Introduction - If you have any usage issues, please Google them yourself
DTMF codec in the encoding of digital information when converting keystrokes or dual tone signal and send, decode received DTMF signals when the detected keystroke or the existence of digital information. Using ccs2.2 development. Run in DES5410APP-U development edition. Subroutine _start_ac01, complete the AD and DSP multi-channel buffered serial port (McBSP) initialization. Subroutine _iir_to_dtmf, by the function set_freq_coff () initialization of the coefficient, iterative produce the frequency and column frequency, the subroutine to calculate the value of the two frequency signals samples were placed in the accumulator a, and b, with increase after an audio sample as a new sent. main.c file to complete the process control, including the series of experimental system initialization function, delay function mydelay (), print function.