-
It doesn't I'm afraid (there's no 5v regulator) - the VBAT pin is battery or USB volts, so you need to be careful there. There's actually the circuit diagram of the power supply here: espruino.com/Pico
Given this is the only big thing you thought I got wrong, I had enough confidence to wire up 10V to the
BAT_INand check it with more than just USB coming in, you are of course right :)I've had a look at that power diagram a couple of times, but without knowing more about how it worked I couldn't really get much out of it because the pins on it are
VBAT,5VandVDO- given they're not referenced like that anywhere else on that page it's not obvious (to me) that they were pins so I'd originally assumed this was somewhere in the middle of the circuit and hadn't realised I could easily probe any of those points.Given the little business card that comes with the kit, the board itself and the schematics all have different names for these pins - do you think that a section could be added to that page clarifying which pins have changed names over time and what those various names are?
You are reading a single comment by @Gordon and its replies.
Click here to read the full conversation.
DavidSchoen
@Gordon
It doesn't I'm afraid (there's no 5v regulator) - the VBAT pin is battery or USB volts, so you need to be careful there. There's actually the circuit diagram of the power supply here: http://www.espruino.com/Pico
Afaik the MCP1703T will handle 400mA peaks, but only 250mA constantly (even at that it's likely to get toasty regulating down from 16v though). I think it depends what you're doing - if you have devices that will run from whatever battery volts is then I'd run them off battery volts, but if you're running some very heavy duty 3.3v stuff then I'd go for an external regulator.
However, the obvious 3.3v regulators have a ~4mA quiescent current (so drawn all the time), so if you're going after power consumption I'd avoid them. A few regulators have an enable pin though, which could be very useful - allowing you to actually turn off stuff that isn't needed.