Early in 2003 my plans for simple speech output, were growing along with the Lo-res vision system. However the CPU load was rising very fast and even moving to a 386 or 486 motherboard, would have still meant that, I lacked the processing speed to control the mobile and produce speech at the same time. I have tried to keep this project low tech, partly in the hopes that it would force me to be economical, as well as reserving the future CPU bandwidth ( Pentium Derivatives ) for route planning and vision analysis. Having revisited some old projects, I started to review the hardware only solutions again. Historically this would have been a SPO256AL type chip, with a preprocessor to string the allophones together. Time has marched on and the hardware only solutions have improved. Enter the SP03, a winbond powered text to speech processor in a diminutive package only 4.5 cm x 4.5 cm ( including piezo electric speaker ).
The software supplied allows a set of up to 30 phrases to be preloaded, as well as the text to speech availability, via RS232 at 38600 baud, serial ( my preferred interface, in any simple project ). Supplied by Robot Electronics, well worth a visit any day, and one of the suppliers I would recommend without reservation. Now this year, at least, the mobile can answer back.