function [k0,g_low,L,g_high,H]=dtmf_detector0L=[23,25,28,31];H=[39,43,48,53];load dtmf_data_0;g_low=abs(goertzel(HT(1:256),L)).^2;[y_low,index_low]=max(g_low);g_high=abs(goertzel(HT(1:256),H)).^2;[y_high,index_high]=max(g_high);key=['1','2','3','A';'4','5','6','B';'7','8','9','C';'*','0','#','D'];k0=key(index_low,index_high);