Core Electronics Forum

Ultimate Retic Pi

Hi folks

So I am thinking of putting together something to manage my home reticulation. I wanted to go PoE as well (if possible) to reduce the number of cables and I prefer to hardware endpoints than to use wifi.

To that end, I was thinking of the following components:

To that end, I think I would need:




https://opensprinkler.com/product/opensprinkler-pi/

The idea would be to use OSPi and the touchscreen with the browser in Kiosk Mode for the “external” interface.

My main concern is powering this little beauty. So I might need to look at something like this https://www.littlebird.com.au/poe-splitter-with-microusb-plug-isolated-12w-5v-2-4-amp but again I dont think it will be enough power.

Thoughts?

Hi Jarrad,

If you use the PoE hat there will be no need for the PoE splitter. They serve the same purpose, the PoE splitter is taking power out of a PoE cable.

2.5 amps is usually enough to power the Pi and the display.

You need a PoE injector like this one:

Everything else looks good though! Good luck with your project!

Will the PoE hat be able to be used with the OSPi addon at the same time? I get the impression that they won’t.

I’m also concerned that the Pi is meant to theoretically power itself, the display and the OSPi board.

Hi Jarrad,

I see, I had to look up the OSPi. It looks like the OSPi is powered off the sprinkler valve power, with some left over to run a Raspberry Pi. It specifically says that there will not be enough power for a 3B+ and if you choose to use one you will need to power it externally. For this project, I’d recommend using a 3B to keep your power demands down a bit.

Here is another PoE solution that would work for you:


I’m not sure how many amps you can safely draw through a PoE setup, but I suspect that you will be pushing it with both the display and Raspberry Pi.

Hi Stephen

So in theory, the sprinkler valve power + one of the PoE solutions you suggested and a 3B+ or a 3B might do the trick?

Hi Jarrad,

Yes, thats right.

I would use the 3B because it uses less power. There is really no need for the more powerful processor of the 3B+ in this application.

Thanks Stephen!

Looking forward to getting this one off the ground.