Introduction - If you have any usage issues, please Google them yourself
DTMF (Dual Tone Multi-Frequency) is a single with two specific combination of audio signals to represent a kind of digital signal coding techniques. Two monosyllabic different frequency, on behalf of the numbers, or the realization of the functions are also different. Eight kinds of frequency of use on behalf of telephone on the 16 keys, 10 numeric keys 0 ~ 9 and 6 function keys*,#, A, B, C, D. The frequency of specific composition of reference books. Requirements: (1) According to the keyboard input of symbols, the use of MATLAB have a corresponding DTMF signal (2), respectively, using FFT algorithm and the Goertzel algorithm DTMF signal spectrum and frequency spectrum draw (3) According to DTMF signal frequency spectrum to determine represented by symbols and input symbols unanimously.