Adafruit N20 DC Motor with Magnetic Encoder - 6V with 1:298 Gear Ratio

The first step in a robotics project is getting a motor spinning. Not all motors spin at the same speed due to variations in voltage, environment, and manufacturing. Determining motor speed involves using an encoder wheel with an optical or magnetic counter to count rotations.

This motor simplifies the process with an attached magnetic wheel and two hall effect sensors, eliminating complex wiring. It's compact, fitting into the standard N20 size, and operates efficiently with 4.5 to 6V DC. Connections are straightforward: white and red wires for motor driving, PWM support for speed adjustment, blue wire for ground, and black wire for power. The yellow and green wires provide encoder outputs.

An example Arduino sketch is available, adaptable to other languages, for interrupt counting and speed calculation using a 1:298 gear ratio. The motor uses 6V nominal power, drawing around 100 mA (200 mA stalled), and varying the gear ratio affects torque and RPM, not current draw.