Freq measure , 2 signals on one board ?

[100]

Im using freq measure to measure rpm in a car and am getting great results but now i also need to measure road speed which will also need freq measure but im not sure how to go about this ? Im using a uno board but have some teensie 3.1 there if they would be more suitable .Any help would be appreciated , Thanks

 

[stevech]

road speed from OBD plug's info? I'd think RPM is there too - maybe that's what you're using now!
Or GPS though it's not as accurate or consistent (tunnels, etc.)

There a speed sensor signal from modern transmissions.
There's old school: glue a small magnet to driveshaft and use a hall effect sensor.

 

[100]

Unfortunately on this car there is no obd plug and what im after is a accurate quick signal for each , Theres no problem getting the signals or getting freq measure to read them its just im not sure how to measure both signals at the same time on one board .

 

[Constantin]

Unfortunately on this car there is no obd plug and what im after is a accurate quick signal for each , Theres no problem getting the signals or getting freq measure to read them its just im not sure how to measure both signals at the same time on one board .

I'd consider something simple like two interrupts on rising signals that increment the counter for each channel.

Every time the RTC_TSR turns over one tick, export both counters, log, reset the counters, and start over.