June 2000, Issue 119

The Chips are Alive with the Sound of Music
Imitatiing the Dead Melody IC

PERSONAL MELODY

I couldn’t let this discourage me. I wanted to make a special card for my wife this year and I planned to use one of Holtek’s parts for it. I ended up turning a simple gesture into a full-fledged project (see Photo 1).To make a similar device requires a programmable microprocessor. A small 8-pin SMD device would be the perfect size for a Holtek replacement. The only manufacturers of 8-pin micros that I know of are Atmel and Microchip. Microchip’s PIC12C508 does not have interrupts, so it can’t easily output frequencies with stability amidst the other processing that’s necessary. This means the smallest workable PIC is the PIC12C671. Atmel’s AVR series 8-pin micros have timer interrupts available, so the ATtiny10, which is its bottom-end device, is adequate.