADC conversion w/ DMA transfer example '');
/* Set the LCD Text size */
LCD_SetFont(&Font16x24);
/* Display */
LCD_DisplayStringLine(LINE(0), ''ADC Ch7 Conv @2.4Msps'');
/* Set the LCD Back Color and Text Color*/
LCD_SetBackColor(White);
LCD_SetTextColor(Blue);
/* Display */
LCD_DisplayStringLine(LINE(2),'' Turn RV1(PF.09) '');
LCD_DisplayStringLine(LINE(4),'' Potentiometer '');
}
#endif /* PRINT_ON_LCD */
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf(''Wrong parameters value: file %s on line %d\r\n'', file, line) */
/* Infinite loop */
while (1)
{
}
}
#endif
/**
* @}
*/
/**
* @}
*/
/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/