Toddler cars

The JCU School of Engineering has two of these toddler cars, and are looking to kit them out into RC cars for use at show days, etc. These cars were used in CC3501 last year as the main project, however neither of the two teams in the class successfully got the cars going.

The Robo Club has agreed to take on this project this semester, and I will be leading the project. In fact I have already done some work on the project leading up to the beginning of the semester, having designed a relay board for use with an Arduino Pro Mini 5V.

5V Relay Outputs

I used NPN transistor buffers from the output of the Arduino to drive the transistor coils. I did this because I don’t like the idea of the board driving the coil directly (although it should be possible). I feel safer having the inductive coil somewhat isolated from the circuit by the transistor.

Breadboard prototype for Bluetooth relay outputs Breadboard prototype for Bluetooth relay outputs

Milled Board Milled Board

The relays used here are M4-5H, which are only rated to 0.5A. However, the motors can pull up to 3A stall current. Therefore, the relays aren’t expected to last. They do the job, however: for now..

This temporary solution is designed to allow the car to be shown off in order to raise interest from Robo Club members to participate in the project.