[SOLVED] How can I trigger ADC with an external clock generator on STM32 board?

[nadd]

Hello,

I'm trying to trigger ADC on the STM32F303RE Nucleo board with an external clock generator. Without external trigger settings, it works. I changed the trigger source to Timer8, then in TIM8 settings, I chose External Clock Source. What am I doing wrong? I didn't change any user codes, should I add pin up/down commands to start ADC in user code sections?

My ADC(DMA) and TIM8 settings:
(My clock(square wave) generator connected to PB6 pin)

 

[KlausST]

Hi,

Why via timer?
Can't you use EXTI line?

I've no experience with the STM32F4xx ... just used STM32F1xx devices.

Klaus

 

[nadd]

Hi,

Why via timer?
Can't you use EXTI line?

I've no experience with the STM32F4xx ... just used STM32F1xx devices.

Klaus

Hi Klaus,

In ADC's external trigger source settings, there are only timers. No other option. Because of that, I chose one of them, then I tried to use it with an external source.

 

[KlausST]

Hi,

please show the whole CubeMX window.
..with all ADC setups.

currently we can't even see which ADC you did choose.

Klaus

 

[nadd]

Hi,

please show the whole CubeMX window.
..with all ADC setups.

currently we can't even see which ADC you did choose.

Klaus

Sure, sorry for that.

 

[KlausST]

Hi,

please scroll down the MODE window (section).

Klaus

 

[nadd]

There is only an "independent mode" available.

 

[KlausST]

Hi,

Do you need help?

Klaus

 

[nadd]

Hi,

Do you need help?

Klaus

Hi,

Yes, I need help.


I save the data to a size of 12000 buffer, then write in serial port. Without external trigger settings, it works. But, when I change "Continous Conversion Mode-Disable, External Trigger Source-Timer8", it doesn't work.


Also, briefly the user codes I use(some of the variables are for saving to an SD card):

#define ADC_BUF_LEN 12000
 
void myprintf(const char *fmt, ...) {
  static char buffer[ADC_BUF_LEN];
  va_list args;
  va_start(args, fmt);
  vsnprintf(buffer, sizeof(buffer), fmt, args);
  va_end(args);
 
  int len = strlen(buffer);
  HAL_UART_Transmit(&huart2, (uint64_t*)buffer, len, -1);
 
}
 
HAL_ADC_Start_DMA(&hadc1, (uint16_t*)adc_buf, ADC_BUF_LEN);
 
void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc) {
    for (int i = 0; i < ADC_BUF_LEN; ) {
    myprintf("%i\r\n", adc_buf[i]);
    i++;
    }

 

[KlausST]

Hi,

Yes, I need help.

Then please scroll down the MODE window and show the screenshot.

Klaus

 

[nadd]

Hi,


Then please scroll down the MODE window and show the screenshot.

Klaus

I'm so sorry, I didn't realize before that Mode window's name and there are other options there. EXTI is here, I see now. It is on "Disable"

 

[KlausST]

HI,

Set it on "Regular conversion trigger". Then see the extra pin coming up on the CHIP view.

With this external pin (EXTI) you should be able to start a single conversion or even a conversion sequence.
I never used/tried this, though.

Klaus

 

[nadd]

HI,

Set it on "Regular conversion trigger". Then see the extra pin coming up on the CHIP view.

With this external pin (EXTI) you should be able to start a single conversion or even a conversion sequence.
I never used/tried this, though.

Klaus

Hi Klaus,

Thank you so much! It works now! I've been trying all the Timer settings for a week to do this. I wish I could see EXTI earlier.

Thanks again