AgOpen pwm output and existing bang bang hydraulic valve

I have finally found some time to get at this, long time in coming. I have everything order and should arrive in next day or two, but have a couple questions regarding some existing hardware.

  1. I have a case tractor that I bought used and it had an old gps system, not sure what the name was it was gone when I bought it but it still has the hydraulic valve on it one of the on off valves not a proportional valve. Will the output from the cytron motor driver work with this type of valve or do I need a propotional hydraulic valve to make it work?


  1. I have a case 4420 sprayer that has trimble auto steer with the proportional hydraulic valve, has anyone disconnected the control between the navii controller and the valve and ran the propotional valve with AOG. For a couple of reason I think I would like to try it unless there is a reason not to do this.

3.I have an old ezguide 500 steer motor screen blew up so I have it sitting here, is there any reason that this motor will not work as a drive motor for AOG instead of purchasing another one?

  1. Is this valve going to the steering cylinders or is this plumbed in to control a rear remote? If you are hoping to control a rear remote, this can be done with a set of relays.

  2. haven’t done this myself, don’t know.

  3. I don’t see any reason why the EZ steer motor wouldn’t work. I think it’s just a DC motor in which case you would just isolate the + and - leads and plug them into the Cytron motor controller.

You might want to search for Charles Quick in the combine forum (CQuick) he set up steering on his Massey with bang bang and AOG as well as a bunch more here.

yes the valve is connected to the steering cylinder lines. Thanks will check out cquick

looked at CQuick’s posts and I see the info, thanks, but he mentioned moving the arduino output to 0 or 100 given that it is an on off valve, have provisions be made to do this in the software, I havnt seen it or do I simply change the arduino code to do this? Thanks

Yes bang bang works, you should probably set min pwm a little higher than to normal pwm valves.
Looks like your system has an adjustment valve (on the line below your bang bang valve) I believe it is used to adjust how fast your wheels should turn. Try 12 V on one solenoid and see how fast wheels turn :slight_smile: at full voltage. Actually the bang bang starts opening before 12V but not as nicely as a pwm valve.

1 Like

thanks will give it a try as soon as my equipment arrives

I use a trimble ezsteer motor. It works good plus you don’t have to have the 12-24v converter with it. But ezsteer motor did not work with trimble screen after, so must of fried something

Since its either on or off, wouldn’t you want to set your min pwm to 0? It’s a whole new world with bang bang valve. IT’s going to take some serious fiddling with most likely the arduino code as well

You could be right, I used coffeetrac button ino and bang bang 7 months ago, according to picture of my settings back then, it was with min pwm at 3, prop gain 4, output gain 12, and min integral 20. No change to ino other than normal selections in setup zone. I used IBT2 and wiring from old wiki. My bang bang began opening at 8 V , so it is not that different from pwm, it just doesn´t have the V shape opening in the spool, like the pwm have to allow a little oil to pass at the beginning of spool movement. I ended up with Closed center bang bang, because open center did nothing before full 12 V (Had to do work around as my system is open center) I now got cheap second hand pwm valve( still closed center), so can´t check if it was the final settings for bang bang i pictured.Today i would use Cytron, but the old wiki leads to IBT2 when going hydraulic.

So given the modifications to code recently would the coffeetrac ino still be the best one to try with the bang bang valve in your opinion

You mentioned that you have ordered things (pcbv2 and components, i guess) and I just looked at the latest autosteerpcbv2. ino and as far as I can see, it has all the necessary settings, so just use that.

Good thanks, half the parts arrived yesterday hopefully the rest will arrive by monday and then hopefully get this put together and give it a go.

1 Like

You have any luck? I have two outback valves that are similar to this

just waiting for the weather to warm up a touch, I have everything ready to go just need to install and try

There is no reason it shouldn’t, you just may have to be realistic on how quickly the wheels will steer and yet hold the line reasonably well.

I’ve wondered if you could also have a flow control to it, select 2 flows, a low when close to the line, a high when farther away

Did you figure out the wiring for the EN 175301-803 connector (2-poles and a ground) to the MD13S?

I havnt looked real close at those yet was going to look once I had it in the tractor, also mulling the idea of changing it for a pwm block.

Wouldn’t it be possible to play with the period of opening? As I read, a direct action valve should open in around 10 milliseconds. In an 8 Hz control cycle (125 ms) there seems to be space. (ie 30 ms open when deviation is small, 100 ms open when further from line) Just some thoughts from a newby…

Your Bang Bang valve will work quite well because you have the adjustment valve right after the valve block. I suppose it will let some oil pass direct to tank, and thereby reduce available pressure to move steering cylinder.
When Bang Bang valve is fed with more and more voltage from motor controller, it also opens little by little, except it doesn´t start letting oil pass before 6V or maybe 8V. Full bang bang is only when fed with 12 V and then 12 V the other way.
You have 2 connectors on the valve, one for each spool. In connector you could pick pin 1 for power out from motor controller, and pin 2 for GND of motor controller. And on the other spool pin 1 from the other power out from motor controller and again pin 2 for GND. So one cable with 3 leads from motor controller is enough. (You could experiment with which pin should have + for best magnetic force)

What about the coils with three connectors, a and b on one with the ground and then reverse a and b on the other?