This Project is Mini Synthesizer, using a PICaxe. It was designed by Brian McNamara. If you're looking for a mini drum machine, you should check out his other project, The GrooveAxe
. His other project is the MemAxe
You can get the kit from Gadget Gangster
& grab the schematic. here
. The kit comes pre-programmed. But, if you'd like to gather the parts yourself, you'll need the following.
- Resistors, 1 each of : 1k, 3.3k, 330, 560, 100k, 2.2k, 220k
- 4 x 10k Resistors
- Gadget Gangster project board (half board)
- 10 uF Cap
- 8 Pin Dip Socket
- 3xAA battery holder (and batteries)
- 10k Photoresistor
- Micro Speaker
- 22Ga Hookup wire
- And a programmed PICaxe 08M. You can get the Source Code off Gadget Gangster
You'll also need a soldering iron, solder, and wire cutters.
Here's a little video demonstration
How to Play It
The NoiseAxe will play 8 different notes, each note is played by touching one of the 8 resistor legs at the bottom right of the PCB with the stylus wire. You can change the level of modulation by varying the light that enters the photoresistor, creating a vibrato effect. This is done by putting your finger over, or shining a small LED torch onto, the photoresistor.
How it Works
The NoiseAxe is based around the Picaxe 08M micro-controller. The 8 different notes that it will play are controlled via a stylus that you use to touch each of the 8 resistors legs at the bottom right of the PCB. Each resistor makes a voltage divider that produces a different voltage when that resistor is touched. The voltage is sensed by the ADC (analog to digital converter) on the Picaxe and converted into one of 8 values in the program. The 8 note output corresponds to one octave on a keyboard. The sound command is then used to output the correct note to the speaker. The photoresistor is also used in a voltage divider circuit connected to one of the inputs the micro-controllers ADC. A digital value is read within the program and added or subtracted from the frequency sent to the sound command.