VIN and GND to charge battery?


  • Pybytes Beta

    I would like to place the Expansion Board with a mounted WiPy in my peocet device. unfortunately there is not enough space to connect a cable to the USB port.

    Can I simply connect a power source (5 V) to VIN to power the WiPy and charge the battery at the same time?



  • I had simmilar issue using VIN. I can't believe Pycom doesn't provide any schematic for these expansion boards, or atleast proper descriptions on how they can be used. I was also under the impression that VIN can be used as an input, instead of using the USB. There are NO WARNINGS anywhere that you should not be using VIN as an input, while using a battery as a backup. Luckily my house didn't burn down as I soon enough figured out that VIN and the Battery + seem to be linked together...

    I'm new to Pycom's hardware - and thus far really disappointed in the lack of usefull (and up to date) documentation



  • @Corbie
    I guess the easiest is to connect your GND to the GND pin as normal and your 5V to the component pointed by the arrow on the USB input below (which I think is some kind of fuse?)

    Either side of that component will work, maybe the circuit will be more protected on the top part but then it's very easy to short it to the USB connector (which is grounded).

    If you do it make sure to isolate USB connector from your soldered connection with some mylar tape or insulating varnish - as I said above the connector is grounded and it's easy to short it!

    0_1501173974580_iu-2.jpeg


  • Pybytes Beta

    @jmarcelino Thanks for your answer!

    Is there another way to supply the power like the USB port does? I would even solder the cables to the board, but don't know where. Are there any schematics?



  • @Corbie
    No, that path overrides the charge controller chip (BQ24040).

    May be downright dangerous with LiPos because you could then charge the battery at higher currents than expected.



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