A few weeks ago, i installed an autosteer on a tractor using the PCB V2 of Brian. This works great and the PCB definitely made the installation easier. However, I found that the complexity of the setup is still too high and I think it can be made more simple. I saw the other PCB designs (like the KaupoiMOD PCB v3) which address this issue, but I’d like to push the reasoning even further.
The project would be a new PCB, designed to fit in an hardened enclosure, embedding all the electronics that are currently somewhere else (ZED-F9Ps, switch / hub, hydraulic lift relay, etc.). To make this new PCB as useful as possible, I’d like to know what are your requirements, you users of AOG. Thus, I made a poll to collect your opinions more easily :
You will also find there a more detailed description of the project. It should take no more than 5 minutes to answer the poll. If you have more detailed suggestions that can’t feet the poll, we can discuss on this thread.
Hi @Stabilo,
Thanks for the suggestions. I gave a look at the PCB of Andreas (this one : https://www.autosteer.cc/produkt/agopengps-set-baugruppe/). It’s a neat setup which groups the F9P together with all the other stuff, precicisely what I want to do. What I miss in this PCB is the rugged connector directly soldered on the PCB (like with the enclosure I suggested above).
TE has effectively a line of rugged connectors called Deutsch. In the same line, they have precisely rugged enclosures with DT or DTM connectors. Unfortunately, both designs are too small to fit everything. Cinch does almost the same thing but has one bigger enclosure size, which is why I chose them.
No need to stack PCBs, and they wouldn’t fit in the box anyway. I can fit a lot of SMD components on the bottom side (2.03 mm height max), which should give enough space on the top side for modules and through-hole components.
I just ran across your discussion with @buched about his PCB : Custom pcb. What I’m trying to do is very similar, only with more stuff on the board (hub/switch, power supplies, more relays, dual F9P…), hence the need for SMD components.
I use Andreas and V2 tiles. Andreas are easy to use and work brilliantly. V2 are smaller and when there is no space it is easier to fit them somewhere. On the Andreas board, I would improve the location of NANO and F9P, you would have to either move them inside the PCB to have a place for USB cables that can be led inside the box or alternatively move to the edge of the PCB so that you can connect USB cables directly through the hole in the box. The same is true for V2. It would be great if you moved the nano to the edge of the PCB, then a small hole for the plug is enough and you can connect the cable from the outside of the box without additional adapters.
I make handles for ordinary USB cables on a 3d printer, which I then screw to the housing, they work very well.
@baraki I saw the PCB of Andreas, and I think it includes a lot of good ideas. I didn’t see any V2 anywhere though, do you have a link ? About the plugs for cables on F9P and nano, if I go the way I want to, they won’t be a problem as all serial connections will be done using PCB traces. No more cables ! I’m curious about your little handles for USB cables though, do you have pictures ?
@Larsvest connectors for this enclosure are rated for 10 A (see the brochure https://belfuse.com/resources/brochures/cinchconnectivitysolutions/modice/br-ccs-ice-modice-and-shs-brochure.pdf). For extra security, it’s possible to connect the 12V and the GND with two pins for each, giving a max current of 20 amps.
I agree, it would be nice to be able to change important modules easily, using PLCC sockets or headers. If there is enough space available, I’ll do that. The SkyTraQ module looks promising, but I don’t know it so I’ll have to dig deeper (for example, how to build a base station using it ?) (EDIT thank you for having completed your message above)
It’s good to know. On the other hand, as indicated by Bel, their ModICE enclosures are designed for “extreme environmental conditions commonly found on commercial and off-road vehicles”. I guess we won’t find anything more solid and reliable than that. If the box stays in the cabin like most people do today, it should be fine. Did you have another reference in mind ?
Also think of a place for a single or 2 mosfet switch. It is useful for switching on auxiliary valves, and in standard relays the contacts burn out and noise occurs.
I see what you mean. It could be useful indeed.
Could this idea be extended to the section control, in place of relays ? Is there people who thought about that ? Are there sprayers or seeders or other tools that can’t work with MOSFET switchs for section control ?
It’s not easy with precision air seder. In the factory controller, switching off a section is a single button that subtracts or adds a section with another press. I don’t know if AOG could control these buttons ??
Disconnecting the motor of the section, the controller, not seeing the pulses from the encoder, displays an error and restoration of the power supply does not = start the engine.
I was thinking to simulate the encoder during AOG engine shutdown and thus cheat the factory driver. Maybe someone has a better idea?
Connecting the EHR switch is also not easy in my MF. Lowering, Raising, Neutral - Each of these switch positions gives a specific resistance pattern on the switch pins. A simple relay does not work.
All right everyone, as promised, here are the results of the poll I made a few weeks ago. I had 24 answers, which a nice sample I think. You can still answer though.
Based on your answers, and also on what I need from this design, here are the colclusions:
Most people think the idea of an all-in-one PCB enclosed in a rugged enclosure is a good idea. Phew!
Most people think it would be at least nice to reduce the amount of wires needed to setup the autosteer. By grouping functions on a single board, this issue would be at least partially addressed (there is not much to do about wires across the tractor though)
People are more divided about the digital connection means. I must admit that the question was not really clear, as it partially mixed considerations about connection and about processors. In conclusion, I thing I will focus on USB compatibility with an embedded USB hub. Ethernet is nice and has a lot of advantages (see here and here), but more complicated to implement and makes less sense on a one-board setup, in my opinion. Also, I can’t really keep both options available, I’m afraid it would be a nightmare to design.
Almost perfect split between people who want one or tho gnss antennas! I will do my best to make these two solutions available on this PCB, using the code from MTZ8302 on ESP32.
Most people think antennas should be removable, probably in a cost reduction approach. It doesn’t change much for the PCB, but good to know.
Most people don’t know what’s the best position for MMA and BNO. From a physics point of view though:
MMA can’t be impacted by metals. But it should be horizontal and maybe not too high to avoid being tossed from left to right in the field.
BNO is used as a magnetometer (or compass), so it makes a lot of sense to put it away from metallic surfaces and outside of metallic enclosures. Kaupoi tried this anyway and, against all odds, reported it worked fine. So at this point I don’t know nothing no more! All I can tell is that i already put it on the roof once, together with MMA, both connected through 3.3V I2C with a 3m long twisted pairs cable (details here). Works fine.
I’ll output I2C on the conenctor, probably use an I2C extender like P82B96, and anyone will put MMA and BNO wherever he wants if he chooses to build a single antenna setup.
Most people are not afraid by SMD components. It doesn’t mean they will solder them by themselves though. I’ll do what I can to source components from the JLCPCB parts library, but their catalog is not that thick so it may not be entirely possible. It was also reported that they had issues with their stock inventory. Other PCB manufacturers / assemblers can work with components you send them (like PCBWay), but the price will be higher (I didn’t do the math though).
As said above, I will embed a USB hub on the PCB, which should satisfy a lot of people. Sorry for Ethernet enthusiasts though…
I will output a 5V to recharge a phone, and also an adjustable DC power supply for a tablet. I personally find these useful, and a lot of people believe the same.
Most people think the relays for sections control should be outside of the box. I didn’t expect that! But that’s understandable, as you probably are looking for modularity here. It would be a shame to have to carry a bunch of unused wired for section control when ploughing or mowing. But what if I told you that it’s possible to have 8 relays on a separate 18 pins connector, but on the same ECU box ? Damn, I don’t know about you, but that looks awesome to me! Also I’m pretty sure i can fit them inside the enclosure. I will also output USB on the other connector for people who want their own separate box, with more than 8 relays for example.
Hydraulic lift control shouldn’t be an issue. I may use a solid state relay or MOSFETs though, for their longevity, as discussed just above with baraki.
