A couple of years ago I started getting into Picaxe microcontrollers, and I ordered a bunch of random components to experiment with. Turning these funny little spring-mounted motors on and off, I thought, Hmm — I could put a stick on that and let the microcontroller drum! This mini sound-recorder board? Hey, if the robot is drumming, it could record itself and play a new beat with the first one in a loop. Oh, nice yellow tracks, a rangefinder — cool, it could move around and look for things to drum on.
Yellow Drum Machine
Build a funky little free-range drumbot that roams, makes beats, and samples.
- Header pins, male, snap-off (4)
- Wire, stranded, 18–22 gauge, 3' (1)
- Female-to-female jumper wires (15) Yellow is nice, to match your robot.
- Battery holder (long), 4×AA (2×2) (1)
- Heat-shrink tubing (1) Choose colors to match your design.
- Cable ties, various sizes and colors (1)
- Adhesive tape, double-sided (1) either foam or thin
- Epoxy, quick-setting (1)
- Rechargeable AA batteries, 1.2V (4) These need to be 1.2V -- standard 1.5V alkalines might fry your robot.
- Metal washers (4) to fit over the axle
- Aluminum or other tubing, ¼' (6.4mm) diameter × 4' (10cm) (1) for front wheel axle. Use the same tubing as above or something heavier. I like to cut pieces from old radio antennas.
- Speaker, 2', 16Ω (1) Jameco Part no. 1956590 or 99996
- Sound recorder module (aka sampler board), 20-second (1) such as item #PPM155 from techsupplies.co.uk, or #276-1323 from radioshack.com. The Tech Supplies module's buttons both have wire pairs you can connect to easily. With RadioShack or other modules, you'll have to solder a wire to button pads on the circuit board.
- Solarbotics GM10 pager gearmotors (4) These can only turn some 40 degrees to one side, and some 50 to the other. And when they are powered off, they jump back to where they started, because of the little spring. They are also quite strong for their small size, and I use them to drive the 3 drum sticks, and to turn the robot's head. http://www.solarbotics.com/products/gm10/
- Motor driver chips, L293D (2) Jameco Part no. 1341966 - L293D
- Ultrasonic distance sensor (1) Devantech SRF05
- Solarbotics Gear Motor and Tread Package, GM9 (143:1, 90° shaft) (1) A kit with both geared motors and the original tracks can be found here: http://www.solarbotics.com/products/gmtpkg/ (Option: 143:1 offset shaft)
- Lightweight fiberglass rod, very thin, about 6' (15cm) (1) for the 'hi-hat' drumstick
- Lightweight tubing or rod, fiberglass, carbon fiber, or hollow aluminum, about 1' (30cm) (1) for the 'bass drum' (tail) and 'snare drum' sticks
- Flat wooden sticks (1) such as paint stirrers, popsicle sticks, etc.
- Picaxe-28X1 Starter Pack (USB) (1) http://www.techsupplies.co.uk/epages/Store.sf/en_GB/?ObjectPath=/Shops/Store.TechSupplies/Products/AXE001U - PICAXE 28X1 microcontroller in a 28pin project board (AXE 020 board, with both a Darlington output buffer, and a place for one L293D motor driver) and an AXE027 download/programming cable.