Build Your Own Combat Robot

Sensor Integration
FIGURE 13-11
Schematic of a
complete autonomous
mini sumo robot.
Chapter 13: Robot Sumo 293
Integrating the object detector and two edge detector circuits along with a Basic
Stamp 1 can be accomplished on a small prototyping board. Figure 13-11 shows a
schematic of the entire circuit for an autonomous mini sumo.
In a remote-control mini sumo, the same battery pack powered both of the
modified R/C servos and the receiver module. For the autonomous mini sumo,
you need two different power supplies. A 4-cell AA (6-volt) battery pack will provide
power to the modified R/C servos, and a 9-volt battery will provide power to
the microcontroller and the sensors. A 4-cell AA battery box should be attached
to the bottom of the mini sumo. Double-sided foam tape should be sufficient to
attach the battery box to the bottom of the mini sumo.
All battery, microcontroller, and electronic circuit grounds must be tied together.
If the grounds are not tied together, you’ll see erratic performance in the
bot. The reason for the two battery supplies is that the servos can momentarily
draw up to 1 amp of current each. This could cause a voltage drop in the
microcontroller, which will cause the microcontroller to reset. Using a separate
power source for the microcontroller will help ensure a uniform voltage supply to
the microcontroller.
The flowchart in Figure 13-12 shows how logic in this mini sumo should work.
The following program example will make a fully functional mini sumo. This mini
sumo will follow your hand as you move it in front of the mini sumo, and stay on
the sumo ring. Using the information presented here, you will have a working autonomous
mini sumo bot.