John Deere hitch control / hms button activation

Has anyone got AOG linked up the hms buttons on a John Deere, thought it would be neat to have it activate the switch, at the headland.

Any advice as to how it was done, thanks in advance! IMG_20200523_191953


i will do it also this project
i check the spare parts book and there is wire harness according the config

on 6030 premium, the wire harness is located under cap holder on the right console but also link with panel switch
hard to make a Y…

I plan to do this also, was just going to interrupt the the switches, connected to relays, and just use machine control board to trigger the relays…

i rewrite my previous post

i open the console and i say bad thing

i continue my investigation

I will share some picture:

The switch are on PCB! * platine_m

The PCB is not easy and i cannot find some contact by pressing the switch

  • bonus the original autoguidance switch exist but hiden by the box …

so finally it looks more complex than expected

Yeah that looks pretty complex! How did you get to that panel? I saw there were two screws that could be undone, but they didn’t seem to allow my hitch controller to come apart?

to get it not a lot of solution i disasemble it

finaly i reassemble it
if i found the conncept i probably weld some wire but unfornatly so much complex :unamused:
i dont want to kill the switch

Does that board not terminate to cables? or is it canbus?

The board terminate by 9 cable

one brown “potbrn” (probably shield ) is connected to the potentiometer and reshare (6131) to switch panel

There is LED for light also
sorry i missed to make more photo

The neates way would be isobus reading / writing.
Will start this project next winter…

In the John Deere 6930 I have stripped the hitch controller down. There are dome pcb buttons for lifting up and down and also HMS ITEC headland management buttons.

In the photos I have annotated with red where I think I may be able to control the switch with a relay.
Does anyone have experience of wiring into this type of switch?
It has a film over the top of it, to keep the switch in place so I can’t test with a multimeter without going past a point of no return.

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Yes it should work. All the dome does is short the contacts together. Usually the single trace that is near your red marks is the signal, and the dome itself is the other contact (it’s attached to the common copper you see around on either side of the signal trace). So your relay would connect the center trace with the surrounding copper to fire the button. Most likely the signal trace is held high (say 5v), and the dome would be ground.

To be clear, don’t remove the dome. Just clear the coating off of the trace and the copper the dome is attached to and solder at those points.

Google Photos
From what you have said, I take it this would be a better view of where to put my wires.

I will try first with the redundant John Deere GPS switch, that way if it goes wrong I’ve not lost the ability to use the tractor.
If it works I can use the standard steer switch as aog steer switch.

If you are lucky, the button does short common and one of the wires at the end directly. You could measure which. Or maybe at the testpoints TP1 to TP5

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Yes that looks like it will work nicely. And it’s non-destructive. You can test for continuity at those points before your solder anything. If you push the dome you should get continuity. This will definitely work for a relay controlling the tractor button from AOG. The relay provides isolation and emulates the button click.

For hooking the button to AOG, it’s more complicated. These are logic-level buttons, so the armrest controller is applying 5v to the signal wire, which is then shorted to ground to activate it. You probably could take that signal wire and go directly to an arduino input provided you have a common ground between the arduino and the armrest. But really you should have some isolation there to protect the armrest controller and the arduino from each other. Possibly an opto-isolator directly on the signal wire would work. But depending on the current capabilities of whatever is controlling the button, you might need a transistor to amplify it to run an opto-isolator.

Or you could cut the signal trace so arduino is completely in control of the button.

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So if 5v on signal wire when not activated, and 0v when active, then cut wire and insert relay that is closed in normal position, and then nano make it switch to other side with perhaps 1000 ohm resistor to common, could do the trick?

If your goal is to trigger the button using a relay, then nothing should be cut at all. The normally-open relay will just connect the signal trace to the outer copper. The relay just shorts across the button contacts which you can leave in place. No resistors needed in this case. And the original buttons still work. If you use a relay already designed to be controlled by a logic signal, then you don’t need any special driving circuitry to connect the nano to the relay coil.

If the signal wire is high and goes low (you’ll have to use a multi-meter to be sure), and if you want to have the GPS button be “read” by the Nano, that’s when you need the opto-isolator, or may need to cut the trace. Cutting the trace will make the button not work at all to the normal armrest controller anymore.

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Thanks that makes it crystal clear, I think i will just use the relays and machine module to trigger hms.
I’ll leave using the the buttons to activate AOG functions for when I run out of tings to do :slight_smile:
Just have to wait for a quiet time to dismantle the hitch controller again, busy spraying and fertiliser spreading… actually excited for some wet weather days!!!
I’ll post my progress!

I wanted to ask you a question about this. First my idea is to do the same as Seelsy with some differences: my JD 00 series has no PCB in the implement controller, only a switch with 3 wires: common, up and down. The button switchs up or down with the common. had thought to use a 4N33, which I would including in my PCBv2 modification instead of a relay. Is this possible? If not, what could I use on my PCB for this purpose (drive the implement from AOG nothing else).

Is the common wire ground and the up/down wires at some voltage? If so that should work fine. Tie the emitters to the common, and the collectors to the up/down wires.

If the common wire is at some voltage (say 12V), then you’ll need someone more knowledgeable than I am to set up a circuit with the optocoupler. Usually NPN-style transistors are not designed to have a load on the emitter. (But a relay would still work fine here.).