Redesigned the Arduino M0

A few months ago I took the arduino nano schematic and modified it to create my own arduino. I was sick of moving wires around everywhere and having them fall out. Since then my custom arduino has worked great, but I want to make another one.

This time I want to use the arduino M0 as a base. I am using a 3.7V battery to power it which is perfect for the 3.3V chip, and the 32 bit architecture should help with performance a lot. I downloaded the Eagle files from the site and have started modifying them, but I wanted to make sure my new schematic is correct for the power and USB interface.

I have attached pictures of my new schematic, as well as the older schematic for comparisons. I feel that I have taken a lot of way but I just only need the necessities for my circumstance. Any input would be great!!

5volt USB > diode > LiPo battery.
You think that's wise?

The MC33269ST-3.3T3 is an obsolete 3.3volt regulator with 1volt dropout.
Needs a minimum of 4.3volt on it's input. A ~3.7volt Lipo can't supply that.

Not sure if you will get a good battery level reading with such high potential divider values, but you will need to do some bypassing at the analog input.

OPs pic.

Tom... :slight_smile:

5volt USB > diode > LiPo battery.
You think that's wise?


And especially unwise without a fuse in place.