hi
please give me the steps to detect the DTMF tones through with low cost micro controller with out using a decoder ic. and what are the hardware requirements .
its not easy or feasible to do dtmf decoding at software level... its rather too complex project and the controller will never find time to execute the code written if it starts decooding stmf signals.. So it practically not possible without hardware decoders.. if its a question of 8051 then better drop this idea..
The MSP430 solution provided by ckshivaram seems to use a 1.048 MHz CPU clock, in so far, an ATmega can be expected to be able to do it. If assembly coding is required? Don't know.
FvM is correct, but still i have doubts at the back of my mind about it.. but while searching i came across an application note from microchip where they say it is done using pic18f
please find it here
**broken link removed**