I wanted to get a small robot for me and my son to play with, I originally looked at the Fez Mini Robot kit but it was out of stock at the time. So I did a little digging. Since I already have a Several Dominos I thought I would just build one myself. I found a chasis that looked nice here http://www.seeedstudio.com/depot/2wd-arduino-compatible-mobile-platform-p-657.html?cPath=170_172 so I thought I would just get a motor controller shield that was on sale for a great price and go that way. Well in the mean time the robots came in stock and the motor control shield is out of stock. So I guess I could just get the robot, but since I started down the road to build my own I want to continue that way now.
I’m a little into RC so I thought why not just use a brushed electronic speed controller for the motors. Hobby King has a 20 amp one for $5 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9090 since I already have a couple of these I thought why not just use them for the motor controllers. They are controlled just like a servo so I could just control them with a pwm pin. One for each motor and I’m ready to go.
The only problem is that they expect to be connected to a RC receiver which powers up and holds the servo in a neutral state. So I’m not sure what will happen while the Fez is booting. To alleviate that problem I will add a relay to the power lead of the ESCs. That way the motors can not power up until I “turn them on” with the relay.
I plan on connecting an xbee to talk back to my computer for control.
Any thoughts or glaring problems with this concept?