Power Input (7-12V)

The Basics

The Arduino Nano Carrier can be powered by a 7-12V battery or supply. The power input is the green screw terminal pair in the lower left-hand corner of the board. Positive and negative are labeled. The board is protected against reverse polarity; it will not turn on if the supply is reversed, but it will not be permanently damaged.

In your kit, you received a 7.4V lithium polymer (LiPo) battery. This battery can serve as the power source for the Arduino Nano Carrier. Please read the battery safety information on the course website before using the lithium polymer battery. To connect the battery to the Arduino Nano Carrier:

1. Strip the JST wire connector included in your kit:

2. Using the screw terminal, clamp the stripped wire ends to the Arduino Nano Carrier with the red wire in the postive (+) terminal and the black wire in the negative (-) terminal:

3. Plug the lithium polymer battery into the JST connector. Always do this last. Do not plug the battery in while the bare wire ends are still loose; it may short circuit:

4. Move the power switch to the on position (right). The power LED on the Arduino Nano (blue) and the Arduino Nano Carrier (green) should both light up:

If the LEDs do not light up, check the polarity of the power connection and that the battery voltage is above 6V.

Reverse Polarity Protection

If you're interested in how the reverse polarity protection works, here is an excerpt from the Arduino Nano Carrier schematic:

The component S1 is a power MOSFET, which is a type of transistor. Like an electronically controlled switch, it allows current to flow when a (positive) voltage is applied to one of its pins, appropriately called the "gate". If the supply is reversed, a negative voltage is applied to the "gate" and the MOSFET's intrinsic diode blocks current from flowing into the circuit backwards.