SERVO – December 2007 – HERO gets a new voice

SERVO December 2007

SERVO December 2007

This was one of my most popular articles in SERVO magazine.  The project covers how to emulate an old SC-01 speech chip using a more modern speech chip and a microcontroller as a translator.  The end result is a plug in replacement that acts like the original.   There were many challenges that were overcome to make this project.  For every roadblock there ended up being a way around it and all of those are discussed in the article.

Some of the challenges in replacing the SC-01 with a SpeakJet is that they have a different footprint, they have different voltage levels, they have different handshaking signals, one has a parallel interface while the other has a serial interface, and finally the speech codes are different.

The prototype was built using a Parallax SX28 Protoboard and a SpeakJet speech IC.  Eventually the whole thing could be shrunk down to fit on a small hybrid DIP module as a direct replacement for the original SC-01 chip.