I recently ordered a Zumo robot shield manufactured by Pololu and found it to be a great little robot.
It comes preassembled and has various integrated sensors and actuators, including a 3-axis accelerometer, a 3-axis magnetometer, a Buzzer, a motor driver, an IR reflective sensor array, amongst others.
It comes with 2 75:1 HP micro metal gear motors, so it has a fair amount of power for such a small robot. The robot is within the 10cm x 10cm size limit of most robot sumo competitions, and with its very low centre of gravity combined with its speed and power it would be a serious competitor.
An Arduino Uno R3 acts as the robots’ brain and simply slots onto the top of the robot, exactly like any other shield. All programs are then loaded onto the Arduino Uno as per normal and Pololu provides various example programs, including line following, maze solving and robot sumo programs.
The robot has an expansion area through which some pins are exposed that can be used to integrate some additional sensors and actuators.
I am looking forward to customising this robot and seeing how much more I can expand it.
I will write more about what I am doing with this robot in a future post and I will also be posting a video of the robot in action on my Youtube Channel in the near future.