Controlling the LEGO brick via computer: the beginnings of the kiwi drive
|April 6, 2011||Posted by Guillaume under Ground robots, Programming, Testing||
The only tests we’ve done so far with our omnidirectional robot was using some applications (found the android market) so as control the LEGO brick with the basic LEGO firmware. It was indeed working properly (cf our previous articles and videos) but those softwares weren’t designed for the kiwi drive1 we want to use in our project and the firmware (LeJOS) we’re using on the LEGO bricks. But, before going even deeper in this article, you may want to be told a little bit more about this notion. The kiwi drive (a.k.a. the Killough Platform) is just the structure of a omnidirectional robot with three omniwheels. According to the preferences of the developers, the number of omniwheels are either three or four in the majority of the construction (even if some fanciful but impressive constructions require an unusual number of owmniwheels…).
So the first step was to ensure a connection between the brick and the computer via Bluetooth. After that, we enabled the robot and the computer to communicate exchanging strings. The last step of this procedure was to code (on each side) a communication protocol based on string analysis/keywords matching. Thus, you’ll see on the left video below how easy we can control every motor using simple commands on the computer and some driving test on the right one.
|Testing the motors with command lines||Demo of the driving skills of the robots|
Nevertheless, the robot doesn’t have an omnidirectional behavior yet: indeed, we expect the robot to be able to move toward any direction without making any rotation. Our first tests on this feature seem to be promising, but there’s still a lot of development to do to make it work properly and smoothly. You’ll be soon informed about the outcome of our experiments…