I am working on project that which I need to employ two adc channels with different sampling rates over STM32F4x. The first channel where I need to monitor DC voltage (Vbat) with minimum sampling rate. While, the other channel I will use to pick up ECK with sampling rate about 1Khz. I have a problem with the CPU load which I am intending to solve using the DMA.
My problem is that I need only DMA for the ADC channel while the I dont it for monitoring the VBAT. How I will be able to use 2 channels of ADC with different sampling rates?
Most of the f4 UC have more than one ADC converter. Just use one for the Vbat and the second one for the high frequency monitoring.
Another option is to start injected conversion for the Vbat - what the injected conversion is - read the Reference Manual