In this video the comms board and the pen carrier board are connected up and working for the first time. The comms board connects to my desktop via USB, and is connected to the pen carrier board via RS-485. When I send a command out the USB, you can see the transmit and receive LEDs flash, then the pen carrier board responds by changing the servo's position.
The protocol the boards are running over the 485 link is dead simple right now, and not capable of multi-drop communication. So, the next step is to implement a new protocol. The carrier board also only implements binary servo positions up, and down. The new protocol will give the ability to send data through the link, so I can control how far up/down the pen is. With this I'll be able to use brush tip markers, and vary the line thickness drawn by the 'bot.