Massey Ferguson 7700 autosteer ready

Hello guys,

i just wanted to share my experiences with AgOpenGPS on my steering ready Massey Ferguson 7718 tractor for beginners. With Tonys (CommonRail) Arduino Program, it is no rocket science to get a working solution.
Basic wiring scheme:

Hardware and beginner issues

I recommend using an uno and a bigger can shield, because you can easily snap the shield on and you have a shock-proof connection. A nano and the little can shield might also do the job. My fake arduino has (as many others) have a CH340 USB to TTL converter in them, so you need to install an extra CH340 driver to let windows establish the connection.
The Can-Shields are almost the same. I work with a cheap one from keyestudio. It worked on the first attempt.
Connecting the BNO085 is really easy. You find a description on the Adafruit website.

Installing the .ino files on the Arduiuno

First download the files from Github: GitHub - MechanicTony/AOG_CAN_Uno_Nano: AgOpenGPS using Arduino Uno/Nano with CAN Shield

Download the MCP_Can Library: GitHub - coryjfowler/MCP_CAN_lib: MCP_CAN Library
Unzip all files.
Load all the .inos from tony because there are dependencies.
Embed the MCP_Can Library.
Upload the sketches to the Arduino.

Setting up the Ardusimple RTK2B and the NTRIP client is explained in details on the forum. As I am living in Bavaria, I can use the RTK Correction signal from Sapos Bayern. To connect to the NTRIP caster, I just make a wifi hotspot with my smartphone. In Windows 10 you can set a wifi network as metered connection to prevend it from downloading updates and high connection costs.

Connecting to the Valve Bus of the tractor:

On the right side under the seat there is a cabinet with the main Battery Switch, Diagnostic harnesses and ECUs. In the back of it you should find a lonely connector marked „X230“. It is a Deutsch-DT 3-Pin that looks like the one on the picture.

Deutsch Dt

Congratulations! Now connect the green wire to CAN-Low and the yellow one to CAN-High of your arduino shield. „Low = green like the grass, High = yellow like the sun“.

I used standard untwisted unshielded wire. Maybe DMX/Microphone cables from the stage/event equipment are better: twisted and very durable.

If all works fine, put it in a dust-proof enclosure and mount it in the cab. I do not recommend BNC Connectors for the antenna because they get loose after some time. Go for TNC or SMA instead.

The Terminal is mounted with the screwholes of the original AutoGuide C3000 Terminal. Tablet-PC is powered by the original 12V 3-Pin Front Connector in the right front of the Cab. The tractor kills the power after some time the engine is off so there is no need for a switch to protect the battery.
Basic settings

Most of the vehicle Dimensions are listed in the operator manual of the tractor.
Please do not forget to calibrate the backing up detection:

Steering settings

First, set the correct WAS counts per degree, the steering angle comes somehow not correct from the Can. I set it to 20. The interesting thing is that the tractor does not steer as wide as you can steer manually. This makes U-Turns often very difficult. Maybe someone knows more about it?
My current settings work well but may not be the end of science:

P = 50
Max = 249
Low = 50
Min = 0

aggressivity = 1,3
overshoot compensation = 1
integral = 20
PurePersuit works not as smooth as Stanley in my case.

For engage via button on the tractors joystick and disengage just set “Steer Enable” in the steering settings to “Button” and send + save.
If you have any questions or problems during your build do not hesistate to ask.
Suggestions for improvements are welcome! I am also looking forward to seeing your builds.

Best Regards,


Work Switch
Most tractors have an ISO 11786 interface.
Very similar to ISOBUS, this is a 7-Pin Amphenol C016 Plug. Pin 7 in the Middle is common ground and Pin 4 turns high (15V) when 3-point-linkage is in high position and low (1,5V) in low (work) position.

In order to get the signal to AgopenGPS without our PCB we need to feed the signal trough a Photocoupler. The Input needs a 680 Ohm resistor and the output connects to Pin D7 and GND of the arduino.
In the picture, I used the wrong colored cables. The Photocoupler is a PC817 located under the heat shrink

Wiring Diagram:


If you wanted to you can read the ISOBUS CAN message and get the IN / OUT of work and the hitch postion 0-100%.

ISOBUS_Rear_Hitch.ino (2.0 KB)


Hi Tony,
thanks for the Ino file. When you need the actual hitch position going via can is far easier than the 0-10V Signal of the analog Signal Port.

1 Like

Hello I just had a mf 7719s with isobus and pre equipped with autoguiding. I can’t find the x230 socket next to the seat. there change places on the s? thank you

On the 77 S models I have seen it is around those diagnostic connectors beside the seat. Sometimes it is behind covers / brackets hiding but around that area.

prise x230.pdf (472.7 KB)
I just received this document from my dealer. Can I connect to x184?

Yes, but both plugs should be within about 200mm of each other

Hello, I do my tests. Is it normal that there is no return with the arduino uno, I would like to point out that I am not connected to the tractor thank you

Check the serial monitor in Arduino program before connecting to AgOpen.

You can show a picture of the serial monitor if you are not sure.

A baud error - looks like a baud error, 9600-38400-57600-115200

Could it be a connection error between the uno and the can module? This is how I came out:

Entering Configuration Mode Successful!
Setting Baudrate Successful!
Starting to Set Mask!
Setting Mask Successful!
Starting to Set Filter!
Setting Filter Successfull!
Starting to Set Filter!
Setting Filter Successfull!
Starting to Set Mask!
Setting Mask Successful!
Starting to Set Filter!
Setting Filter Successfull!
Starting to Set Filter!
Setting Filter Successfull!
Starting to Set Filter!

What CAN module are you using? You might need to change the CS pin to 9. Near the top of the Arduino sketch you loaded onto it.

C est celle ci

Have a look near the top of the Arduino sketch you will see something like:

CS pin (10) and change to (9)

Then check serial monitor again after reprogramming


Je viens de faire des essais sur le tracteur. Au début j avais le retour du capteur d angle dans aog. Puis plus rien.
Voici l écran du moniteur série. Quel serai le problème

La bno n etait pas mis au moment de la photo