Integrated ethernet on pcb

We were discussing the other day about a pcb for autosteer and a pcb for dual(single) GPS, that will stack together. Autosteer would have an ethernet switch pcb mounted to the board as part of the pcb. Header connections directly to spi pins of nano, and to header pins for the GPS pcb. Also an extra 5v regulator for power to gps and ethernet switch, etc. Plus a regulator 19v, for tablet power.
This would make for a compact assembly that has one 12v power coming in, and only one ethernet cable. USB would still be usable, but would create much more room for a USB hub.
Right now I have a fairly large box, and am nearly completely full due to wires and cables running everywhere. This would eliminate 2 short ethernet cables, one power cable to esp32, one power cable to ethernet switch along with the bulk of the switch, plus the concern of the ethernet cable working the ethernet shield loose under the nano.
Also this would allow us the use the small esp32 module, which could leave room on the GPS board for rtk radio or wifi module, etc.


I was wanting to leave everything as modular as possible, pretty much just the way it is, except to get free of some of the wires.
This module is 44.5 x 44.5 mm, and could probably have headers to make it plug and play. I don’t know enough about electronics to know what’s out there, that may be a better choice. I think it would need wifi, for the tablets that don’t have USB or ethernet connections.
I also don’t have software or experience with pcb design. However I believe. Either Brian’s pcb v2, or Kaupoi’s v3, world be perfect with another layer and some added length. The GPS pcb would just need to match.
This would make for a simple design, that anyone can solder and assemble. Matthias code works with ethernet, and can be used with one or two f9p’s. I believe it would make a more universal setup that would work for everyone, without the trouble shooting that comes from connecting wrong, or bad cables, and so on. Just solder it up, plug in the modules, and program.
If someone is willing to draw the design, I would be willing to buy all the components and do the testing.
Let me know what you think


Could use a set of jumpers that connect the SPI pins of one f9p to the SPI pins from esp32 to the header terminal. If someone wanted to use one f9p only, without a esp32, he could close the jumpers to have that f9p connected directly to the ethernet switch.

Kaupoi pcb v3 could be modified to bring mosi, miso, sck, ss, and ground to an extended place on the pcb, where ethernet switch could be mounted. Might be easier just to send 12 volt from the other end with a jumper wire.
LM2576 regulator
A simple lm2576 circuit could be built in to set to the right of the ethernet switch. It would provide 5v output to switch, and pin header to power both f9p’s and esp32. SPI pins from GPS board come up on same header strip to switch.
The header on the other end of the board would only need to be for mounting of the boards together. Also need a place to put an rj45 connector connected to port 1 of the switch. It could be on the end of the board on the bottom left side with the connection facing the other side of the board, so it wouldn’t interfere with the box if someone wanted to use a rail mounted box.
Overall length would probably not be over 180mm.

Interesting idea!
I would love to be involved in this project, but I’m not sure I have time to do it. Another project will take almost all of my extra time over the next 6-7 months.
But if the job can be done with minor changes to KaupoiMOD v4, maybe I’ll have time to do it. Schematics would help get started.
I don’t know much about electronics, but I like to design and make circuit boards. :slight_smile:


Great Kaupoi. You are the one I was hoping to respond. I do think your v4 would be very easy to adapt to. With the fact that the SPI pins are already in your can header, we could simply just extend the board at the bottom,(USB connection end) and use a ribbon for now. If it isn’t too much changing, I’d love to move the can header onto the extension. The extension would need headers to mount the switch, or something similar and the routing for the regulator beside it, all with a set of pin headers to take SPI from one port of the switch to the GPS board below.
Extension added to your board would need 12v supply, ground, and from nano, mosi, miso, sck, and cs(ss).
It would need enough space for the switch(45x45mm) and regulator, about the same, plus a rj45 Jack.
I will get a schematic of the regulator circuitry.images
This is what I found for a simple 12v to 5v, 3A regulator. Is this usable
I think the 220 would take less pcb space, but whatever you like works

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Do we really need:

  • regulator? Since there is a 5V 2A output at switch already?

  • RJ45 Jack on pcb? Since there is a connector for ethernet cable at switch already? Maybe RJ45 jack could be mounted to the panel of the enclosure and wired to the switch?

The regulator is a must I believe. The 7805 will get hot at over 200ma, I’m told. Everything works well right now and don’t want to create a future problem. I have to add pcb length to add the switch and thers is a blank spot beside it.
There is no rj45 Jack on these modules, just connectors like pixhawh. I do like the idea of wiring it direct to a panel mounted Jack. One less cable
I have searched all afternoon for a switch without terminals, but only one fiber optic is all I found.
I am working on mods now

I can’t see a 7805 on switch module. Description says:" * 5V, 2A auxilliary output onboard." :thinking:
Adding switch module increases pcb length about 5mm :wink:

Maybe there is a misunderstanding on my side now. Need to think over night.

No, you are exactly right. It does have 2a output. I had thought about using it. I will check to see what esp32 and two f9p’s plus radio will draw. That would be great

Esp32 is 44mA max
F9p is 600mA max each
1 watt radio is 800mA max
That’s 2.044A
Makes me concerned. I doubt all would be maxed at the same time, but
These cost 179 and there is another one that is similar, that cost less than 20. I’ll try to get a picture. Either way, for now I like the idea of a ribbon connection for testing.

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You could even use this switching type on the PCB v4.1 and get 1.5 A out of each.
Split power usage between output from 2 A from switch and 2 times 1,5 A from PCB


Just remember to leave enough power for stuff on PCB
WAS has its own 7805 so should possibly be able to share quite some power.
Found at Mouser.
If you demand linear power for WAS then use old fashion 7805 there and the 78SR-5 for the rest including 5 V out

2203475201556 2203477564214
I think the lm2576 uses the 220 style, and the capacitors are left 100uf and right 1000uf. I will try to find out for certain. Can you ascertain the pcb area that this for require from the pictures and component sizes ?

Someone messaged me on the forum today, and said the linear regulator will get hot on heavy draws. I cant remember where it was to say exactly, but he said for powering these modules, I would be better with a buck type converter, though they are a little more noisy. I am running my dual setup off of a small buck converter and it is working well. This particular one that we are looking at integrating with the lm2576 is able to produce 3A, supposedly without overheating. I’m like Kaupoi, I really don’t have a lot of electronics experience, and will appreciate any knowledge offered.
I found the Gerber for this board. I’ll get it on the cloud and get you a link
1810012710012 1813338524764

The 78SR is a small buck converter.

I use linear 7805 on my PCB (v2 type) and they do not get more than “handwarm” even without heatfinns.

Edit: The ones I have are designed for 1.5 A with good heatfinns

Do you know what you are drawing on average ?
This would be so much easier
This one shows 1.5. The enclosed black one shows 1.0

580-78SR-5/2-C This one on mouser is 2A

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Haven´t checked , but my WAS (honeywell) is below 25 mA
Other circuit my guess is max 500 mA probably only 300 mA

You are right the BOM list uses a 1000 mA type, and for normal use that is enough.
With same type of 7805 for both, then no risk of switching places, but I would use L7805 for WAS and a 1.5A or 2 A switching for the rest, if I needed so much power as you plan.
But switching power supply also for WAS seems to be fine.

Yes, the 7805 for ads and was. I don’t want to change anything on the board, just add some things on the end.
This is the 2A. It’s the largest that I found that will solder in direct
Adafruit has this one, is UBEC brand 3A


MP1584 is also good. 10.5 x 16.5 mm.


I am using this (mp1584) in other projects. 22mm * 17mm


I was just looking at this, its 3A, but I hadn’t thought about the header mount. Thanks

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Looks like switch module has this mp1584 on it.

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According to the BRD and SCH of the PCB v4.1(see pictures in the pcbv4 thread), then one of the 7805 powers only WAS, the line is named V+WAS

The other 7805 feeds Nano BNO Ads and 5V out, and also 5V on the CAN pinout.
So at least 3 places to pick up 5V out

But now bottleneck ends up at D2 which could be replaced with a 6A diode.
And maybe make a “high power” 5V out close to one of the 7805 or enlarge some og the 5 V lines so they don´t burn

Nice catch, I didn’t put that together. Wish it was 3A.
Might be able to put the other one on that board.
I’m running in to some trouble finding the botblox module in the US. I’d like to get one and try the 3A power supply together