There's been quite a lot on the forums about people wanting speech synthesisers, with the SP0256 long obselete.
In this months EPE Magazine, Dec 2007, there's a PIC based replacement for it. It uses a 16F628 and a 24LC512, and you can store the original SP0256 phonemes in it, or record your own with a further 16F876 based board, and a VB6 program on your PC.
Perhaps this may be of interest to those who have asked in the past?.
The device is long obselete, and the phonemes can be downloaded from various places on the net - as to them being copyrighted or not?, who knows?, I would imagine they probably came from an American University in the first place and are copyright free?.
It's been a project I've been mulling around in the back of my mind for ages. The SP0256 only had 2K bytes of ROM for it's speech table and there is a single chip clone out there using a PIC (code protected of course)
Have they made the source code available? I thought about doing something like this using a 16F88 and using ADPCM, it should be possible as a stand alone pic. I wonder why they used an external EEPROM when they could have used a bigger pic.
Possibly price, or the smaller chip being more common?
More often than not a cheap PIC with an larger external eeprom is going to be cheaper than larger PIC with an eeprom of equivilant size.
Have they made the source code available? I thought about doing something like this using a 16F88 and using ADPCM, it should be possible as a stand alone pic. I wonder why they used an external EEPROM when they could have used a bigger pic.
Using the EEPROM give 64K of space, so perhaps that's why?.
They always give source code for their projects, although it's not on their website yet as the magazine isn't officially released (I have it on subscription).
The device is long obselete, and the phonemes can be downloaded from various places on the net - as to them being copyrighted or not?, who knows?, I would imagine they probably came from an American University in the first place and are copyright free?.
Just warning you, there have been lots of ROM sites taken down that offer abandonware downloads. You'll probably be fine using the phonemes providing it isn't for commercial use.