Many years ago (in the 1970s) I purchased a text to speech voice synthesizer. It was a box about the size of a typical WiFi router and the back had an RS-232 connector and a speaker/amplifier jack. It was pretty neat and I enjoyed playing with it and eventually I turned it over to my son who was getting into computer programming on an old CP/M machine. I don’t remember the brand and I suspect that they are long out of business. I do recall that it was in the $100 +/- price range. I must have really wanted it because, according to an on-line Inflation Calculator, what cost $100 in 1973 would cost $485.16 in 2010.

Recently I came across a 28-pin integrated circuit by a company called The chip that interested me was the RoboVoice Text to Speech IC (SP0512). I ordered a beta unit before they were being offered for sale so I was graciously offered an early adopter’s discount (the price is now set and the discount probably is no longer available).

robovoice in breadboard

You can listen to a speech sample that I made on This-YouTube-Video It is saying “I sound funny however I cost very little” Hey, It is very robotic and has an accent, but it does cost very little. There is no comparison between $25 and $485.16.

SpeechChips’ Ken Lemieux (the developer) quickly sent me my RoboVoice TTS chip and I bread-boarded it. At first I couldn’t get it to work so I rechecked all of my jumpers – I found one misplaced jumper and when I applied power I heard “Ready” spoken through the speaker (salvaged from an old Hayes modem).

The RoboVoice TTS chip is based upon dsPIC33FJ64GP802 DSP, which operates on 3.3 volts. I use 5-volt logic 100% so I had to scrounge parts to get things running. I am running a LM386N-3 operational amplifier on 5-volts, although  Ken says, in his experience, the LM386N-3 will work well on 3.3-volts. I also used a simpler LM386 circuit than specified by Ken, and substituted some capacatitors with values that I had on hand, but it works!

I don’t have a project for this yet, but I can see some board in my future that speaks,

This entry was posted in audio, audio, Electronics, hardware and tagged . Bookmark the permalink.

2 Responses to RoboVoice

  1. Alex says:

    FYI, it was the “Votrax Personal Speech System”


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