Showing results for 
Search instead for 
Did you mean: 

Selecting a STM32 MCU

Donnie B
Associate II


Thank you for having me here! I come from the AVR-Mega community and wondering about selecting a STM32 MCU. I needed more time to process between my input capture and USART and HDLC processing. Which MCU have 4 timers and input/output capture available? something a beginner can get a understanding of whats going here with STM32. I feel like I'm in deep water right now ooking for a Nucleo Board.

thank you



What do you mean by "input/output capture"?

Probably all STM32 have at least 4 timers; the question is only whether enough pins from them are brought out for your particular purpose.



PS. Please change your username to a normal nick.

I'm not even sure if I know enough yet about STM32 but on AVR MCU I'm using input capture so an interrupt is generated on say rising edge save that time reconfigure timer for falling edge and subtract the 2 times to determine the pulse with on the GPIO pin. Output compare the MCU generates the timing of the pulse .

You can get the processor to interrupt/latch on either/both edges (for the most part), you can also cross-feed (indirect) onto a second channel such that one pin can latch CH1 and CH2 on opposite edges.

Also there is a PWM Input mode, pairing CH1/CH2 and reset such that you can get one interrupt and compute Period and Duty, or just read the registers to see the most current measurement.

The TIM are probably the most complex part of the STM32 design.

Remember there is a single counting element, and four latches to either capture the current count, or trigger on a count comparison. You can mix channels between capturing or comparing.

Tips, Buy me a coffee, or three.. PayPal Venmo
Up vote any posts that you find helpful, it shows what's working..

Thanks Clive Two.Zero, So I see some of these can have 4 either setup for input capture or output capture. The data I'm working with is a 9600 baud synchronous serial stream and it's encode with HDLC I have a AVR-Mega32 decoding it just fine having a blast getting that working. I'm using the input capture to process the clock and reading the data on rising edge. Don

Awesome I installed the MCU Finder on my tablet

Thank you Bryan


Hi @Bryan SPEED​  ,

I see you are an ST employee. Can you please explain, why exactly can't this selector be online?


Jan Waclawek