The Drawbot works by recieving instructions over a serial link. This code is called GCODE and is designed to be relatively easy for humans to understand.
Most of the gcode will be automatically made for us using a drawing program but there are a few simple codes that it will help us to know.
M03 S000
M03 means we are controlling the pen, S000 sets it to the highest position.
M03 S500
This is almost the same, we are setting the pen position to S500 which is roughly the level we need for drawing although this can vary.
G90 X0 Y0
G90 means we are making a fast move, X0 Y0 tells the drawbot to move to the 0 position on both X and Y.
M03 S000 G90 X220 Y120
Now we are using two instructions at the same time, this raises the pen and moves the drawbot to close to the farthers top right position. This position is useful for when we want to clean the board or change the paper.
It is recommended to put each of these codes into the Macros section of Universal GCode Section as we'll use them often.