Sunday, June 12, 2011

Update on the Drawbot

While writing finer control software for the Drawbot I discovered an previously undetected issue with the driver board. It took me a couple of days to isolate and fix the issue, but once I nailed that down the bot really started behaving well. This video shows it with its intended control scheme implemented. There's a Python application running on my pc which communicates drawing commands over the Arduino's USB-serial interface. The Python app calculates an 8 deep Hilbert curve, and translates it into the appropriate drawing commands. The legs of the curve are about 1/4 of an inch long, and have 32 steps each, making the overall resolution of the bot about 128 dpi. Not too shabby for about $65.00 in parts - including the cost of the Arduino.

Tuesday, June 7, 2011

Drawbot makes its mark

This evening I got my drawbot up and running for the first time. The mechanics are still pretty shakey, but the electronics have been burned in for several hours now and I'm pretty confident they're solid. The 'bot is based on an Arduino with a dual axis opto-isolated unipolar stepper motor driver shield that I designed and built myself. As soon as I can figure out a place to put them, I'll post the Eagle files for the shield.

I'm writing a PC application in Python to do some image manipulation and drive the 'bot. When I get it further along I'll post again.