Hello,
I'm working on a NUCLEO-H743ZI2 development board.
I was trying to change ADC sampling rate based on the frequency. The ADC is set to DMA mode and triggered by TIM2.
The problem is when I use "TIM2->ARR = 4800-1; " or "__HAL_TIM_SET_AUTORELOAD() ", ADC and DMA halt for a long time.
I attached a simple code that can reproduce the problem.
int main(void)
{
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_DMA_Init();
MX_USB_DEVICE_Init();
MX_TIM2_Init();
MX_ADC1_Init();
HAL_TIM_Base_Start(&htim2);
for(float freq = 100; freq <= 1000; freq += 10)
{
val = freq; // monitor this value in debug
if(freq < 500)
TIM2->ARR = 4800-1;
else
TIM2->ARR = 2400-1; // change ARR causes halt
HAL_ADC_Start_DMA(&hadc1, (uint32_t*)adc_buf, BUF_LEN);
while(!proceed)
{
//wait until adc_iteration reaches 10
}
proceed = 0;
HAL_ADC_Stop_DMA(&hadc1);
adc_iteration = 0;
}
while(1){}
}
void HAL_ADC_ConvHalfCpltCallback(ADC_HandleTypeDef* hadc)
{
adc_iteration++;
if(adc_iteration == 10)
proceed = 1;
}
void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)
{
adc_iteration++;
if(adc_iteration == 10)
proceed = 1;
}
From Freq = 100 to Freq = 490, it's pretty fast.
When Freq reaches 500, the value stays unchanged for a long time when I was monitoring it in the debug mode.
Then, from Freq = 510 to Freq = 1000, its fast again.
Is this because I'm changing the ARR registor in a bad way?
Thanks!
