Anyone using AOG to steer the tractor with a grain bagger?


I am wondering if anyone tried to steer the tractor with a grain bagger attached. The speed would be like 0.1m /s or even less. If so what were the results? With RTK or without?

Or would be the steer menu be enough when the wheel angle sensor is trying to keep the wheels straight. Most grain bagger tractors do not have the tightest steering anymore these days… :slight_smile:



This is an awesome idea, but I think you would need a way to ignore speed all together you would be so incredibly slow.

I simply remove the low speed condition in the arduino code, so it’s always steering, even when stopped

Works pretty well for my trench digger (0.05 - 0.2km/h) but it can take a while to get straight on the line

could you explain how to remove the low speed condition? i have to plant vegetables at less than 0.5kmh, now this is the limit.

Line 530 in the USB code:

if ((bitRead(guidanceStatus,0) == 0) || (gpsSpeed < 0.1) || (steerSwitch == 1) ) { watchdogTimer = WATCHDOG_FORCE_VALUE; //turn off steering motor }

Changes to

if ((bitRead(guidanceStatus,0) == 0) || (steerSwitch == 1) ) { watchdogTimer = WATCHDOG_FORCE_VALUE; //turn off steering motor }

I.e. Just removing the piece that checks for speed when deciding whether to turn off autosteer

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Hi Charles,

Are you using RTK correction?

Regards ,


Hi Johannes,
yes I am using RTK

Thank you!

That would be my challenge, so far we got away with a Novatel antenna and Glide enabled. That prevents the lines to move a lot during the day. For super slow speeds RTK would be a must I think.

I’ll start out without gps signal, just keep the wheel angle sensor at 0. If that won’t do it I’ll have to add RTK.



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RTK is cheap compared to overlap. Smaller the implement, quicker the payback.

Without the RTK and using a poor GPS, best bet is to slow down the GPS input.

I made a filter that did two things:
It would average several fixes, and it would ignore several fixes.

So every 2 seconds it was getting an average of the new locations. Worked pretty good at very low speeds.

Hi KentSuff,

Would you be willing to share the filter?



Is it the filter inside tree planning mod?

It was, but it blocks the latest updates. I have not figured a way to add it back yet, so I have deleted it.

I’ll try 5.2 for now and see how it goes. I’d have to setup a base in the field and and use radio to transmit RTK. No cell phone service in the field. Omnistar would be an alternative. I’ll report back.

@kentstuff, do you have an older AOG version that still works?

You build a small step version for 4.3. Is it that easy to have the same effect with 5.2 like Cquick said? Just removin the piece in the ardoinuo code, and you can plant veggy as slow as you want? :wink:

Almost, It is not in the arduino code but the main code. But by some minor mods, and checking the GPS less often, you can plant veggies as slow as you want. With the current set up, the screen can get jumpy when you get less than 0.5 km/sec. What really needs to happen, is a blending of the simulator and the gps signal. Keep updating the current position on the screen based on the last updated GPS. When you get the new GPS fix what you missed. When you are going super slow, how far off the signal can you be in 1 or 2 secs?

Edit: What @CQuick said is in the Arduino code. So technically both codes will need a bit of tweaking.

3 to 6cm if I plant very quick at 0,4km/h it will be 11cm.
I think I´ve to try first with 5.2. With 4.3 the signal was not updated below 0.5 km/h. So it was not jumpy, it was random direction.
If I got you right, the plan could be less positions from GPS to get a bigger distance between the positions, what helps the software to find al line. correct?

I will test it with the 5.2 and arduino code mod tomorrow and see what happens. Raining all day here, so time for playing with GPS

0.5 fix2fix should be enough to plant veggies at 0.2/0.3 kmh, it hink the cquick tweak does the job


I’ll try to put together another small set version next week.

Well next week started early. Here is a copy to play with. I added it onto the MicrOpenGPS. It allows for a smaller minimum speed and you can turn it off and on. It should remember your settings unless starting a full new program.

With inspiration from @Vili this is the new splash screen:

Here is the link.

Also modified the Arduino code per @CQuick except I set it to gpsSpeed < 0.01:

Filter and small step is here: Turtle border green, filter is running.

Keep in mind this is the micro edition and it only has seven sections. The eight was converted to the geofence.

Zoom In Level has also been increased due to it being micro. The turns can me much sharper as well.

Also, run it in VTG and it will follow the heading much better at slow speeds than Fix.

Give it a try, if it doesn’t work just delete it and go back to 5.2. It works very well straight out of the box.


I’ll play with this on the weekend. Thank you!