HATs and other add-ons • Documentation for POE hat registers

Hello

Is there any documentation for POE HAT registers that are exposed by mailbox tags RPI_FIRMWARE_GET_POE_HAT_VAL / RPI_FIRMWARE_SET_POE_HAT_VAL? By playing around with my POE+ HAT I see four registers 0, 1, 2 and 4. Register 0 and 1 control the fan speed somehow. Register 2 reports quantity in the range 1200-1400 and register 4 reads value 1 (but may be set to another value).

What are those registers for?

Thanks!
ZK

Statistics: Posted by zyga — Tue May 06, 2025 9:47 pm

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