Is there a way to read PWM input signals? We never got our FIRST provided accelerometer, and the one from last year works rather crappily… so we’re experimenting with other ones. One I found has a PWM output signal, but I can’t figure out what I should use to measure the signal appropriately. I have a feeling its in the counter object, but I’m not quite sure…
Thanks!
You’ll probably want to use an AnalogChannel of Accelerometer object. The counter is for monitoring digital inputs and when analog inputs cross a certain threshold. Since an accelerometer outputs an analog voltage relative to how much acceleration it’s detecting, this wouldn’t be that useful.
Also, make sure your electronics are competition legal–I know for a fact that last year’s sensors are not, since they’re custom parts.
Its not the FIRST accelerometer – its output is a PWM signal, not an analog voltage.
Useful information in this thread: http://forums.usfirst.org/showthread.php?t=12086
You could try adding a capacitor on the PWM signal line to act as a low-pass filter, and then run it into an analog input.
Or you could run the PWM signal into a digital input and use change notification (interrupt on logic level change). I did this to decode a PPM signal on a PIC micro and it works great.
Nathan
An RC lowpass filter may do the trick.