I have seven adc channels to convert using STM32F051. I set the ADC to be triggered by timer 15. I also setup DMA to put all the converted results to a memory buffer and have a Transfer complete interrupt set.
Here is the setting:
Timer 15 using 100KHz
ADC set to complete whole sequence
DMA in circular mode
Everything work except that when I toggle a I/O inside the DMA interrupt, I got the frequency around 5KHz.
Any direct correlation between this 5KHz with my timer 100KHz? The MCU specification has a diagram showing that during the conversion the timer trigger will be ignored until all the conversion is complete. Does it mean that there is no way to control the sampling rate????