UCTRONICS PoE HAT for Raspberry Pi 4, Mini Power Over Ethernet Expansion Board for Raspberry Pi 4 B 3 B+, with Cooling Fan

Product Information

Eben 3:45: And there are PoE modes where you put the power on the spare pairs that are spare in some standards. Dominic 5:55: So the first PoE HAT was only a 13W product, and that had a much more conventional transformer on there.

Dominic 3:18: Through the switch. Yes. And then it applies a voltage to the cable, to then try and detect a resistor of a particular value. And if it can detect that, then it knows which power range available. There are more advanced methods for the higher, for PoE++ that we were referring to, but we don’t do that, so no need to describe how all that magic works.Compared to the HAT, this board is compatible with a Raspberry Pi Compute module instead of a regular Raspberry Pi 4 or 3. Unlike other RPI, on a RPI4 the power LED is fully under the control of a GPIO expander, and when booting Raspbian resets this IO expander so causing the PWR LED to blink off on reboot. On booting the bootloader enables it again. But if the PWR LED goes off (blinks) at any other time it means have an unfit power supply/power cable. in short, the PWR LED should be always on except for a very short time just before a reboot happens. There is one other avenue I'd like to explore. Maybe they're not actually dead. I've tried removing the PoE HAT and powering both of the RPI4s with the official RPI USB-C AC adapter I have. And they both now do the same thing. The little red light blinks a steady blink at about a 1 second interval seemingly forever. I counted off at least 30 blinks that seemed to be exactly 1 second apart from the moment I connected power. I'm not 100% sure what this blink pattern means. I'm kinda confused by the descriptions I'm finding about the blink codes that the RPI4 produces. our board does not have any EPROM id because we want everybody to put their proper HATs on top of our shield

The same thing happened when I powered the Pi via USB-C, so the moral of this story is to use a powered USB hub if you use high powered USB devices. The Pi 4's USB ports can only supply a maximum of 1.2 Amps, no matter how much power the Pi itself gets. Use with USB-C Power Adapters We’ve tested a variety of pass-through headers and can recommend the 2×20 pin header from Pimoroni and the 4-way risers from RS and element14. With the PoE (Power over Ethernet) feature, and versatile onboard peripheral interfaces, it is suitable for evaluating the Raspberry Pi compute module, also is an ideal choice for end products.The Raspberry Pi PoE+ HAT is a new version of the original Raspberry Pi PoE HAT, now with 5V 4A output for the most demanding Raspberry Pi applications! It is designed to replace the original PoE HAT in all new and existing designs and meets all requirements of the IEEE 802.3af (802.3at Type 1) specifications.