Connecting a 3.7V motor to Arduino Uno with a MakerShield

Hi there, I have a 3.7V motor, connected to an external supply, already set up on a board. I’m now looking to connect this to an Arduino Uno (see picture), but it’s so long since I’ve done any electronics that I’m a bit baffled about where to start.

I have the Arduino Ultimate Microcontroller Kit to play with, so have built the MakerShield that is included, to use as a motor shield.

It would be brilliant if someone could help give me a kick start as to how to build the circuit.

Thank you for your help.

R

What do you have for transistors?
Does the motor need to spin in one direction only?
How much current does it draw?

Hi there, thank you for the questions.

The motor only needs to spin in one direction, it would be interesting if we could spin it in both directions, but not essential.

The current drawn by the motor is 135mA

I have a transistor that is an NPN 20V 500mA

Thank you for your help!