This week I wanted to put something fun together, so I found an RC car and took it apart. Once I had it apart, I made a list of what I would need to have the arduino control the toy. First, I needed a power supply, thus I rigged together a 9V battery hook-up to supply the arduino with power. Next, I looked at the motors of the toy. I found that this particular toy had a motor for driving the back wheels, and a motor for turning the front wheels. Having only one little transistor, a PN2222A, I decided to wire up the car with both motors going to one transistor. This turned out to be a problem because I could not control the motors separately, and the transistor was just not to the right specifications to handle the motors.
Instead, I acquired a few different transistors and resistors to play with. I decided to use a TIP31 first. I used this transistor to power both motors, this is the first robot seen in the video. After deciding to control the motors separately, I used a TIP120 to control the steering. This is the second robot seen in the video, which can go straight, turn, then go straight again rather than continuously turning.
The main problem I encountered was shown using Robot 1.0 in the video. Despite moving quickly, the little motors just didn’t have enough power to let the robot climb a small bump in a carpet. While the robot doesn’t have any sensors, putting it together and programming its movements was fun and educational. Now if only I could get it to go backwards and turn the other direction…