STM32F407G-DISC1 3 ADC

[TomᨠStratil]

Posted on October 17, 2017 at 14:05

Dear STM32 community,

I am new at field of 32bit ARM, I have only little experience with 8bit Atmel chips and arduino programming. We need to replace expensive ADC card from National Instruments company by some cheaper own solution, at my university. We considered use STM32F4, because it has 3 ADCs. Our goal is to capture 3 analog signals, and do some basic matetatical operations between them. Is it possible to capture all 3 ADCs at the same time? All examples what I saw are about usage 3 ADCs for faster conversion or usage 2 ADCs for sampling voltage and current at the same time. Thanks for answer.

#adc #stm32f407g-disc1

[Tesla DeLorean]

Posted on October 17, 2017 at 14:44

You have to configure the ADC in Triple Mode, this ties them together so they sample at the same instant.

You can trigger them with one TIM source, and read the values with one DMA unit.

[LMI2]

Posted on October 17, 2017 at 16:51

What is the resolution of that NI card? Basic ADCs in STM32 are 12 bit wide. Audio ADCs may have more. What about incoming signal conditioning, filtering and protecting the rest of the circuit. Cheap ADC may become a costly

signal acquisiotion card. But of course more fun and educational.

[Tesla DeLorean]

Posted on October 17, 2017 at 14:51

 ,

 ,

You'd want to change to use , ,ADC_TripleMode_RegSimult in this example

 ,

[TomᨠStratil]

Posted on October 18, 2017 at 10:31

Resolution of that NI card is 16 bit, but 12 bit resolution in STM32 would be ok for us, but we need to test it more. That NI card has only 500 kS/s, ADCs in STM32F4 with 2,4 MS/s would be interesting. We need to make external protection and additional signals adjusting of course.

Thanks for reply.

[AvaTar]

Posted on October 18, 2017 at 10:38

The F4 discovery is designed as a (cheaper) general-purpose evaluation board, and not especially for analog applications.

This means, the theoretical 12-bit resolution will not be achieved in reality.