External power

I have a model C3. I don't see in the manual what the polarity
of the external power supply should be. Is it +5V on the sleeve
or tip/pin?


n.b. did I miss this in the manual?

Hey Gary,

Yeah it’s in there, but it’s not obvious and they don’t use the typical symbol to demonstrate it.

I have a rev C3 board also. I pulled this from the C4 documentation page 45, but it’s the same for the C3.

8.2.2 Wall Supply Source
A wall supply can be used to provide power to the board. A regulated 5V DC supply of at
least 500mA is required. It needs to have a 2.1mm plug with a center hot configuration.



C4 has the center pin as “+5V” and the sleeve is “common”. I verified that the sleeve was indeed connected to the board “ground” using my multimeter before connecting a power supply.
I can’t imagine that this changed between rev c3 and c4. East

It is center hot.