I decided to achieve an old dream : I am creating a robot (or kind of a robot for the moment).
So I am using my Raspberry Pi that I recently bought, and for which I succeeded to build a cross compiler (that was y previous post). I made a small home-made extension board to plug on the RaspPi. This extension board provides the power from a 12V battery to the 5V needed. And it also has 2 connectors for servo-motors; it will for sure have more components and connectors later.
On the other part, I bought an electric RC car. It is a 1/16 model with a brushless motor. So it is the perfect size to embed a Raspberry Pi on it, and it is surprisingly very powerful (it says up to 70Km/h, I did not try). The battery of the car is big enough to power the RaspPi, and I event think that compared to what consumes a brushless motor, the 700mA of the RaspPi are not a big deal. (here is a link to this car : http://www.funrctoys.com/eShopWeb/product-9022-HBX_BRUTAL_1_16_BRUSHLESS)
For the first version, it is not really a robot. I made an iOs application so I can control the car with my iPhone. And after several weeks, I must say it works ! Well, it still needs improvement for sure, but the prototype works.
For the RaspPi software, I used an existing servo-motor driver (you can find it here https://github.com/richardghirst/PiBits/tree/master/ServoBlaster), I will try to do it myself later. My software communicates through sockets with the iPhone; I have one udp socket for the car to send its “alive” status, and allow the iPhone to discover it on the network; and another socket, tcp, to send commands from the smartphone to the car. Quite simple, and it works.
Here is a video of one of my tests; I am controlling the car with my iPhone. You can see there is a lot of lag, but I know where it comes from, and I am working on it.
More to come soon I hope …