https://discourse.agopengps.com/t/another-easy-way-of-determining-steer-angle/7391/2
Steering angle is the the angle of the inside wheel in a turn. The drive in a circle method does not always work properly. If you can physically measure it, and sometimes find it in the tractors manual(which you did!!!). The method with the phone app works well too.
Drive forward straight by hand as good as you can, aiming at a close tree or post helps, press WAS 0
Once you have the measured angle (40) crank your wheels to the right and hold, adjust counts per degree so the was angle matches your determined steering angle. Then crank all the way to the left, use ackermann to make the left (40) equal the right (40).
Then max steer set 1-2 degrees below the steer angle so you don’t hit your stops.
Min Motor speed is the minimum commanded to make the motor move, good place to start is 22
too low the motor never shuts off and gets hot, too high you drift offline before anything can happen.
Low motor is the speed that small offline corrections are made at, if this is too high you will overshoot the AB every time it steers to low you take forever to correct back to the line, Good place to start is 44.
High motor speed is the max rate it can command especially in uturn, it needs to be fast enough to keep up with the turn but not so fast you whip. Good place to start is 190.
P(roportional) is the multiplier for your error offline. Ive always left it on 102, values between 80-120 do not seem to do much for me. How i set this is by looking back at my row, if i can see jogs in the line its too high so I lower it until it looks smoother, very last setting touched.
Look ahead is very important 2.4 is a great place to start, turn it up till you wiggle, turn it down and you wiggle, you will notice a sweet spot in the middle.
Not sure look ahead speed gain does to much but too leave it at 1.4
side hill degree per degree of roll start with 0, move up very slowly, helps automatically turn a little up hill on sidehill.
Integral use the bare minimum you need, this is a last chance to keep you on a slope. Start with 2, slowly adjust up if having slippery slope issues. the number above the PP button shows if Integral is active and by how much.