roboRIO USB Host Port Communications

Technical Electrical
1

So I know questions about the roboRIO USB host ports have been asked before, but my team is considering receiving unconventional input (from a custom circuit with a “sensor”) into the roboRIO via the USB ports. The thing is looking around manuals and other threads makes it seem that not any device works for this. The NI manual seems to limit things to cameras, flash drives, and USB-IDE adapters, but I’ve also seen things like Arduinos work.

Now of course I could just use the RS-232 port, but that’s super annoying because it requires a negative voltages, while USB is 0-5 V.

I could also use the Digital I/O ports and write some code to process that into Serial but I would rather use the preexisting library which supports communications only for USB, MXP, and RS-232.

2

Since you point to the SerialPort class, do you just want a TTL serial port to hook up to your custom circuit? Or are you trying to do something more advanced? The MXP port uses 0-5V TTL level serial (rather than RS-232). If you want a TTL serial port via USB, something like this SparkFun USB-TTL cable should do the trick.

3

I’m not an expert, but all I know is that the custom circuit is built to output either 0 V or 5V with NRZ encoding and UART protocol. I think this should work as TTL serial port via USB, but please tell me if it won’t. Thanks for the help!

4

Yes, that should work as a TTL serial port via a USB-TTL serial converter like the one I linked to or via the MXP port.

5