ADC Triple Mode with DMA - Blank for ADC1 Only

[lux]

Posted on October 09, 2014 at 19:27

For Adc1 I am still reading 0.0, but Adc2 and Adc3 are fine. Any ideas?

Where do you go to check theCDR_ADDRESS for ADC1, ADC2, and ADC3? The data sheet of my STM32F207-SK board is located

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00237pdf

. Your kindness and guidance is greatly appreciated. Hopefully, I will gain enough knowledge about this micro so that I can pass it on to other people.

Below is my Code:

static volatile Int32U TimingDelay;

int i;

__IO Int16U Adcdata[3];

__IO float Adc1=0;
float Adc1_avg=0;

__IO float Adc2=0;
float Adc2_avg=0;

__IO float Adc3=0;
float Adc3_avg=0;
/**************************************************************************************/
void
RCC_Configuration(
void
)
{
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOC | RCC_AHB1Periph_GPIOB | RCC_AHB1Periph_GPIOA | RCC_AHB1Periph_GPIOE, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_ADC2 | RCC_APB2Periph_ADC3, ENABLE);
}
/**************************************************************************************/
void
DelayResolution100us(Int32U Dly)
{ 
TimingDelay = Dly;
while
(TimingDelay != 0);
}
/**
* @brief Decrements the TimingDelay variable.
* @param None
* @retval None
*/
void
TimingDelay_Decrement(
void
)
{
if
(TimingDelay != 0x00)
{ 
TimingDelay--;
}
}
void
GPIO_Configuration(
void
)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* ADC Channel 8 -> PB0 ADC12_IN8
ADC Channel 15 -> PC5 ADC12_IN15
ADC Channel 0 -> PA0 ADC123_IN0
*/
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_Init(GPIOC, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_Init(GPIOA, &GPIO_InitStructure);
}
/**************************************************************************************/
void
ADC_Configuration(
void
)
{
ADC_DeInit();
ADC_CommonInitTypeDef ADC_CommonInitStructure;
ADC_InitTypeDef ADC_InitStructure;
/* ADC Common Init - COMMON - Do it once, do it first */
ADC_CommonInitStructure.ADC_Mode = ADC_TripleMode_RegSimult;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_1; 
// 2 half-words one by one, 1 then 2 then 3
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_6Cycles; 
//6 or 5?
ADC_CommonInit(&ADC_CommonInitStructure);
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = DISABLE; 
// 1 Channel - why is it DISABLE?
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE; 
// Continuous Conversions
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
//ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T2_TRGO; // Ignored - why include it if ignored?
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 1;
ADC_Init(ADC1, &ADC_InitStructure);
ADC_Init(ADC2, &ADC_InitStructure); 
// Mirror on ADC2
ADC_Init(ADC3, &ADC_InitStructure); 
// Mirror on ADC3
/* ADC3 regular channel 8 configuration */
ADC_RegularChannelConfig(ADC1, ADC_Channel_8, 1, ADC_SampleTime_56Cycles); 
// PB0
/* ADC2 regular channel 5 configuration */
ADC_RegularChannelConfig(ADC2, ADC_Channel_15, 1, ADC_SampleTime_56Cycles); 
// PC5
/* ADC3 regular channel 0 configuration */
ADC_RegularChannelConfig(ADC3, ADC_Channel_0, 1, ADC_SampleTime_56Cycles); 
// PA0
/* Enable DMA request after last transfer (Multi-ADC mode) */
ADC_MultiModeDMARequestAfterLastTransferCmd(ENABLE);
/* Enable ADC1 */
ADC_Cmd(ADC1, ENABLE);
/* Enable ADC2 */
ADC_Cmd(ADC2, ENABLE);
/* Enable ADC3 */
ADC_Cmd(ADC3, ENABLE);
ADC_DMACmd(ADC1, ENABLE); 
//enable ADC1 DMA since ADC1 is the master
}
/**************************************************************************************/
static
void
DMA_Configuration(
void
)
{
DMA_InitTypeDef DMA_InitStructure;
DMA_DeInit(DMA2_Stream0); 
//Set DMA registers to default values
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&Adcdata;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)0x40012308; 
// CDR_ADDRESS; Packed ADC1, ADC2
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = 3; 
// Count of 16-bit words
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
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_Enable;
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);
/* DMA2_Stream0 enable */
DMA_Cmd(DMA2_Stream0, ENABLE);
}
/**************************************************************************************/
int
main(
void
)
{
ENTR_CRT_SECTION();
if
(SysTick_Config(SystemCoreClock/10000))
{ 
while
(1);
}
EXT_CRT_SECTION();
RCC_Configuration();
GPIO_Configuration();
ADC_Configuration();
DMA_Configuration();
/* Start ADC1 Software Conversion */
ADC_SoftwareStartConv(ADC1);
/*Turn on Backlight*/
GLCD_Backlight(BACKLIGHT_ON);
GLCD_SetFont(&Terminal_9_12_6,0x000F00,0x00FF0);
GLCD_SetWindow(10,116,131,131);
/*-------------------Display Readings-----------------------------------------*/
GLCD_PowerUpInit((pInt8U)IAR_Logo.pPicStream);
GLCD_Backlight(BACKLIGHT_ON);
while
(1){
/***** Compute Gain and Phase ****/
Adc3_avg = 0;
Adc2_avg = 0;
Adc1_avg = 0;
DelayResolution100us(10000);
for
(i=1;i<=20;i++)
{
DelayResolution100us(10000);
Adc1=(((
float
)Adcdata[0]) * 3.3)/4096; 
//voltage value
Adc1_avg = Adc1_avg + Adc1; 
//average gain
// Adc2con = (Adcdata[1] & 0x0FFF);
Adc2=(((
float
)Adcdata[1]) * 3.3)/4096; 
//voltage
Adc2_avg = Adc2_avg + Adc2;
//average phase
// Adc3con = (Adcdata[1] & 0x0FFF);
Adc3=(((
float
)Adcdata[2]) * 3.3)/4096; 
//voltage
Adc3_avg = Adc3_avg + Adc3;
//average phase
}
Adc1_avg = Adc1_avg/20;
Adc2_avg = Adc2_avg/20;
Adc3_avg = Adc3_avg/20;
//Write to LCD
GLCD_TextSetPos(0,0);
GLCD_print(
''G:%.02f''
, Adc3_avg);
GLCD_TextSetPos(7,0);
GLCD_print(
''P1:%.02f''
, Adc2_avg);
GLCD_TextSetPos(17,0);
GLCD_print(
''P2:%.02f''
, Adc1_avg);
}; 
// Don't want to exit
}

#adc #stm32 #dma

[Tesla DeLorean]

Posted on October 09, 2014 at 20:43

Where do you go to check theCDR_ADDRESS for ADC1, ADC2, and ADC3?

The

http://www.st.com/web/en/resource/technical/document/reference_manual/CD002257pdf

for the part? The data sheet of my STM32F207-SK board is located

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00237pdf

.

That has no information about your BOARD.

[lux]

Posted on October 09, 2014 at 22:34

It seems like when I change DMA_Mode from DMA_Mode_Circular to DMA_Mode_Normal, it works but the data is no longer continuous.

Also, in the reference manual it says that DMA mode 1 is used for triple mode. What does that mean?ADC_CDR is 32 bits do I have to do something special so that it takes 3 ADC values? I'm assuming that the library already does something like that for us. 

[Tesla DeLorean]

Posted on October 09, 2014 at 23:19

The manual can be pretty heavy going, you'll have to read and experiment.

I posted a triple interleave example

https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Problem%20with%20ADC%20DMA%20and%20timer&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B&currentviews=2...

.

[lux]

Posted on October 14, 2014 at 20:29

Hi Clive1, 

Thank-you so much for your reply, and showing me the correct reference manual. I was able to get triple mode working. Cheers, - Lux