For starters - I know there are perfectly working IC:s for decoding the DTMF and that those are very easy to use.
I have more than 300 Atmega32 MCU:s sitting on my shelf and not a single DTMF decoder.
So I really did a search to this forum and found a zippo. Googel, however, revealed the following thread:
There was an interestinng document, actually a TI application note which contains some assembler code to do this. The assembler is not for AVR but I don't think it will be a big issue to convert it to C.
So, my question is: Have You ever fiddled with software-only DTMF decoder? Any luck with it?
I am NOT asking for code - I am just asking for trouble - or merely early warnings. Be aware though - I am a stubborn idiot who does not take warnings too seriously.
Edit: I was really considering to start this in another part of this forum - but as I will do this in GCC - I thought that this is a proper place after all. However, feel free to move this to another place if needed.