Using the robot for the base allows the robot to print a virtually unlimited size. Think football feilds or basketball courts. Maybe the rivals should be on the lookout for a swarm of these thanksgiving weekend next year. the robot also allows the printer mobility, allowing it to travel to a location to print, then move on to another. Wireless is included, so remote control is also possible. Sidewalk art and advertising is also a target-market for this device.
Step 1: IRobot Create
For our simple use we only required a few commands. Upon initialization the 128 command must be sent to tell the robot to start accepting external control. Next a mode must be selected. For full control we send the 132 command to the Create. Note you must send all data to the Create as integers, not regular ascii text. Each command opcode is one byte, the value of that byte is the integer value 128 or whatever. If you were to transmit in ascii or ansi text, each character in 128 would be a byte. For testing or control via PC we recommend Realterm as it makes everything very simiple. You will also need to set the Baud rate to 57600 as stated in the Open Interface documentation.
Now that the Create is initialized, we use the 137 command to drive the robot forward. Wait Distance, 156 is used to stop the robot after a specified distance. The script commands 152 and 153 put everything together and make a simple script which can be run over and over.
iRobot sells what they call the Command Module which is basically a programmable micro controller and a few serial ports which you may use to control your Create. Instead we used a Cypress Programmable System-on-a-Chip (PSoC) combined with a very small x86 PC called the eBox 2300.
The robot has an 18V battery which we will use to power all our peripherals.