Official poe hat with hyperpixel 4.0

Hi all,

Is it possible to power the hyperpixel 4.0 with the official poe hat? And if so, are there any best practices for such a combination?

Thanks!

According to its specs the POE hat can deliver the same 2.5A the official power supply can so I would think its doable. Your going to need a stacking header with long male pins.
The 11mm one here may work, I’m assuming the pins can go right through the POE hat GPIO header and extend up the top side.


I can’t find its GPIO pinout but I don’t think it uses anything other than the ground and +5V pins.
You’ll just have to watch the clearance to the POE hat cooling fan. Finding stand offs might be tricky depending on what the final spacing ends up being. I think your going to want at least 4 of the standoffs with the threaded studs on one end. Like in this kit.

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Thanks a billion.

The Poe hat uses i2c for fan control. Would that render a problem? (I’m not that familiar with that protocol.)

Yes, it could be a problem. Devices can share that bus as long as no two have the same address. So it wouldn’t normally be an issue. Problem is the Hyperpixel uses all the GPIO pins and reassigns the normal i2c pins to a different function. There is an i2c header on its back side but I can’t see how you could easily use it with the POE hat plugged into the GPIO.
And I’m not sure what will happen even if you don’t use the fan speed software? I would imagine the POE Hat will be auto ID’s by its eprom and all the software setup automatically? Might have to ask about that on the Pi Foundation Forum. You may be able to disable it from using i2c and just leave the fan running at full speed, or not running at all?

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The Official Pi post says that an additional hat on the POE is possible.

It also links back to the Pirates for which headers to buy (same as the ones @alphanumeric pointed you too).

Cheers,

Simon.

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The hyperpixel is a bit of an exception though. Its not like a traditional HAT. i2c doesn’t work the normal standard way it does on any other HAT. Those GPIO pins are used for something else. That complicates things in this instance.