Datasheet

Pinouts

JST Battery Input

There is no battery INPUT pin on the Gemma. You can connect a battery via the JST jack. We have found that Lipoly

batteries (https://adafru.it/cFB), coin-cells (http://adafru.it/783), and AAA's (http://adafru.it/727) work great. You can also

make your own battery input pack using a plain JST cable (http://adafru.it/261). And use a JST extension cable if

necessary (http://adafru.it/1131).

You can plug anything from around 4 VDC up to 6 VDC. That means any single-cell LiPoly, or 3-4 AAA or AA batteries.

This input is polarity protected. Gemma and DotStar LED light up, you're good to go. You can turn off the battery with

the on/off switch, which will completely disconnect power on the Gemma M0.

Power Pads

Half of the pads on the Gemma M0 are related to power in and out: 3Vo , Vout and GND

Vout - This is a voltage OUTPUT pin, it will be connected to

either

the USB power or the battery input, whichever

has the higher voltage. This output does not connect to the regulator so you can draw as much current as your

USB port / Battery can provide (in general, thats about 500mA)

3Vo - This is the 3.3V OUTPUT pad from the voltage regulator. It can provide up to 500mA at a steady 3.3V.

Good for sensors or small LEDs or other 3V devices.

GND is the common ground pin, used for logic and power. It is connected to the USB ground and the power

regulator, etc. This is the pin you'll want to use for any and all ground connections

Input/Output Pads

Next we will cover the 3 GPIO (General Purpose Input Ouput) pins! For reference you may want to also check out the

datasheet-reference in the downloads section for the core ATSAMD21E18 pin. We picked pins that have

a lot

capabilities.

Common to all pads