// AT command "at"
char cmdAT[]={'a','t',0x0d,0x0a,0};
// AT command "at+fset=0"
char cmdfset[]={'a','t','+','f','s','e','t','=','0',0x0d,0x0a,0};
// AT command "at+cad?"
char cmdcad[]={'a','t','+','c','a','d','?',0x0d,0x0a,0};
// AT command "at+smsg=1"
char cmdsmsg[]={'a','t','+','s','m','s','g','=','1',0x0d,0x0a,0};
// AT command "at+smss?"
char cmdsmss[]={'a','t','+','s','m','s','s','?',0x0d,0x0a,0};

char ansok[]={0x0d,0x0a,'O','K',0x0d,0x0a,0};
// the answer of "at+cad?" 
char anscad1[]={0x0d,0x0a,'+','C','A','D',':',0x20,'1',0x0d,0x0a,0x0d,0x0a,'O','K',0x0d,0x0a};
// the answer of "at+smss?"
char anssmss1[]={0x0d,0x0a,'+','S','M','S','S',':',0x20,'1',0x0d,0x0a,0x0d,0x0a,'O','K',0x0d,0x0a};
char anssmss2[]={0x0d,0x0a,'+','S','M','S','S',':',0x20,'2',0x0d,0x0a,0x0d,0x0a,'O','K',0x0d,0x0a};
char anssmss3[]={0x0d,0x0a,'+','S','M','S','S',':',0x20,'3',0x0d,0x0a,0x0d,0x0a,'O','K',0x0d,0x0a};
//  the answer of "at+fset=0"
char ansfset[]={0x0d,0x0a,'+','F','S','E','T',':','0','x','0',0x0d,0x0a,0x0d,0x0a,'O','K',0x0d,0x0a};