The WeDo line follower is a line following robot implemented using Lego's WeDo.
The WeDo is a lego robotics kit intended for children ages 7 and under and is much simpler than the NXT and the RCX. It only has two input/output ports, which can be connected to direction sensors, light sensors, or motors.
While a line follower is typically trivial to implement, the lack of sufficient IO connections on the WeDo makes it more difficult to accomplish - because one of the two ports is used for the light sensor, the other one must control both motors. The design is therefore somewhat more mechanically involved, using gear ratios so that the robot turns slightly while going forward and a locking mechanism so that only one wheel can move backwards, allowing it to turn in the other direction when it sees the line.