Answered Powering HE123 with 12v. Seperate 5v PS for BBB through Barrel connector?

KHill9314

KHill9314

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Just chasing some info from any fellow HE123 owners and users.

Planning on powering my HE123 with the same 12v PSU powering some smaller props of mine. After doing some reading of the manual and prodding around the boards, the conclusion I'm coming to is that due to using the 12v for the HE123, I will need to power the BBB separately? If this is the case, just confirming that its as simple as using a 5v 2amp psu via the barrel connector on the BBB itself?

Apologies if this is a dumb question, but would rather confirm before applying power to the boards.

Cheers.
 
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I do not own a HE123 or the MK2, so take what I have to say for what it's worth.

It seems the BB is powered directly from the board.

Looking at the boards, they seem to have a buck converter under where the beagle bone sits.
I am guessing that is used to step down the voltage if need be.

Looking at the manual for the HE123 MK2 (it is the same on the original 123).
There is a three position terminal block for powering the board. It has 5v, 12v, and gnd.

I'd assume the 5v feeds power directly to the BB whilst bypassing the step down converter, while the 12v input feeds through the step down converter before the BB.


Screenshot 2022-03-19 at 11.52.53 AM.png
 
What is said above is correct. There is a smaller terminal strip to connect either 5 or 12v. This will power the Beaglebone attached. There is an onboard regulator for bringing the 12v down to 5v. This allows you to run a permanent power source so the Beaglebone stays on even with the power supplies for the lights switched off. Makes for faster startup of everything each night.
 
Keep in mind that this input (via buck convertor for the 12-24V terminal, or direct via the 5V terminal) not only powers the Beagle but also all of the other parts of the board as well. Best to Feed it from the board, not the Beagle.

The four large power connectors are just for pixel power only.

You have the flexibility in sharing pixel power for the board, or running it independently.
 
I have a HE123mk2. My intention was to power the board and BBB with 12v as I have a 3a 12V PSU in my controller box for my FM transmitter, and a 5V 60A PSU for pixels.

I had my 12V connected to the power input for the board (it is correct that this powers the BBB), to my FM transmitter (CZE05B), my W1209 fan switch, and fan, and the 5V to the pixel outputs.

For whatever reason, my board didn't work on 12V, Allan seemed to think it was a regulator issue, but I didn't both waiting to find out and just ran it off my 5V PSU as it was only going to have 20A pulled from it.
 
There are known issues with the BBB requiring a certain rise time for its power rail to be able to boot, which I believe is exacerbated by running it off 12V and having essentially two power supplies in there (240 > 12 > 5).
I believe the Kulp boards also have a similar issue sometimes.
 
Thanks guys, appreciate the responses 👍 Yeah just wasn't sure about any 12v to 5v conversion so thanks for clearing it up for me 🤙
 
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Skymaster said:
There are known issues with the BBB requiring a certain rise time for its power rail to be able to boot, which I believe is exacerbated by running it off 12V and having essentially two power supplies in there (240 > 12 > 5).
I believe the Kulp boards also have a similar issue sometimes.
Click to expand...
So what is the best direction to take with these?

Run the BBB Off 5V thru the HE123 rather than 12v?
 
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