Pulse counting

Ferberber — Tue, 15 Sep 2015 09:46:12 GMT

Hi,

I'm looking a solution for counting up to 8 channels pulse inputs without CPU interferance.

Thanks

Re: Pulse counting

EarlOrlando — Tue, 15 Sep 2015 20:48:57 GMT

Hello Ferberer,

Usually it is approached using a GPIO as the trigger source for a DMA channel and configuring a counter register (i.e. PIT or FTM) as the source address in the DMA channel and a buffer as the destination address. Unfortunately, only one signal can do this per each port so you won't be able to control 8 channels.

For 8 channels you can use the input compare feature in the FTM but you will need the CPU to store the counter values.

Also, if you are interested in the signal period or the pulse width of your signal, you can read about the dual-edge capturing mode.

I recommend you to take a look into the application note AN5142 which explains the features of the FlexTimer Module.

Best regards,

Earl.

topic Pulse counting in Kinetis Microcontrollers

Pulse counting

Re: Pulse counting