John Deere ATU 200

Can a John Deere ATU 200 (auto trac universal) be used be used as a steering motor with agopengps system? Can’t find any technical info on them?

I think it can. You just need to find the correct pins for the motor, as well for the steering angle sensor, I think it is built inside the ATU Motor. I will try it out, but currently I have no time for it.
I will update you when I do something with that.

I found the wiring harness pinout for the ATU.

Check page 141.
You will need to install your WAS but you can use the motor.

CAN Hi
CAN Lo

I think you need to use those pins. Try it out and update us please.

Best regards,
Marko

we also have an ATU 200
but for the moment we have replaced the original motor by another DC motor (easier to drive) but the gearbox is difficult to turn at no load.
We will be happy to find a solution that allows the original engine to be used.
I feel like it’s a Can-Bus piloting ? It’s hard to use.
What about the supply voltage? 12V ? 24V ?

I don’t think that the angle sensor is integrated in the motor, for example, if you turn your wheels to the maximum, then the steering wheel keeps turning while the wheels keep the same angle, it would distort the value given by the motor if it was used as a wheel angle sensor.

At Trimble there is a calibration to be done for the electric steering wheel: on a straight line AB the steering wheel turns 5°, for example, and it calculates the angle of the wheels according to the tractor’s heading in relation to line AB. Thanks to this, the autosteer knows that with a 5° steering wheel turn for example, it knows that it can deviate 25° from its guiding line.
It works for Trimble, I don’t know about John Deere.

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@clement.hegron

You can simply check the voltage coming out from the other side of the plug. Try too disconnect the ATU and then set up some AB lines and check the voltages coming out from the GreenStar side of the plug. Then you will now the voltage as well which pin does what for sure. If it can not register the ATU and it wont start try to short two pins in the plug. You need to play around with it. But you can make it work 100%.

Best regards,
Marko

@markonovic00
except we bought the steering wheel especially for AOG. :sweat_smile:
We don’t have a John Deere console and antenna, so we would have been happy to do all these tests but we can’t

@clement.hegron
You can check the PDF that I posted earlier, there is the wiring diagram you can try it with 12 volts.

@markonovic00

is it possible for the engine to run if there is no information from the can bus?

@clement.hegron

It is a simple DC Motor, you just need to figure out which wire is doing what, and you are good to go.
Maybe try to control it with the IBT2 as well, use some simple code from the internet and wiring schematics and try it, 12V can not hurt the DC motor.
I don’t understand what you mean by no information from the CAN BUS.

The ATU does not need to be connected to a John Deere tractor, I run my own on a Fendt 716 with a GreenStar 2600 monitor, it is doing great. But it is only unlocked for the SF2, I want to install RTK correction in all my tractors. I am interested as well in this topic, because the mount and the motor is there.

@markonovic00

what I meant: when I saw your document on plugs and their association, I saw CAN
and then I misspoke when I said BUS-CAN (I mixed up all these notions).

I’ve already seen how work a John Deere autosteer with an electric steering wheel

If I summarize, the 2 pins CAN HI and CAN LOW are not used to run the engine?
They just send information back to the green star?
We saw on the Schneider documentation that it was a stepper motor, so I deduce that we did not have the right documentation.

@clement.hegron

Sorry, I did a little bit of a research and it is a stepper motor. You can get a stepper motor controller instead of an IBT2 and run it with that. You will need to change the code a little bit, but it is still possible.

Hello,

I don’t have an ATU, but when I see the pin description on the document post above:

  • 4: CAN Hi
  • 5: CAN Low
  • 7: Switched power
  • 5: Ground

It seems that the ATU input setpoint is a CAN message, coming from a CAN bus.
So my hypothesis is that the ATU is not a simple motor, but a motor with his associated micro controleur unit (MCU).
So I guess that the MCU receive the engine setpoint from the console throught the CAN bus and base on it, drive the motor with the appropriate motor control signal. The power probably came from the PIN 7 (12,5V according to this document: https://stellarsupport.deere.com/site_media/pdf/fr/manuals/ATU/OMPFP11846_28_B2_PG_FRE_ATU.pdf). The MCU could generate the appropriate motor control signal from this power supply.
It seems risky to me to directly inject 12V PWM signal on the CAN Hi and CAN Low input if your aren’t sure what is there behind this pins: if it’s the MCU CAN input, you will probably burn it.

If you can’t find technicals details on the ATU and architecture, in my opinion, the best way is to do is to disassemble it and try to identify the electrical architecture and componants:

  • Can you identifie a separate MCU and a motor ? If not, you cannot exclude that the controleur is integrated to the motor
  • Can you identifie the moteur type: It could be a DC motor that is controled with PWM. But you could also imaginate that it’s a stepper motor or a Brushless DC motor: in this case, the way to control it is a little bit more complicated and you cannot drive it with a IBT2 or a MD13S

Hop it could help.

Math

@Math

I agree with you. The best way is to disassemble it and see what is behind the covers. It is a stepper motor for sure, that is in their documentation.

Best regards,
Marko

So, pretty sure that there is a microcontroleur unit that receive motor setpoint througth the can bus and transform it into stepping commant to the motor.

Math

@markonovic00
@Math

@clement.hegron

Best way of doing this is to bypass the ATU controller and to use a Stepper Motor driver instead of a IBT2, they are pretty much the same thing just the IBT2 is for DC motors and on the market you can find lots of stepper motor drivers.

I can make the changes in the code, but I don’t have the time now, I will test it probably during the summer, because I need the tractor right now.

You mentioned that you are using it with a DC motor, right?

Best regards,
Marko

that’s what we tried to do with that Driver

We noticed a lack of power, perhaps due to a low amperage because the driver was limited to 4A.

We spent many weeks on this driver and this engine, without success. Maybe our skills were limited.

So we chose to use a DC motor, but this one has a gearbox that makes it difficult to rotate the steering wheel. We can’t work like that.

We have two choices
Use a motor without a gearbox (easier to run dry).
Try again the Schneider electric motor by choosing a bigger and not too expensive driver and maybe with your help, modify the arduino code to easily drive this new driver.

@clement.hegron

I think the best solution is then to use DC motor without a gearbox. I will do it personally that way.

Best regards,
Marko

I will share our experience with you, in the meantime I will share you our current motor (the one with a gearbox).
The motor is probably too powerful compared to our needs ( 30 Nm )
The person who enlarged our gable hole did it very badly, so it doesn’t turn straight.
We are not very happy with this engine because it is not adapted to our needs, it is made to be disengaged from the steering wheel when driving on the road.

IMG_58911
IMG_58921 IMG_58931

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@clement.hegron

You don’t need a really powerful motor if the steering on the tractor is good.
You can simply measure the power of the DC motor you need, by using a digital scale, attaching it to the steering wheel and star puling until it start rotating, check how many kg is on the scale in the moment when the steering wheel starts turning. Then you can use conversion from kg to N and you will get your power. It will not be accurate but you can get a good idea.

Best regards,
Marko

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The ATU was converted to use a gear motor but how does it disengage when manual steering is desired?