ADC trigger on timer update

[alexpabouct9]

Posted on August 27, 2013 at 11:24

Hello,

I'm currently working on a brushless motor control application and i'm in the process of implementing the current measuring of the three phases. In order to do so, I need to synchronise the ADC sampling with the PWM outputs in order to sample at the center of the PWM outputs (center aligned 2 mode).Unfortunately cannot find a simple solution. From the datasheet i see that the ADC can be trigger by either the CC1-4 timer interrupts or the TRGO interrupt. However, from what i've read, the interrupt that that the ADC needs to trigger off of is the timer update interrupt (which is not in the list of available ADC triggers external triggers).Am i understanding this correctly? I was expecting a straightforward solution as this is a common problem in any motor control application, which is one of the mains features of the advanced timers.Thanks,Alex #stm3-adc-trigger

[Tesla DeLorean]

Posted on August 27, 2013 at 15:33

Am i understanding this correctly?

You appear to be making things more complicated than they are. No, you're not limited to the Update, but you have specific timers and channels that are usable. In fact to use the Update you'd have to select that as a TRGO output, then select that as a trigger input to the ADC. You don't specify a part, so for the F4 we have the following options:

/** @defgroup ADC_extrenal_trigger_sources_for_regular_channels_conversion
* @{
*/
#define ADC_ExternalTrigConv_T1_CC1 ((uint32_t)0x00000000)
#define ADC_ExternalTrigConv_T1_CC2 ((uint32_t)0x01000000)
#define ADC_ExternalTrigConv_T1_CC3 ((uint32_t)0x02000000)
#define ADC_ExternalTrigConv_T2_CC2 ((uint32_t)0x03000000)
#define ADC_ExternalTrigConv_T2_CC3 ((uint32_t)0x04000000)
#define ADC_ExternalTrigConv_T2_CC4 ((uint32_t)0x05000000)
#define ADC_ExternalTrigConv_T2_TRGO ((uint32_t)0x06000000)
#define ADC_ExternalTrigConv_T3_CC1 ((uint32_t)0x07000000)
#define ADC_ExternalTrigConv_T3_TRGO ((uint32_t)0x08000000)
#define ADC_ExternalTrigConv_T4_CC4 ((uint32_t)0x09000000)
#define ADC_ExternalTrigConv_T5_CC1 ((uint32_t)0x0A000000)
#define ADC_ExternalTrigConv_T5_CC2 ((uint32_t)0x0B000000)
#define ADC_ExternalTrigConv_T5_CC3 ((uint32_t)0x0C000000)
#define ADC_ExternalTrigConv_T8_CC1 ((uint32_t)0x0D000000)
#define ADC_ExternalTrigConv_T8_TRGO ((uint32_t)0x0E000000)
#define ADC_ExternalTrigConv_Ext_IT11 ((uint32_t)0x0F000000)

[Tesla DeLorean]

Posted on August 27, 2013 at 15:42

// STM32 ADC Sample @ 200 KHz (PC.1) STM32F4 Discovery - sourcer32@gmail.com
// Assumptions per system_stm32f4xx.c CPU @ 168 MHz, APB2 @ 84 MHz (/2), APB1 @ 42 MHz (/4)
#include ''stm32f4_discovery.h''
/**************************************************************************************/
void RCC_Configuration(void)
{
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
}
/**************************************************************************************/
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* ADC Channel 11 -> PC1
*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
GPIO_Init(GPIOC, &GPIO_InitStructure);
}
/**************************************************************************************/
void ADC_Configuration(void)
{
ADC_CommonInitTypeDef ADC_CommonInitStructure;
ADC_InitTypeDef ADC_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);
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = DISABLE; // 1 Channel
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE; // Conversions Triggered
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_Rising;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T2_TRGO;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 1;
ADC_Init(ADC1, &ADC_InitStructure);
/* ADC1 regular channel 11 configuration */
ADC_RegularChannelConfig(ADC1, ADC_Channel_11, 1, ADC_SampleTime_15Cycles); // PC1
/* Enable DMA request after last transfer (Single-ADC mode) */
ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);
/* Enable ADC1 DMA */
ADC_DMACmd(ADC1, ENABLE);
/* Enable ADC1 */
ADC_Cmd(ADC1, ENABLE);
}
/**************************************************************************************/
#define BUFFERSIZE 400 // 200KHz x2 HT/TC at 1KHz
__IO uint16_t ADCConvertedValues[BUFFERSIZE];
static void DMA_Configuration(void)
{
DMA_InitTypeDef DMA_InitStructure;
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADCConvertedValues[0];
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = BUFFERSIZE; // 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);
/* Enable DMA Stream Half / Transfer Complete interrupt */
DMA_ITConfig(DMA2_Stream0, DMA_IT_TC | DMA_IT_HT, ENABLE);
/* DMA2_Stream0 enable */
DMA_Cmd(DMA2_Stream0, ENABLE);
}
/**************************************************************************************/
void TIM2_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
/* Time base configuration */
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
TIM_TimeBaseStructure.TIM_Period = (84000000 / 200000) - 1; // 200 KHz, from 84 MHz TIM2CLK (ie APB1 = HCLK/4, TIM2CLK = HCLK/2)
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
/* TIM2 TRGO selection */
TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update); // ADC_ExternalTrigConv_T2_TRGO
/* TIM2 enable counter */
TIM_Cmd(TIM2, ENABLE);
}
/**************************************************************************************/
void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
/* Enable the DMA Stream IRQ Channel */
NVIC_InitStructure.NVIC_IRQChannel = DMA2_Stream0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/**************************************************************************************/
void DMA2_Stream0_IRQHandler(void) // Called at 1 KHz for 200 KHz sample rate, LED Toggles at 500 Hz
{
/* Test on DMA Stream Half Transfer interrupt */
if(DMA_GetITStatus(DMA2_Stream0, DMA_IT_HTIF0))
{
/* Clear DMA Stream Half Transfer interrupt pending bit */
DMA_ClearITPendingBit(DMA2_Stream0, DMA_IT_HTIF0);
/* Turn LED3 off: Half Transfer */
STM_EVAL_LEDOff(LED3);
// Add code here to process first half of buffer (ping)
}
/* Test on DMA Stream Transfer Complete interrupt */
if(DMA_GetITStatus(DMA2_Stream0, DMA_IT_TCIF0))
{
/* Clear DMA Stream Transfer Complete interrupt pending bit */
DMA_ClearITPendingBit(DMA2_Stream0, DMA_IT_TCIF0);
/* Turn LED3 on: End of Transfer */
STM_EVAL_LEDOn(LED3);
// Add code here to process second half of buffer (pong)
}
}
/**************************************************************************************/
int main(void)
{
RCC_Configuration();
GPIO_Configuration();
NVIC_Configuration();
TIM2_Configuration();
DMA_Configuration();
ADC_Configuration();
STM_EVAL_LEDInit(LED3); /* Configure LEDs to monitor program status */
STM_EVAL_LEDOn(LED3); /* Turn LED3 on, 500 Hz means it working */
/* Start ADC1 Software Conversion */
ADC_SoftwareStartConv(ADC1);
while(1); // Don't want to exit
}

[alexpabouct9]

Posted on August 27, 2013 at 16:06

This helped alot, thanks!

Cheers,Alex

[sh2]

Posted on September 23, 2014 at 18:01

Hello,

I try to measure the voltage on ADC1_0, ADC2_1, ADC3_2, ADC1_10, ADC2_11 and ADC3_12 in TripleMode_RegSimult, but a still have problems to set correctly the sampling frequency. I use TIM2 for setting the sampling frequency as shown in the example above. I also use DMA in double buffer mode to put the ADC data into two buffers. If one of the two buffers becomes full the DMA generates interrupt. Inside the interrupt service routine I toggle a pin in order to measure how fast the buffer is felt. I have observed that regardless of the value in TIM_TimeBaseStructure.TIM_Period the sampling frequency respectively the time measured by the toggled GPIO time remains constant ca. 268ms. I use STM32f407VGT on costume board (not discovery) with APB2CLK=83,174MHz. The DMA buffers are 32KByte each. How to set the sampling frequency?? I need sampling frequency at ca. 40KHz. Check my code from the attachments. best regards ________________ Attachments : adcsamplinPost.txt : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I1M5&d=%2Fa%2F0X0000000blm%2FunMINg2Xfi.tm9UoHyY2GTu79LRjLpZDQd8K.maxA18&asPdf=false

[Tesla DeLorean]

Posted on September 23, 2014 at 22:20

This seemed to work for me.

// STM32 ADC Triple Six Sample @ 40 KHz (PA.0, PA.1, PA.2, PC.0, PC.1, PC.2) STM32F4 - sourcer32@gmail.com
// Assumptions per system_stm32f4xx.c CPU @ 168 MHz, APB2 @ 84 MHz (/2), APB1 @ 42 MHz (/4)
// Pin conflicts on Discovery, using as a test vehicle
#include ''stm32f4_discovery.h''
/**************************************************************************************/
void RCC_Configuration(void)
{
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOA | RCC_AHB1Periph_GPIOC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_ADC2 | RCC_APB2Periph_ADC3, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
}
/**************************************************************************************/
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* ADC Channel 0 -> PA0 ADC123_IN0
ADC Channel 1 -> PA1 ADC123_IN1
ADC Channel 2 -> PA2 ADC123_IN2
ADC Channel 10 -> PC0 ADC123_IN10
ADC Channel 11 -> PC1 ADC123_IN11
ADC Channel 12 -> PC2 ADC123_IN12
*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_Init(GPIOC, &GPIO_InitStructure);
}
/**************************************************************************************/
void ADC_Configuration(void)
{
ADC_CommonInitTypeDef ADC_CommonInitStructure;
ADC_InitTypeDef ADC_InitStructure;
/* ADC Common Init */
ADC_CommonInitStructure.ADC_Mode = ADC_TripleMode_RegSimult;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_1; // 3 half-words one by one, 1 then 2 then 3
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
ADC_CommonInit(&ADC_CommonInitStructure);
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = ENABLE; // 2 Channels
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE; // Conversions Triggered
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_Rising;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T2_TRGO;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 2;
ADC_Init(ADC1, &ADC_InitStructure);
ADC_Init(ADC2, &ADC_InitStructure); // Mirror on ADC2
ADC_Init(ADC3, &ADC_InitStructure); // Mirror on ADC3
/* ADC1 regular channel 0 & 10 configuration */
ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_15Cycles); // PA0
ADC_RegularChannelConfig(ADC1, ADC_Channel_10, 2, ADC_SampleTime_15Cycles); // PC0
/* ADC2 regular channel 1 & 11 configuration */
ADC_RegularChannelConfig(ADC2, ADC_Channel_1, 1, ADC_SampleTime_15Cycles); // PA1
ADC_RegularChannelConfig(ADC2, ADC_Channel_11, 2, ADC_SampleTime_15Cycles); // PC1
/* ADC3 regular channel 2 & 12 configuration */
ADC_RegularChannelConfig(ADC3, ADC_Channel_2, 1, ADC_SampleTime_15Cycles); // PA2
ADC_RegularChannelConfig(ADC3, ADC_Channel_12, 2, ADC_SampleTime_15Cycles); // PC2
/* 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);
}
/**************************************************************************************/
#define BUFFERSIZE (40 * 6 * 2) // 40KHz x6 x2 HT/TC at 1KHz
__IO uint16_t ADCTripleConvertedValues[BUFFERSIZE]; // Filled as pairs ADC1, ADC2, ADC3
static void DMA_Configuration(void)
{
DMA_InitTypeDef DMA_InitStructure;
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADCTripleConvertedValues[0];
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)0x40012308; // CDR_ADDRESS; Packed ADC1, ADC2
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = BUFFERSIZE; // 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);
/* Enable DMA Stream Half / Transfer Complete interrupt */
DMA_ITConfig(DMA2_Stream0, DMA_IT_TC | DMA_IT_HT, ENABLE);
/* DMA2_Stream0 enable */
DMA_Cmd(DMA2_Stream0, ENABLE);
}
/**************************************************************************************/
void TIM2_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
/* Time base configuration */
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
TIM_TimeBaseStructure.TIM_Period = ((SystemCoreClock / 2) / 40000) - 1; // 40 KHz, from 84 MHz TIM2CLK (ie APB1 = HCLK/4, TIM2CLK = HCLK/2)
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
/* TIM2 TRGO selection */
TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update); // ADC_ExternalTrigConv_T2_TRGO
/* TIM2 enable counter */
TIM_Cmd(TIM2, ENABLE);
}
/**************************************************************************************/
void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
/* Enable the DMA Stream IRQ Channel */
NVIC_InitStructure.NVIC_IRQChannel = DMA2_Stream0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/**************************************************************************************/
void DMA2_Stream0_IRQHandler(void) // Called at 1 KHz for 40 KHz sample rate, LED Toggles at 500 Hz
{
/* Test on DMA Stream Half Transfer interrupt */
if(DMA_GetITStatus(DMA2_Stream0, DMA_IT_HTIF0))
{
/* Clear DMA Stream Half Transfer interrupt pending bit */
DMA_ClearITPendingBit(DMA2_Stream0, DMA_IT_HTIF0);
/* Turn LED3 off: Half Transfer */
STM_EVAL_LEDOff(LED3);
// Add code here to process first half of buffer (ping)
}
/* Test on DMA Stream Transfer Complete interrupt */
if(DMA_GetITStatus(DMA2_Stream0, DMA_IT_TCIF0))
{
/* Clear DMA Stream Transfer Complete interrupt pending bit */
DMA_ClearITPendingBit(DMA2_Stream0, DMA_IT_TCIF0);
/* Turn LED3 on: End of Transfer */
STM_EVAL_LEDOn(LED3);
// Add code here to process second half of buffer (pong)
}
}
/**************************************************************************************/
int main(void)
{
RCC_Configuration();
GPIO_Configuration();
NVIC_Configuration();
TIM2_Configuration();
DMA_Configuration();
ADC_Configuration();
STM_EVAL_LEDInit(LED3); /* Configure LEDs to monitor program status */
STM_EVAL_LEDOn(LED3); /* Turn LED3 on, 500 Hz means it working */
/* Start ADC1 Software Conversion */
ADC_SoftwareStartConv(ADC1);
while(1); // Don't want to exit
}
/**************************************************************************************/
#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

'', file, line) */
/* Infinite loop */
while (1)
{
}
}
#endif
/**************************************************************************************/

[sh2]

Posted on September 24, 2014 at 11:34

Hello,

it tested your code on my discovery board and it doesn't work for me. The led toggles with a frequency of 100Hz. My clocks are correctly configured: SystemCoreClock = 168MHz, APB1=42MHz, APB2=84MHz.Can you provide your SystmInit code. I also noticed, that you assumed, that TIM2 runs at SystemCoreClock / 2 = 84MHz. Why? Tim2 is on the APB1 so it must run at 42MHz?? 

[sh2]

Posted on September 24, 2014 at 12:08

OK I fix it. The problem was that the my systemInit was not called. 

On the other hand, it is still interesting for me, why TIM2 runs on 84MHz and not on 42MHz?

[Tesla DeLorean]

Posted on September 24, 2014 at 14:17

TIMCLK is APBCLK*2 in all cases except DIV1, review the Reference Manual, Clock Tree

[r2s]

Posted on February 12, 2016 at 16:24

Hi Clive,

In your example you use timer 2 (ADC_EXTERNALTRIGCONV_T2_TRGO) as external tigger for ADC conversion. I don't unserstand the other triggers (ADC_EXTERNALTRIGCONV_T2_CC2/CC3). Does this mean that  i shall call HAL_TIM_OC_Init()  to use the appropiate trigger for ADC instead of HAL_TIM_Base_Init()?  What would have happened if timer 2 was in use by another SW module (lets say by another task that use it as a classic base timer)? I guess that the other  triggers for ADC ( ADC_EXTERNALTRIGCONV_T2_CC4/CC3) can not be used and i shall switch to a not used timer (timer 8) for example. Am I missing something ? My purpose is to hand a configurable ADC scan conversion mode with a timer as trigger (also configurable). thanks in advance