I am assuming you mean a 2 track machine? I think the only way on one of those would be a rotary encoder on the steering column.
Its a Deere 8420T tractor. I pulled a generic picture off the internet. A wheeled tractor would be easy. Just not sure how to deliver steering information to AGOpenGPS on a track tractor.
I'm not sure if the deere's wheel returns to the same position or not. I know the newer challenger two tracks do.I am assuming you mean a 2 track machine? I think the only way on one of those would be a rotary encoder on the steering column.
That would work for sure if the wheel always returns to the same position - like a car. A rotary encoder would work.
For example - https://www.amazon.ca/BQLZR-Incremental-Encoder-DC5-24V-Voltage/dp/B00IJ788AA/ref=asc_df_B00IJ788AA/?tag=googleshopc0c-20&linkCode=df0&hvadid=292939036793&hvpos=1o4&hvnetw=g&hvrand=1173513105318059123&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9001283&hvtargid=pla-615629358875&psc=1