I followed the instructions at on [
dev.www.reprap.org]. And than "Program the Arduino or Sanguino to talk G Code". I downloaded all the files from [
reprap.svn.sourceforge.net]. I am using the DC motor for the extruder, DC Motor Driver v1.1 MakerBot industries circuit and Arduino Duemilanove as a controller. The DC motor is wired to the A+/- output on the DC Driver. The DC driver ground is connected to Arduino ground. The PWM_A and DIR_A is connected to pin 11 and 12. I use oscilloscope on the outputs but there is no change when I press the button on my PC. Thanks.