I thought that I had clear picture about this but I’m getting confused now.
I put a list on things that I think that I need to order:
1 x Relay board, 8 channel? Or is 4 channel really enough?
1 x on off switch to cut off power from relays
4 x on off on switches for sections to manually use them
2 x on off on switch for pressure control and main valve
1 x arduino nano
1 x LM2596
1 x 5 fuse box to protect valves
4 relay board is enough but better take 8 so if relay fails you can change section to working one. More importantly you may find AOG section control 0 tolerance for border over spray annoying that it shuts down entire section for 1cm over the border spray, so you have option to upgrade sprayer to 6 sections, to have last nozzles from either side be separate sections so it only shuts down one nozzle when you are little bit over field border.
You need to have 4PDT switch to cut power to relays as @Larsvest suggested to prevent backfeed and prevent possibility to have both motor directions accidentally powered if you forget to turn off manual switches.
There are Arduino codes and circuits on GitHub.
These circuits provide stand alone functionality and section control by AgOpenGPS. I’m using this for 5 years now.
There is feedback to AgOpenGPS in Auto and manual mode.
So simply take this.
You can realise it on a simple home made pcb or buy one. (Prototypes available)
I now studied the original control box with voltage meter and there is only 2 wires per motor. So when you click the switch ground and 12v switch places. Doesn’t this make it so that it is not possible to use this configuration with only 4 relays?
I really like the secion control you build. I’ve been reading your github but i do have a question before I might build one myself too.
I have a V4 micro PCB and use a UDP network in my tractor for all the different PCB’s, I know you have a version with the ESP32 with Wifi but is there also a possibility to use an ethernet cable? for example with a nano and an ethernet shield connected to it? Or will there not be enough pins to connect the sectioncontrol and the ethernet to?
the number of pins needed depends on your sprayer: how many sections, rate control (manual, by +/- motor, via flowmeter), maybe boom control.
The ESP32 code supports Ethernet (not tested with actual libs) with a W5500 chip. I use this version:
If you have some more time, some guys from the developer group are about to draw a PCB. I made one for vineyard purpose (2 sections, 2 fluids, 2 pressure controls manual +/-). Feel free to build a PCB by yourself. I also did this with a prototyping board Arduino UNO format, that I put on top of an ESP32 in UNO shape.
WiFi works good, if you have a direct access to the PCs Ethernet port. Routers cause delay. My setup is like this at the moment: PC - ESP32 w5500 - WiFi (same ESP32) - section control. See:
I’ve built a couple of versions of the hardi control box. The motors are just 2 wire and I use a dpdt relay to switch the signal between high and low on each wire. For the master on-off when using agopengps i use diodes on each section connected to the master relay so once any section is on master will be turned on and when last section is off master is turned off. Some hardi sprayers don’t have master on/off only section control.
Good evening, thank you.
I started with the GPS autosteer, I got that working and the “normal” section control is finished too. So i’m looking for my next step up.
our sprayer is 7 sections with a +/- motor, I’ve already made a seperate boom control, but that could be integrated into one PCB.
I’m curious about the PCB thats being developed, altho it might be a cool thing to do myself too, and to learn something about designing a PCB. the section control you showed in your YT video’s was that still a breadboard kinds setup? no PCB made for that?