Based on the schematic, the nRF52840 Feather Express uses the same MCP73831/2 lipo charge controller as the m4 express, leading me to believe that the solution described in this blog post for bringing the vBAT up to 4.3v will work and prevent the battery LED from flickering: https://gurunoia.lochan.org/blog/2020/1 ... 4-express/
In my application, I will never be using a LiPo on the JST connector, as the Feather is powered via a big 300ah off-grid lithium battery system through a 5v regulator, which I pass in via the USB port instead. Do you see any possible problems with applying this approach to the nRF52840 Feather Express hardware? (10k pull-up resistor on vBAT to vUSB to bring the charge controller past the threshold voltage for the "No Battery" state per the MCP73831/2 datasheet)
Preventing battery led flicker on nRF52840 Feather Express
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- q_rohlf
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- adafruit_support_carter
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Re: Preventing battery led flicker on nRF52840 Feather Expre
If you can't simply ignore the LED, simpler options would be to add a blob of some opaque putty or glue to cover the LED, or just solder it off.
- q_rohlf
- Posts: 5
- Joined: Mon Aug 16, 2021 2:14 pm
Re: Preventing battery led flicker on nRF52840 Feather Expre
I’d prefer not to modify the feather itself for a number of reasons. It sounds like aside from the ~25 microamps current drain thru this resistor, you don’t see an issue with this plan though?
Aside from the battery voltage divider to A6, it doesn’t look like anything else is on the vBAT net from the schematic.
Aside from the battery voltage divider to A6, it doesn’t look like anything else is on the vBAT net from the schematic.
Please be positive and constructive with your questions and comments.