For the course Hardware and Physical Computing supervised by Paul Klomp as part of the Media Technology programma at the Leiden University, we created two drawing robots. Each robot was build around an Arduino Uno, and equipped with two wheels driven by DC motors, an acryl paint marker and a colour sensor. They would leave a coloured trail on the white paper they were driving on, and change their behaviour depending on the colours their colour sensor would detect. The result, an evolving artwork created by robots making moves based on simple rules.
As we got a lot of inspiration from websites such as instructables and Polulu, it seems fair to give something back by documenting the steps in the creation process of these artbots.
The bots consisted of the following components:
- Arduino Uno
- Tamiya's Twin-Motor Gearbox (including two DC motors)
- Texas Instrument's DRV8833 Dual Motor Driver Carrier
- I2C Level Converter 5V-3.3V
- Adafruit's Flora Color Sensor with white illumination LED - TCS34725
- 3 LEDs
- Soldering tin
- Wooden wheels
- 15 mm Acrylic paint marker
- Metal holder
- Angle iron
- 2 9V battery holders
- 2 9V batteries [BEWARE: 9V batteries run out really fast, it might be wiser to use a set of AA batteries, or a rechargeble battery)]
- 2mm x 15mm x 1m aluminium sheet
- 1cm diamater wood
- White paper sheets
- Dark paper for the borders
- Bolts and nuts
- Rubber (tape)
- Adhesive tape
- Soldering equipment
- Drill press with circle bit
- Iron saw
The first step is cutting out the wheels (diameter: 5 cm) out of wood using the circle bit on a drill press.
Next, the Tamiya gearbox is assembled following the manual inside. We chose to assemble the gearbox in the slower 203:1 ratio. And unintended advantage being that two little yellow parts we did not need fitted exactly in the middle of the wooden wheels.
The print board is sawn into a bigger (7cm X 10 cm) and a smaller (7cm X 4 cm) piece, which eventually are placed on top of each other. The gearbox is hung on the bottom using bolts and nuts. The metal holder is put into place using the iron angle. 9V batteries holders are stuck on top with tape.
Three ca. 10 cm sheets are cut from the aluminium. Two are used as bumper holders and one as holder for the colour sensor. All are attached to the frame using bolts and nuts.
From another aluminium sheet, we made a bumper to avoid the two robots from collision