Building and playing (mainly playing) the Boldport Club Stringy (Project #14, June 2017).
Here's a quick video showing it in action..
Stringy synthesizes guitar sounds on a PIC microcontroller using MadLab's implementation of the Karplus–Strong string plucking algorithm. It can play notes over five octaves.
Stringy is a remix of MadLab's 'Funky guitar'. The code is open source, so I think next up I'll attempt to compile and upload.
But for now, I'm too distracted just playing tunes;-)
| Ref | Part | Qty |
|---|---|---|
| IC2 | PIC microcontroller, Microchip 12F1840-I/P | x1 |
| IC1 | 5V linear regulator, Taiwan Semiconductor TS78L05CT A3G | x1 |
| Q1 | BJT npn transistor, Diotec BC547B | x1 |
| LED1 | 5mm blue LED, Kingbright L-9294QBC-D | x1 |
| S1,S2 | Tactile switch, TE Connectivity FSM4JRT | x2 |
| R1,2,4,6-18 | 1KΩ resistor, Multicomp MF25 1K | x17 |
| R5 | 47Ω resistor, Multicomp MF25 47R | x1 |
| R3 | 1MΩ resistor, Multicomp MF25 1M | x1 |
| C3 | 220µF electrolytic capacitor, Multicomp MCGPR16V227M6.3X11 | x1 |
| C1,C2 | 10µF electrolytic capacitor, Multicomp MCMR35V106M4X7 | x2 |
| C4,C5 | 0.1µF ceramic capacitor, Multicomp MC0805Y104M500A2.54MM | x2 |
| J1 | 3.5mm jack socket, TruConnect 20-0137 | x1 |
| Battery contact positive, TruPower 18-0596 | x1 | |
| Battery contact negative, TruPower 18-0597 | x1 | |
| 8-pin DIL socket, TruPower DS1009-08 | x1 | |
| piece of 20AWG hookup wire | x1 | |
| PCB | x1 |
The microchip PIC12F1840 site has plenty of info and datasheets for the processor. The core specs:
- 7kb flash memory
- 256 bytes RAM
- 256 bytes EEPROM
- 5 I/O Pins and 1 Input-Only Pin
- 4 channels ADC (10-bit)
- 1 comparator
- 2 x 8-bit, 1 x 16-bit timers
- Internal 32MHz oscillator
- stringy - Boldport Product Page
- stringy - on the community site
- stringy software
- Microchip PIC12F1840 - product info and datasheet
- MadLab's 'Funky guitar'
- Karplus–Strong
- ..as mentioned on my blog