Help me with keypad to mobile interface

/*--------------------------------------------------------------------------
  Read Keys
  ------------------------------------------------------------------------*/
void read_switches(void) {
  static uchar kbuf[3];
  uchar code keycodeconv[22] = {   51, 52, 53,
                                  1 , 2 , 3 , 4 ,
                                  5 , 6 , 7 , 8 ,
                                  9 , 0 ,54 ,55 ,
                                     56 , 57    ,
                                  58,59,60,61,62
                               };
  find_key();
  kbuf[0] = kbuf[1];   kbuf[1] = kbuf[2];   kbuf[2] = kd;
  if (kbuf[0]==0xff && kbuf[1] != 0xff && kbuf[1]==kbuf[2]) {
    key_data = keycodeconv[kd];                  // valid key edge detected
  }
}

/*-------------------------------------------------------------------*/
void find_key(void) {

  kd = 0xff;

  R1 = 0; if (C1 == 0) kd = 0x00;
          if (C2 == 0) kd = 0x01;
          if (C3 == 0) kd = 0x02;
          if (C5 == 0) kd = 0x11; R1 = 1;

  R2 = 0; if (C1 == 0) kd = 0x03;
          if (C2 == 0) kd = 0x04;
          if (C3 == 0) kd = 0x05;
          if (C4 == 0) kd = 0x06;
          if (C5 == 0) kd = 0x12; R2 = 1;

  R3 = 0; if (C1 == 0) kd = 0x07;
          if (C2 == 0) kd = 0x08;
          if (C3 == 0) kd = 0x09;
          if (C4 == 0) kd = 0x0a;
          if (C5 == 0) kd = 0x13; R3 = 1;

  R4 = 0; if (C1 == 0) kd = 0x0b;
          if (C2 == 0) kd = 0x0c;
          if (C3 == 0) kd = 0x0d;
          if (C4 == 0) kd = 0x0e;
          if (C5 == 0) kd = 0x14; R4 = 1;

  R5 = 0; if (C2 == 0) kd = 0x0f;
          if (C3 == 0) kd = 0x10;
          if (C5 == 0) kd = 0x15; R5 = 1;
}