Piclist.com became a wiki because my mom had Alzheimer's and because of a guy named Tony Fisher who I don't know from adam. You can read about that at http://www.piclist.com/techref/idea/websites.htm Mr. Fisher had developed a code generator for making digital filters specs into C code, and made it available on the web. Then he died quite unexpectedly back in y2k. His web site is still up, and the little part of his mind that knew how to write code for digital filters lives on, to this day, at: http://www-users.cs.york.ac.uk/~fisher/mkfilter/trad.html You can go there and "talk to Tony" about Butterworth / Bessel / Chebyshev Filters and get some pretty cool answers. In my mind, this is as close to immortality as we are likely to get. But it doesn't change. Tony doesn't learn any new tricks when it comes to generating code for filters. Today, I put some of his code up on piclist.com and got it basically working. This does nothing more than what the page at york.ac.uk can do, but it does things a little differently: First, it will provide a little bit nicer description of what it is doing and it uses get rather than post so you can save a link to a specific filter spec and send it as a link in an email or whatever. For example: will make a Chebyshev filter with ripple of -1 dB of order 5 for Bandpass to process 10000 samples per second with corners at 100 and 200 Hertz. Or so says Tony. More importantly, the source code of the mkfilter program and the gencode program are available from either site. And I can incorporate changes at piclist.com So, for example, the gencode program could be updated to provide more than the basic template that it produces now: - It could be modified to produce actual working code for an '877 or dsPIC. - It could perhaps be improved if there are better ways of making code for some filters. - Options for integer math could be added. I have also started trying to put together a "compile farm" of the free compilers available. For example, compiles with an old version of SDCC. I've gotten permission from BKND and HTSOFT to put up their free compilers but haven't had the time to do it yet. Any comments? Any ideas? Any one willing to help? --- James Newton: PICList webmaster/Admin mailto:jamesnewton@piclist.com 1-619-652-0593 phone http://www.piclist.com/member/JMN-EFP-786 PIC/PICList FAQ: http://www.piclist.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist