# Power Over Ethernet HAT for RPI4b

**URL:** <https://community.zymbit.com/t/power-over-ethernet-hat-for-rpi4b/791>\
**Category:** ZYMKEY4\
**Created:** [June 10, 2020, 3:12am UTC](https://community.zymbit.com/t/power-over-ethernet-hat-for-rpi4b/791 "2020-06-10T03:12:53Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Luke](https://yyz1.discourse-cdn.com/flex027/user_avatar/community.zymbit.com/luke/32/340_2.png) [@Luke](https://community.zymbit.com/u/Luke)\
**Post date:** [June 10, 2020, 3:12am UTC](https://community.zymbit.com/t/power-over-ethernet-hat-for-rpi4b/791/1 "2020-06-10T03:12:53Z")

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Hi, I want to add this: [https://www.raspberrypi.org/products/poe-hat/](https://www.raspberrypi.org/products/poe-hat/)

More info: [https://static.raspberrypi.org/files/product-briefs/Raspberry-Pi-PoE\_HAT-Product-Brief.pdf](https://static.raspberrypi.org/files/product-briefs/Raspberry-Pi-PoE_HAT-Product-Brief.pdf)

But it uses the same PIN’s as Zymbit does.

Is there a way to share PIN’s?

I have also ordered the PROTO KIT.

Thanks,  
Luke

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**Author:** ![Phil\_S\_Zymbit\_1](https://avatars.discourse-cdn.com/v4/letter/p/45deac/32.png) [@Phil\_S\_Zymbit\_1](https://community.zymbit.com/u/Phil_S_Zymbit_1)\
**Post date:** [June 10, 2020, 4:01pm UTC](https://community.zymbit.com/t/power-over-ethernet-hat-for-rpi4b/791/3 "2020-06-10T16:01:03Z")

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@Luke

The simple answer is Yes you can use Raspberry Pi POE hat with the Raspberry Pi and Zymkey 4,  
**however** their product does present several mechanical and electrical challenges if you want to use it with ANY other HAT (including Zymkey).

This posting in MakerSpace describes some of the mechanical and electrical challenges, and how to overcome them:

> **[Raspberry Pi PoE HAT - Maker Space](https://www.makerspace-uk.co.uk/raspberry-pi-poe-hat/)**
>
> Raspberry Pi 3 B+ Back in March 2018, a new version of the Raspberry Pi was released; the Raspberry Pi 3 B+. One of the changes on this new board was the addition of 4 extra pins adjacent to the existing GPIO header. These 4 additional pins enabled...

Regarding Zymkey4i specifically;

There is no officially published schematic for the RPi POE Hat - (yes, that’s hard to believe, so if you find it, please share the link with everyone).

There is an unofficial schematic published by Pi-Supply (which is likely correct.)  
[https://learn.pi-supply.com/make/pi-poe-switch-hat-quickstart-faq/pi-poe-pinout/](https://learn.pi-supply.com/make/pi-poe-switch-hat-quickstart-faq/pi-poe-pinout/)

 ![](https://aws1.discourse-cdn.com/standard14/uploads/zymbit1/original/1X/7a77589e33a4a62bfa1517dc7403ac03ea121db7.png)

If we believe this pinout, then there will be no conflict with the Zymkey, which requires exclusive access to pin-7 (GPIO4), and non-exclusive access to pins 3,5 (I2C) +5V power and ground.

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<div class="post-metadata">

**Author:** ![Luke](https://yyz1.discourse-cdn.com/flex027/user_avatar/community.zymbit.com/luke/32/340_2.png) [@Luke](https://community.zymbit.com/u/Luke)\
**Post date:** [June 11, 2020, 2:42am UTC](https://community.zymbit.com/t/power-over-ethernet-hat-for-rpi4b/791/4 "2020-06-11T02:42:03Z")

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Thanks @Phil_S_Zymbit_1, I’ll let you know if I find an official schematic also, for completeness. In the meantime I will try it.