A couple of months ago, as I was checking the gifts we received for the birth of my son, among piles of clothes, bodysuits and socks, I noticed a very cheap red remote control cable car. I opened the box and while I was inserting some batteries, I was thinking about who is still playing with this kind of toys nowadays. I am referring to the fact that with this toy, you have to chase the car all the time, since the cable restricts you to a distance only one step away from it, and I can tell you that this is pretty inconvenient.

Anyway, I thought that it would be cool if I could turn the car into a fully wireless vehicle, and use my andoid smartphone to control it over Wi-Fi. I had in my posession a Wi-Fi module we used for a project at my company. The Wi-Fi module is made by eConais (www.econais.com), it is a self-contained Wi-Fi subsystem with an embedded cortex M3 processor, implemented TCP/IP stack, WPA supplicant etc, and the coolest part is that the user has plenty of space to write his own application on top of this stack which is given as a library. All the known HW interfaces are exported, including a PWM interface that I used to interface my car's motors. The library exports a very user friendly interface for the Wi-Fi connectivity part, and also the well known BSD sockets.

After finishing with the HW, it took me about one day to develop a very simple application for my Android smart phone and be able to communicate with the car (the car was configured as software Access Point) and that was it! Using your thumb you control the speed, by double-tapping on the screen you switch from forward to reverse and vise versa and by turning the phone left/right like an F1 driver you control the direction. And by pressing the volume up/down you make some leds flashing!

There would be some interesting extensions to this project like adding a camera and see what your car is seeing and many more...