GEMMA + LiPo Battery question

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protechcaraudio
 
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GEMMA + LiPo Battery question

Post by protechcaraudio »

Does the GEMMA's onboard USB port charge a connected LiPo battery or must the LiPo be charged externally?

If an external charging circuit is required then can wire the GEMMA's battery connector directly to the load side of the LiPo charging circuit?

My goal is to leave the battery/charging circuit/microcontroller permanently installed in the device needing to only be plugged in for charging.

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adafruit_support_mike
 
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Re: GEMMA + LiPo Battery question

Post by adafruit_support_mike »

The Gemma's ATtiny85 doesn't know how to charge LiPos, no.

Either of these charger breakouts will do what you want though:

https://www.adafruit.com/products/1904
https://www.adafruit.com/products/1905

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protechcaraudio
 
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Re: GEMMA + LiPo Battery question

Post by protechcaraudio »

Thanks, thats the one I ended up getting!

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mlemos
 
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Re: GEMMA + LiPo Battery question

Post by mlemos »

Hi,

Is it possible to use one of those breakout charges and have it permanently connected to Gemma, in a way that it will charge the battery when plugged to USB and power the Gemma when not connected to USB?

What is the correct wiring for that>

[]s

Manoel

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adafruit_support_mike
 
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Re: GEMMA + LiPo Battery question

Post by adafruit_support_mike »

It's possible, but you'd have to solder taps onto the parts on the PCB.

This board is designed to charge a LiPo when USB is connected and power the board when it runs on its own:

https://www.adafruit.com/products/2124

You'd have to make connections to the Gemma's 5v and VBAT lines though, and they aren't broken out to pads on the edge of the board. The only places you can connect are these solder pads:
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1222-01.jpg (67.59 KiB) Viewed 1439 times

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TopHatRaver
 
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Re: GEMMA + LiPo Battery question

Post by TopHatRaver »

Do you have a listing of which boards have lipo charging available on them via the USB? I'm not comfortable doing my own soldering onto the Gemma as shown here. One of the greatest challenges I have with your website is trying to find the right controller for the project that I'm working on. I basically have to hunt and peck to try to find the one what has the features I need. There's no filters or listing of features to make this any easier....something that I'm sure would help many of your customers.

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adafruit_support_mike
 
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Re: GEMMA + LiPo Battery question

Post by adafruit_support_mike »

All of our Feather development boards have built-in LiPo chargers. None of the others do.

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TopHatRaver
 
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Re: GEMMA + LiPo Battery question

Post by TopHatRaver »

Does the Adafruit Pro Trinket LiIon/LiPoly Backpack Add-On work with the regular Trinket 5V or 3V?

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adafruit_support_mike
 
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Re: GEMMA + LiPo Battery question

Post by adafruit_support_mike »

You can connect the LiPo backpack to either Trinket, but the connections don't line up the way they do on a Pro Trinket. You'll have to run the connections with wire instead of pin header.

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