John Deere AOG Project (6630, Hydraulic valve)

Thought I would write up a project on here to share my little project that I have been working on.

Have used Farmer GPS for many years on a tablet in my 6630 tractor, connected with serial to a SF3000 John Deere GPS receiver. No activations, just basic SF1 signal.

After changing our combine last season, and it already having autotrac on it, it changed my life forever, and not having it in the tractor was simply not an option any more!

But have always known that if I was going to get it on the tractor, I wanted RTK accuracy so i could go back to the same point year after year, or else I couldn’t really justify int he investment. But after looking into the cost of doing that, using OEM parts, and the biggest killer, activations…welll…thats where AOG comes in!

So started out just using AOG on the tablet in place of FarmerGPS, still driving the tractor myself, to get used to the software, then started my project of autosteer!

Due to awful weather, and tractor in constant use in the yard, The first thing I actually did was build the RTK base station, which I wouldn’t be using for some time, but just wanted it done / running and sorted, I already made a thread for that, which can be found here:

And a picture of it installed:


Ordered up the components, and PCB and set about building the PCB:



Connecting via UDP as want to use UDP for all elements of this system, I think its a nicer way to connect everything, and already have ethernet switch / network in the tractor, as well as a long range wifi link which keeps my online on 98% of my farm, and 4g failover from mobile teather if it fails.

Put it in an enclosure, used some Weipeu connectors, as recommended by @BrianTee_Admin (Thanks Brian there great!), to make it easy to remove if needed. Also some relays etc for various things, fuses etc also buried in there.



Also made a control panel for in the cab, main power (turns on PCB, and gives power to everything in the system via main relays. Also has two safety lock switches, one kills power to cytron , the other kills power to a hydraulic shutoff valve before my steering T’s to isolate system totally for on the road. As well as a work switch to map when implement isnt connected itself, and also the main autosteer button (momentary)



Made a bracket and mounted it in the cab:





Next up was wheel angle sensor, decided to use the landrover suspension sensor, mainly because it was easy to get hold of here (UK) and cheap / easy to replace in event of a failure, and thought if it was designed to be in muddy wheelarch, it should be fairly well protected…

Built a bracket first to mount it:


Painted it up and fitted to the tractor, also upgraded the plastic linkages to rose joints, mainly to give me fine adjustment, so i could set straight ahead at precisely 2.5v, and also as stronger / should last longer with zero slop.



Just picks up a factory bolt hole on the axle, and then clamps around the entire axle, super solid / didn’t want to weld / modify the axle at all.

Then for the hydraulic setup, ordered up the valves and fittings, Corona virus in full swing now, so having to order everything online, including the hoses, which found a cracking website for custom length hoses, with endless choice of fittings, and actually cheaper than my local hydro outlet!




Made up a bracket to mount everything on:




And got it mounted under the cab:



The tractor is a load compensated system, but fixed displacement (gear) pump, so basically works like a full CCLS, with LS line that brings tractor up from standby pressure to main pressure when pressure is applied to the LS line.

I T’ed the stock orbital output lines, and pulled my Pressure (P) tank / return (T) and Load Sense (LS) lines from the powerbeyond system on the back of the tractor, firstly because I didnt want to interfere with the stock orbital system for safety, and also because theres no bleed on the stock orbital LS line, so would require a orifice or else system pressure would stay up.

I have a power beyond block already on the tractor as it has a front loader, for which the valve block is mounted in the same place under the cab, So to save long pipe runs, I was able to T the P / T lines right there next to the block, and also the LS line, with a shuttle valve fitted so either valve can call for oil without back feeding each other.


Got it all wired up at this point and ready for first test, Eventual plan is to run dual F9P’s with @MTZ8302 's ESP dual antenna code, and so I can take advantage of RTK with the base station I made. But initially to prove the system, I will be using the existing SF3000 unit thats already connected via serial to the tablet.

Got it out field for its first test a few days ago:


This was planting veg at 0.4kph, holds the line just fine, however, I am still trying to get the valve control really sorted. It works well enough, but you can feel it jerk a bit in the cab as it makes corrections.

I am finding the valve varys alot at which point is starts to move, based on coil temp etc, which makes it tricky to setup so its always smooth, as the min PWM point (where its smooth) can move 5-6 pwm in a matter of minutes… I think a smaller valve would likely hide alot of the problems, but I cant seem to find anything suitable (load sensing 5 port proptional valve) other than this (Hydraforce SP10-57C…) Hydraforce also make a SP08 series, which is smaller and much more suitable flow, but only make it in a 58D model, which leaves steering lines open to tank in neutral, which isnt much good!

I am looking into introducing current monitoring on the valve wires, and a PID loop to use closed loop current control on the valve, as current is directly related to movement , unlike PWM which is effected by many things in the coil…ongoing project so will see where this goes, also possibly looking at using an external 12/16bit i2c DAC, to give me some more resolution on the output to aid smooth control…

If anyone has any input on any of these matters id love to here…as said, its working either way, and I guess i should just be happy, but im confident it could be alot better, so will be an interesting project!

So much thanks to @BrianTee_Admin for all his work, and also all his help on here / telegram group, and also all the other members I have been talking to / in discussion with regarding the hydro valve etc…so great to have a community like this, such a cracking project.

Cant wait to get out in the field and do some more fine tuning etc!

Hope it was an interseting read for some!


Very nice description and setup . Do you have a valve that can reduce pressure or flow. It sounds like you have full pressure when steering, when you say you feel jerks in the cab.

I have a pressure compensated flow regulator in line of the P line, but not found it really helps other than just slowing down max flow, but when valve is partially open / making small movements, its never really going to help. Valve is really to big but cant find anything more suitable for LS systems…

I think once I get the control dialed in it will be better.

Update to this project,

Got my dual antenna project finished up / fitted to the tractor, started some initial testing in the yard, but sadly super wet again at the moment so yet to get out field and really try it out.

Bought pair of F9P’s and an esp32 (ESPDuino), wired across the UART ports with bridge wires to allow me to stack the boards, and also with the power / ref voltage pins and mounted it in a box, which is mounted in the roof of the trator:

IMG_20200501_154711 IMG_20200501_171500

Then made up some mounts for the antennas, wanted to get them as far apart as possible and up high enough that my existing beacons / antennas etc wouldnt be in the way of them, so mounted them up to the side and above the flashing beacons, and stiffened up the mounts so there was no movement / vibration in them:

IMG_20200429_153421 IMG_20200429_161427 IMG_20200429_161445

A little hard to see, but the black parts next to the orange flashers!

Will update with my results in the field! But both units are getting full RTK fix from my base station in the yard, and giving a RTK fixed location into AOG, so looking promising, connecting over UDP (Wifi) at the moment until Ethernet support is added.


Add pressure compensator to the solenoid valve and all problems with the settings will disappear. In my experience, adding compensation completely changes the operation of the solenoids and allows smooth control. It is also easy to calibrate the PWM settings because the system is sensitive to any errors.
Remember that the amount of oil that flows through the valve depends not only on its opening but also on the pressure difference at its ports! By stabilizing this difference you will get a better effect than with PID control.

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Do you have an example of said pressure compensator?

Something like this? Load sensing OC steering - #42 by Pat

link of pdf

Interesting, exactly how does it get plumbed up? Assuming needs to connect to P, T, and both output lines? Anyone have any photos of it installed ?

Here are the valves I wrote about mounted in my Puma 225 (LS) and MF 5455 (OC)
I installed such sets also in NH T5 and case MX both with OC system.

Are these load sensing OC systems with an LS line still?

Could you list the exact valves your running?

I can’t really see it on your pictures… Does it work like this?

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LS is connected via check valves (blue arrows) directly from the actuator line - ports A B.

Would it be possible to draw a diagram of the entire hydraulic setup?

So you use a 4/3 proportional valve… but I don’t see/understand what the compensation valve actually does inside that block…
Do you know wich lines it is connected to? Is it in between the Pump and the proportional valve and gets “signal” from A and B?

The compensation valve consists of a slider on which, on one hand, pressure from ports A B connected in one line by means of check valves and, on the other hand, pressure from the line between the compensation and proportional valves. In addition, the spring sets the pressure difference. For example, if the input is 160 bar and AB ports 1 bar and the compensation valve is spring-loaded at 8 bar, then there will be 9 bar at the input to the proportional valve.
If there are 100 bars on ports AB and 160 on the input P then 108 bars on the proportional P input.
If the pump is currently supplying 50 bar and the ports A or B have 10 bar, then the proportional input will have 18 bar due to the compensation valve. e.t.c
If anyone needs these valves from ATOS, I can help, I have a good system with them.

I would also like to try a system with 2 antennas but for now I have no idea how to go about it, especially how to connect it to AG.

Update to this project…

I have been trying to get my dual antenna setup up and running, but having alot of problems…

Have spent the last few days fighting a signal loss issue, which turned out to be a USB hub, so note to self / anyone else having similer issues, even with nothing plugged in, by simply having this USB hub plugged into the computer, It was causing all kinds of chaos with my GPS signal!

With that resolved, I went back to a single F9P, no RTK, clean install of AOG, and started bare basics, single USB GPS (F9P), fix to fix 4M, and finally had a fairly stable gps signal / things looking much better. So slowly started adding things again one part at a time, to make sure nothing started a problem.

Long story short, have now got the system up and running again, with UDP connected autosteer board (only option anyway now due to having to use wifi, because cant use the USB hub for any more usb devices!), got my valve set back up, setup NTRIP, F9P gets RTK fix now at 8hz as it should, and the tractor follows the line well, Im finding I have to use higher gain at high speed, and much less gain (9/10 at low speed, 100+ at high speed) but if i make this adjustment, it works very well indeed!

So overall, things are working great, heading is set to 4M fix to fix, which works fairly well, but can still get a bit erratic, and I am sure with working dual antenna, it would be so much more stable.

Moving onto current problems:

1 - Still cant get dual antenna to work, it does “work” but seems to “lag” AOG, steering is slow to respond, and whenever I use this setup, I just get a slow curvy line, constantly steering left, then right, over and over…It seems to me, that when using this, everything slows down…GPS feels laggy, direction change feels slow on screen, position is correct, and heading is correct, so it is “working” but it just feels laggy, andI think this is why its not steering as its to late to respond so AOG just steers to late, and can never get straight… But both F9P’s are set at 8hz, and the ESP is set at Matt / Franz’s recommendations, so im at lost end with that at the moment… Have ordered another ESP32 as wondering if maybe its at fault? Anyone got any thoughts?

2 - Second issue, which I’m hoping maybe someone else can help with, Obviously because I have set the tractor up for Dual antenna, I have antennas to each side (89cm offset to right)…So have to setup the tractor antenna offset in AOG to 89cm. Now the antenna is right of center 89cm, so I should have to enter (as Brian confirmed for me earlier) 89cm… (+), but for some reason I have to enter -89cm for it to be correct, if I use +89cm, when I turn on the end, I am off the line by the offset / double offset…It was confusing me so much, I had to shield an antenna to be 100% sure I hadn’t cocked up / had my antenna cables the wrong way round! But can confirm they are not…
Is anyone else running an offset antenna on here, and if so, are they seeing the same problem?

I have an antenna mounted about 50cm on the right (I have a roof window and in the middle there was no way to hook it) and I use -50 to make it right.