This project was created for the Gold Coast Science fair. It is basically a proximity detector that fires an “Exterminate!” through the speaker and lights up the gun when an intruder comes in it’s way. It was the most popular exhibit at the fair and the next phase will be to make it move!
Firstly if you are too young to know what a Theremin is – head on over to the Wikipedia page to find out more. In a nutshell, the Theremin is a musical instrument that can be played without physical contact by the musician.
The original Theremins used radio antennas but our version is considerably simpler using a simple LDR (light dependent resistor) to detect how close your hand is and change the tone on the speaker accordingly. We also added a battery (using an old camera battery – these things last forever on Arduino projects as they have very high mAh values) and an RGB Led for extra effect.
SimpleBot is a super-simplified version of the Wombat robot that we used in the Gold Coast TechSpace Discovery Workshops program.
In this version we don’t use the MiniMoto as we only have modified servos which can be driven directly by the low current outputs of the Gcduino. We also use an old mobile phone battery as a power source and the wheels are also recycled.
The bump sensor is merely a resistor bent over and the LED can be used to signal a bump but also nicely doubles as a stabilizer!
Modified servo means the end stops have been removed and the position potentiometer disengaged.
Pin 5 – Servo 1 (middle control line of servo wires)
Pin 6 – Servo 2 (middle control line of servo wires)
Pin 10 – Piezo (option – not fitted as servo noise can mask the piezo sound!)
Pin 11 – Bump Sensor (Connects to 0Volt when bumped)
Pin 13 – Bumped Led via 220 ohm resistor to ground
This project reuses an old Attacknid robot that I found at the local Endeavour Foundation shop. It was missing it’s controller from the top, but otherwise the battery and motors were fine.
GCDuino comes with a MiniMoto shield that we use with the Wombat robots in the Gold Coast TechSpace Discovery workshops. Wombat is a 2 wheeled robot that the kids build and programme to navigate around a room using a home made bump sensor.
The Minimoto shield includes a HBridge that can be used to drive the 2 motors of Wombat – this can be used to also drive the motors of the Attacknid.