Robot Arm: Testing the Computer

     To run the robot arm with a computer, we first needed to make sure the computer could send and receive signals. Since the Macintosh does not have a physical serial port, we used a USB to serial cable that we connected to the physical serial port on an older PC. Then, using terminal emulation programs, which allow you to send and receive signals out the serial port. We set both of the programs to accept ASCII characters, as that is what the robot arm uses, then successfully transmitted a signal to the PC using the Mac, with the same speed and conditions required by the robot arm(115.2kb/s, 8 bits no parity).

Here, you can see that the message that was written on the mac was successfully delivered to the PC using the terminal programs.

     We later used the same method to test if our simple program to control the arm was working. It was better to use the PC to test the program, rather than the arm itself, because we can actually see the signals our program is sending. We used RealTerm on the PC ( download at http://realterm.sourceforge.net ) and CoolTerm on the Mac ( download at http://freeware.the-meiers.org/#CoolTerm ). Both are free and work really well.