Prebuilt backpack for a uno?

Hello All,

I am not the greatest with building circuits, but I can follow instructions with a good ingredient list.

I am trying to find a pre-built board that does the most simple and basic function.

I have

a 3.7v lipo battery with the protection circuit built in
an Arduino Uno

I want something that:

has a USB micro port
Charges the battery
outputs to 9v-12v to power arduino from the battery and/or USB

I am frankly surprised that there are virtually no options for this very simple basic function... what am I missing. I was thinking about building something but I have trouble building good step up converters and using diodes to make proper routing. Frankly I like modules which is why I use arduino instead of pics or etc.

Thank you for your time and help,

Well I found two mods but they are not particularly good for mounting

Any one else have any good suggestions? or schematics?

Why the 9-12V requirement? Any use for that voltage?
A regular mobile phone battery pack comes with a MicroUSB charger port, and a 5V output you can connect straight to your Arduino.
If you ditch the Arduino parts and just keep the ATmega chip & a bypass cap you can power it straight from a 3.7V battery even. You just have to run it at a bit slower speed but the advantage of that is you don't even need an external crystal.

The built in protection circuit that is included in some (but importantly not all) Lithium batteries does not have a cut-off that is safe for long term useage.

To properly and safely integrate a Lithium Polymer battery into a product needs external circuitry that both limits the high voltage (which could be the charger) and cuts off the battery when it drops to between circa 3.3V to 3.0V.

Does it all have to be on a single board?

Is this the sort of thng you are looking for;

google uno lipo shield

Tom... :slight_smile:


Yes that would be good a shield like that might work. I wanted a step up to 9-12v to power the arduino fully, I found if I just use a +5v on the VIN it will act funny.

I haven't tried adding a +5v to the "+5v" pin maybe that might work.

I don't want to use just the chip and rebuild the arduino because I would rather have a factory built one.

I can try this shield for the uno, but now I need a similar device for a Nano... Any thoughts?
Why is this so hard...?

You do not put 5V in to Vin, you put 5V into the 5V pin.

Vin is the same as the DC socket on the board, it goes to the on board 5V regulator.

The circuitry on the UNO board allows you to connect a 5V supply to the 5V pin to power the board.

5V to Vin will mean the UNO 5V circuitry is getting a lower than 5V supply that isn't regulated.

Tom... :slight_smile:

Why is this so hard...?

Because of your plug and play like requirements?