These were fun labs. Here’s how I used the Arduino and a transistor to control an externally powered DC motor (not using the potentiometer yet):
Getting the light to dim with the potentiometer was easy enough, although I was surprised at how the dim the light was, even at full voltage – I should have done more research to make sure I was getting the right kind of light socket and bulb:
Moving on, the next lab was also fun. I enjoyed learning about H-bridges. It took me a while to reason out how exactly the four switches worked together to reverse the voltage provided to the motor. The provided video was helpful. The hardest part was soldering the H-bridge to the pin headers, which I’d never done before. The result wasn’t pretty:
But it worked! Getting the rest of the breadboard wired up was easy enough. The code was easy to understand. With the Arduino’s 3V3 power supply, the motor was tame:
Powering the motor with the external 12V DC power supply resulted in a much more powerful rotation: