Can the OnTrac 2+ accept GPS from an external source and use it for steering? Is there a serial input port on the OnTrac? EDIT: I think so. The manual states it's compatible with most GPS receivers, so as long as you give it the proper NMEA sentences, it should go.
I believe the ArduSimple kit can probably work for you but will require some assembly. What I mean is that it's just a bare board. You'll have to put it in an enclosure, and provide a TTL to RS232 converter to convert the serial output to RS232 to feed into the OnTrac. Also you'll have to use the u-center computer program (which is a bit hard to use) to configure it to output the NMEA strings that the OnTrac requires (which I don't know but could guess at), and set the serial port speed.
The base station unit will need a bit of configuration as well to enable survey-in mode (or if it's never going to move, fix it's coordinates).
If you can do this, or get someone to help sit down with you and set it up, it could work!
Last edited by torriem; 07-10-2019 at 12:41 AM.