Autosport Labs

I'm having trouble using the digital outputs of my RaceCapturePro2.

I set the three digital outputs to output mode.

I wrote a script to toggle one of the digital outputs between on and off once per second.

When I put my multimeter probes on the 5v reference and the digital output, the voltage changes from 0 to 5 and back every two seconds, as expected.

However, when I put my multimeter probes on the ground and the digital output, the voltage always reads 0.

When I set two different digital outputs to different values, the voltage between them always reads 0.

Is this expected or am I doing something wrong?

When I did the same test on an Arduino, everything works as I would expect. I'm able to read the voltage between the outputs and the ground. I'm also able to control an external device with the Arduino that I would like to control with RaceCapturePro2. The device connects to ground, 5v reference, and three digital outputs.

Hi,

The output are working as expected. See the specs here:
https://wiki.autosportlabs.com/RaceCapt ... ifications

The outputs are open drain that switch to ground when activated, and are an open circuit when not activated.

A classic way to use the outputs is to activate an accessory, light, relay in the following way:

12v ---- (+) (device) (-) --- RaceCapture/Pro GPIO output

Hope this helps!

Thanks Brent,

I understand how this could be used to connect an output to one or more LEDs.

In my case, I'm trying to use the outputs as inputs to a microcontroller that controls a larger number of independent LEDs. I'm connecting the three digital outputs, the 5v reference, and the ground to the device.

Based on your reply, I think I would need something like this:
Does this look right?
Any advice about what kind of relay I would need?

You can simulate the 0-5v signal you need by tying our GPIO output to a pullup resistor to 5v, on your arduino side.

Thanks, Brent.

This worked fairly well.

In hindsight, using the digital outputs probably wasn't the best choice for high speed communication between the RaceCapturePro2 and the Arduino. I would probably have better luck using the aux serial connection to transfer information at a faster rate.

I noticed I had to wait a couple of ticks after setting one of the digital outputs before I could set it again to a different value.

Glad you got it working. Yes, CAN or RS232 serial might be better options!