Mueller SprayControl section control

Making automatic section control with AOG for old Mueller Elektronik Spray Control - S connected with Switch-Box for controlling 4 sections:


The electronic could be set at different type of valves (with or without bypass - mine are without bypass). The control signals (12V logic) are going to the SwitchBox to turn on relays for controlling flow and also to have feedback from different switches (manual/auto, rate +/-, on/off, section switches).

This is what is looks like inside the SwitchBox:

Upper connector - connected to SprayControl
Lower connector - cable output to the sprayer

Based on the manual, I made small PCB really quick and put DPDT relays on it. I tested the PCB as a static and it works well. The problem is with through holes for relays (too small), bad pinout on voltage regulator (has to be mounted upside down), and forgot to add flyback diodes on relay coil (putted manually) - it was my first PCB, so dont judge.


I have a pinout describtion from Mueller:
Lower connector - cable going to the sprayer:
Upper connector - connected to SprayControl



i"m about to make the same section control for this Mueller device. Did you just solder wires
to the switches and actived them with the relays ?


you may look here: Section control for the central unit


Any chance that you can re-upload the images that are not available anymore?
I would like to set up automatic section control for my mueller spraycontrol box and keep the existing box and switches and be able to use it in “manual” mode without AOG.

Has anyone integrated AOG section control with this box? How have you integrated?

An interesting way to do it would be to use a dedicated box which connect between the 2 mueller boxes (the top one that manages rate control, width, flow, … and the bottom one with switches) and before the sprayer. I think it would do the magic without making any change on the mueller boxes. Something similar to the teejet section control box:

Also I found this pinout for the mueller spray control box:

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I’m looking for exactly the same system as you showed (the teejet boom control). I want to keep the muller box original for my fellow farmer whom I share the sprayer with . a plug and play system between the original cabinet would be a solution. did you get any further with this project?

a relay board on poe with two plugs and a udp output seems enough.

I’m still working on it. The plan is to create a box that goes between sprayer and mueller, in this box there will be the controller connected to AOG (could be USB, UDP, WiFi, …) and relays. Section signal will be read from mueller and output section signal will be coming from a relay board. Controller will read section status from mueller box and it will manage the relay according to AOG (Manual/Auto). So no new switch needed except for switching Auto/Manual.
Note also that from this box there will be a cable going to another small box which fits between the 2 mueller box. The reason is that section signal must be sent to the top mueller box (spray control) so that it can calculate the rate. It needs to know the section status from the relay (when spraying in Auto mode).

So with this setup, you can just unplug the 2 boxes and switch back to original mueller system!

I ordered a lot of components (optocoupler board, ESP32, relay board, connectors harting to connect between mueller boxes, din 41622 connectors to connect between mueller and sprayer, wires, …) and last ones should be delivered…today ! So I expect moving forward on this in the coming weeks. Hopefully I can spray using AOG this spring :slight_smile:


So, here is the status right now.
The section signal is read using a PC817 optocoupler board and ESP32 is running my MTZ forked code which connect to my mobile hotspot and does UDP with AOG v.5.7.2
I’m using a 16relay board because I need 2 relay for each section (reverse polarity) and there are 7 sections. I will add another additional PC817 board after the relay in order to send GND signal to the rate computer when sections are open.

I have also 3D printed a box that will fits between the müller boxes and which contains leds for real section status (relay output) and the man/auto switch. This boxes will just forward signal between müller boxes except section signals that will be coming from relays status.