RAK2287 Pi hat voltages questions

I’m attempting to use the RAK2287 Pi hat with a device other than Raspberry Pi but unfortunately online documentation does not answer all the questions I have. Namely I’d like to find out the following:

  • Are the GPIO, SPI, and UART signals coming out of the Pi hat translated to 5V or are they the original 3V3 of the concentrator?
  • Is the on-board 5V->3V3 regulator linear or switching (i.e. what kind of power losses should I expect?)


Not an official answer, but a pi uses 3v3 I/O, not 5v I/O. The inductor and associated components of a switching power supply can be seen next to the GPIO header, and there’s no evidence of the large package and heatsink that a linear regulator would need.

You may want to gain some experience test-running this on a pi first before re-locating it to your custom host. Having seen everything in operation first is likely to save you a lot of time and frustration compared to tackling many new problems at the same time. And you can get a lot more help with concentrator-related issues while you are still using the expected host system, than you’ll be able to when everything is custom from the start.