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Powering the M0 Feather WiFi via 3.3V source
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Powering the M0 Feather WiFi via 3.3V source

by Mati_Enz on Tue Apr 13, 2021 1:24 am

Hi. I am thinking about integrating the M0 Feather (ATSAMD21 + ATWINC1500) into my portable device. Initially, as the device uses motors, i planned on using a 7.4V power source and step the voltage down to 3.3V for the feather. However, on the Adafruit website it states the feather is not recommended to be wired to an external supply by the use of the 3V pin. I can see this could get problematic, but would it be possible to just connect a stable 3.3V source to the BAT pin? I know i can not use some bat functions, but are there any downsides of this approach?

Thank you!

Mati_Enz
 
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Re: Powering the M0 Feather WiFi via 3.3V source

by dastels on Tue Apr 13, 2021 10:49 am

I would be concerned about the impact on/off the LiPo charger if connecting an external source to Vbat. Powering with 5v vis the USB pin is also not a good idea as when USB is connected there's a conflict since there's no diode on the 5v from the USB.

That said, some hacking on the feather would let you power it using the 3.3v pin: you could decsolder the 3.3v regulator, thus isolating the board's power from USB and battery. That's fairly delicate work, though.

Dave

dastels
 
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Please be positive and constructive with your questions and comments.