Building and hooking up a section control ability to a John Deere sprayer with AOG V4


  • auto on/off by a hardware switch
  • in auto off mode: turning on/off the sections by the original section switches and marking the status in AOG.
  • in auto on mode: AOG can turn on/off the sections by relays.
  • in auto on mode: If a section is turned off by AOG, it is possible to oversteer manually. You can then turn the section on by the original hardware section switch, this will marked in AOG.
  • if a relay or something will be damaged then unplugg the board, and sprayer will work as before.

Thanks for the help, I got. From Matthias Hammer, then I stole arduino code from Brian (from the usb-machineControl-ino), and thanks for the tips I got from some guys in the “Arduino für Landwirte” and “AGOpenGPS Nutzer” telegram groups.
Maybe somebody find it interesting or can need it or want to improve it or get some inspiration.

It is a project in progress and it did no real work, yet!

1 Like


SectionControl4.ino (7.6 KB) Routinen.ino (2.0 KB)

Meanwhile I did some spraying work. It works very well. I didn’t recognized any problems so far. It was really cool. The steering arduino let the tractor go really straight ahead and the section arduino turned sections on/off, everything managed by AOG.

But there are two things that could be made better. First: The position of “mainSwitch” of the sprayer is not known. If automatik mode is on and I manual turn off the MainSwitch, spraying is off, but AOG don’t know it. So marking area in AOG and real spraying area are different. This has to be modified in future. The second is the thing in AOG when driving backwards.

What needs to be changed in AOG when moving backwards?

What kind of voltages are on the sprayer’s switches? Are they 12V, or are the some kind of logic-level 5v signal (shorting to ground when on perhaps)? Either way it is probably possible measure that with arduino, perhaps using an optocoupler to isolate the arduino from the built-in electronics.

When moving backwards in AOG, e.g., to start from the corner of the field, the map and the tractor are turning in AOG and the sprayer is totally at wrong place. Section control then is not usable. You can spray in manual mode but maping still is wrong till you driving forward a few meters and all rotates towards the right place.
See picture below. There where is double “painted”, I was moving backwards because I missed the tramline and had to correct.
How to solve? Maybe manipulating the heading with 180° in this case, no idea. I guess it is tougher then this.

On the sprayer’s switches are 12V voltage. Yes, I need an optocoupler. It should be doable the same way I did it with the section switches.

1 Like

on trimble if you back into corner you can hit a button on screen and flip heading 180 degrees so that you can start. :slightly_smiling_face:

Interesting. When AOG first starts, it’s unsure of where the tool actually is, so it should default to 180 degrees from the heading. But after that if you back up, the toolbar should be pushed back like a real trailer would, although it would probably jack knife differently than in real life. Maybe a quick button to force the toolbar to be straight back from the tractor, and a button to quickly reverse the heading, would do the trick for you.

AGO can drive backwards, by getting speed with neg sign. Not tested for VTG, but with paogi it worked.

In the Data Source form, Fix tab, you can set how far the distance is between fixes to calculate heading. Try setting it low enough (0.2m) but also stays within the drift limit of the gps. If you are using RTK, you can make that distance pretty small. It will react much faster

Why not working with a “reverse-contact” witch is activated, when you are driving backwards?
This could be done with an input on the arduino. Possible?

I will test it.

There is even an unused information bit. The remote pin is transmitted but unused in AOG. MTZ8302 suggest to negate the VTG speed in this case.

If you had a dual antenna, there would be no problem

I don’t know how john deere handles that. The autotrac system doesn’t operates with dual antenna neither.

Do you know which PGNS are affected on the implement bus when you spray. I would like to log my spray and gps coordinates to map my coverage. Thanks