Sumobots
The club currently has three complete sumobots which in the past have been used in intervarsity competitions. We are currently working to upgrade both the hardware and software on these sumobots. We are now using 3D printed chassis to improve weight and performance, and are also working on adding better sensors so that they can be more aware of their surroundings. With these changes comes the need for software upgrades too, so there will be both hardware and software aspects that should be tackled.
Wiring
Starting with the battery connection, the red and black connector on the green nimh battery should match that of the connector on the dc-dc boost converter.
The purpose of the boost converter is to keep the voltage supply for the sumobot constant even as the battery voltage drops, which will happen through draining the battery pack. It is important to set the boost converter correctly before attaching it to the electronics and in particular the arduino. The boost converter uses a small screw to adjust the voltage up or down.
To check this use a multimeter which can be found on the bench to read the voltage across the output pins of the converter when it is connected to the battery alone. The correct voltage should be set at around 5.5v to 6v. Use the screw on the converter to adjust the voltage as required.
The output of the boost converter, once set to the correct voltage can be connected to the motor shield. The motor shied is the larger board which fits on top of the arduino. There is a screw terminal mounted to the side of the shield for this. Note the markings beside the terminal marked v+ and gnd. The out+ wire of the dc dc converter is to be connected to the v+ terminal and the out- to gnd.
Once this is done, its time to connect the motors. The shield is designed with four screw terminals for dc motors, marked m1 through m4. You can use which ever combination of these you like though in order to protect the driver chips on the shield from over heating it is strongly recommended to use one on either end of the board, not two located side by side. For instance, using m1 and m3 or m2 and m4 would be better practice than using m1 and m2.
The motors for each side need to be connected in series so as they will both turn at the same speed at the same time. To do this, take two motors, and connect one wire of each to each of the two screw holes in the screw terminals of the terminal you have chosen. This should mean you will have two motors with one wire free and one screwed into the motor shield. Next step is to wire the two free ends together, this can be done using either a servo extension cable or a female to female jumper wire both of which will be available.
Once this is done, the same process of wiring the motors needs to be done for the other two motors, remembering to connect the second pair of motors to a screw terminal on the opposite end of the shield as the one you just finished wiring.
Once this is done you have the basis of the sumo bot complete, now you have the choice of adding whatever sensors you like to the robot, such as distance sensors and line sensors. These will be wired up using jumper wires and can be connected to the header pins located on the motor shield towards the bottom right corner.