Planter steering with AoG

I’m considering trying to steer a planter with AoG. The tractor has an RTK Autofarm, it’s driving nicely but the planter doesn’t pull straight or consistent. Any recommendations for setting up AoG?

We don’t need a large amount of corection (only a few inches). We want to pivot the main load bearing axle (rear fold kinze planter) without a WAS (just use a voltage divider at 2.5V). Could that work with dual GPS on the axle so that AoG thinks the “tractor” is pointing in the direction as it’s steering without a real WAS and use Stanley?

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Reconsidering, we think swinging the drawbar should do enough, and one gps antenna should also be enough but how to skip using a WAS?

Wouldn’t it work with true PID-control? If the WAS was fixed at 2.5 V, the I-term would make the implement “steer” until the implement antenna is at the AB-line?

My understanding is that the current version of AOG does not include the I-component but perhaps an older one does, like 3.09?

Maybe just make PID control for “Distance from Guidance line” instead “Required steer angle”?

I’d like to avoid modifying AoG or the Arduino sketch of possible so that I can use the latest versions.

I’m trying to think of what it looks like from a normal AoG perspective. With the autosteer turned off, you’d be driving parallel to the line with an offset. Engage autosteer and AoG will request a wheel angle bto intersect the AB. The Arduino will continue to output PWM to turn the wheels because the WAS always says it’s pointed straight forward and it’ll never reach the target wheel angle but as soon as the Arduino outputs PWM, the draw bar shifts sideways and the planter will start to move closer to the line. This will cause AoG to request less steer angle and the Arduino to output less PWM. Once the planter reaches the AB PWM output should stop.

I expect there will be some over shooting if I have too fast of a reaction but maybe the dual low/min PWM can help with that, fast movement when far (>4") from the line.

So I’ve been using AoG 4.3.10 to steer our planter using the planter tractor’s swinging drawbar. We used a hydraulic cylinder to control the drawbar, using one of the JD 8320T’s own hyd valves/remotes/spools. JD runs their valves at 100 hz so I set the Arduino to use ~120 hz. JD’s controller monitors both wires (pulsed 12V & ground) running to each coil (4 wires in total for one valve) so I have to isolate them from AoG’s pwm controller, I chose to use a 4 SPDT relay board. As long as I don’t try to manually control the valve with the tractor’s switch while AoG is controlling it, then the tractor is none the wiser. I have no WAS, instead I modified the Arduino sketch to always report 0 deg wheel angle. I’m using a single F9P in the cab (antenna mounted on the planter almost perfectly inline with the seed boxes) which receives RTK correction through AoG/usb. It works surprisingly well considering I’m still only using my initial guesstimated values for “tractor” dimensions and gain/pwm settings.

I agree with @NorthernFarmer & @d1ken. Distance from guidance line is what’s really important, could also use a WAS for feedback with an I-term. The planter reacts quite quickly (short hitch, 24 rows all “steering”). I came across a situation where I was questioning whether my setup was working correctly, AoG was moving the drawbar all the way to the one side but our RTK Autofarm steering in the tractor seemed to be fine so I didn’t know which system to trust. Later my dad had time to measure some pass to pass spacings and turns out AoG was working better then the ol’ AutoFarm. I now believe there’s been more error in our tractor’s steering than the planter wandering. The next day I didn’t notice any strange happenings, the drawbar stayed quick close to center all day.

I’ve been leaving AoG steering engage even while turning around at the ends, it’s not ideal in that AoG swings the drawbar back and forth a couple times. Ideally I’d like it to swing to the one side (to help the planter get on track quicker) once I’m about halfway through the turn and then center again as needed once the tractor has straightened out. I’ll try to get a good video to share, hoping to setup a camera to capture the drawbar swinging & AoG at the same time.


That’s great! I’d like to see a video of it working!

This is a very niceway to steer an implement using with almost original aog setup! Maybe there is such a way to steer a plough too!
I wil try your setup to plant potatoes next year too! This year with only tractor autosteer, planter likes to pull the tractor off line quite a bit sometimes.

AoG 4.3.10, USB Nano with modified INO, F9P @ 8 hz with RTK via AoG ntrip. Everything is in the tractor except the F9P antenna is on the planter slightly ahead of the seed exit (had to build a coax extension). I’m controlling the JD 8320T’s own remote hydraulic PWM spool/valve @ 120-ish hz with a L298N dual H-bridge driver (outputs connected in parallel, only switch +12V) to swing the tractor’s drawbar ±10". I’m using 4 SPDT relays to select JD or AoG control of the valve, as long as I don’t touch the JD control lever while AoG is steering the tractor doesn’t complain.

Most of AoG’s tractor & implement settings are default except I have set the GPS antenna position as if it’s on the rear axle and the implement as a rigid trailing only a few inches behind the rear axle inline with the seed exit. AoG is only steering the drawbar, not controlling any sections but I setup it up as 12 sections anyways (24r30 planter) and the tractor has its own Autofarm RTK steering.

I leave autosteer engaged while turning around and it works but as you can see in the video is looks like it takes AoG a few seconds after the planter changes direction to control it in the correct direction. I expected it would try to steer the planter “wider” then it normally would follow the tractor which would be desirable for getting it on track quicker.

You can see the video isn’t the smoothest, the tablet has trouble streaming a 2k IP camera (sub stream didn’t work for some reason) and screen recording all at the same time (using OBS). I suspect there is some thermal throttling going on. I also was not able to eliminate all of VLC’s input buffer delay so the cylinder response is better then it appears.



Where does the planter fault position come from (the land seems flat and the tractor drives on a abline)? How big does the fault distance get, if AOG autosteer is off?

I think the fault comes from changes in soil and resistance from the rows. According to how far AoG swings the hitch, the error looks like ±5". We’ll know how much better or worse this was when nudging the combine during corn harvest.

Definitely something I would like to do with two AOG systems. I wish there was a way to sync the active AB line or AB curve between two AOG programs, so that I wouldn’t have to select the line in both systems every time I change the line.

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At minimum, maybe using something like Dropbox you can sync the AB lines between systems. That being said, can you run two instances of v5 on one system with both saving/loading from the same folder?