I'm trying to get back to programming my Arduino boards and am attempting to make sense of circuits breadboarded in 2013. One of the circuits uses a Funduino Pro mini which I believe is a copy of the Arduino Pro Mini. From doing some searches for info, it seems there are two variants of this board, 3.3 V and 5 V. My question is what is the function of the 5V, Vin and Vbus pins? From what I can establish, Vin (marked as Vcc on some versions of the board) is the raw input which can be up to 12 volts. Is the 5v pin a 5V input, a 5 volt regulated op, or both? (so 5 volts connects to the o/p of the 5 volt reg internally?). Is Vbus the same as Vin? How do I know whether a board is a 3.3 volts or 5 volt version?
I guess Vbus is for powering the board from USB during programming. But is it connected to the 5v pin? Don't really want to do a continuity test because the voltage produced by the DMM may damage the chips.
5v on the silkscreen would also indicate a 5v board.
I do continuity tests on unpowered boards all the time, and have never damaged a board. The current they can supply when doing a continuity test is very low, and it's current that does the damage. I'd try to trace out the circuit and see what its connected to.
Are there any other pins present on one board but not the other?
No just Vin, which is in the same position as Vraw on "real" Arduino boards and Vbus in the same position as Vcc.
According to the documentation here, Vcc is the regulated 3.3 or 5 volt supply (that's what it is on the schematic, but is it also an input?). And what's the story about it being possible to power via the 6 pin header?
I think someone posted a reply to this query before, but all my posts from 6 years ago seem to have vanished.
As regards the DMM, by concern was not really the current, but reverse biasing junctions in the electronics with excess voltage.