code: function hex2elv(val) {
      let i = 0;
      let ret = '';
      while (i < val.length) {
          const h = val.substr(i, 1);
          const d = parseInt(h, 16);
          if (d >= 0 && d <= 15) {
              let cl = d & 3;
              let ch = d >> 2;
              cl++;
              ch++;
              if (i && (i % 2 === 0)) {
                  ret += ' ';
              }
              ret += ch.toString() + cl.toString();
          } else {
              return false;
          }
          i++;
      }
      return ret;
  }
docs: Hex2elv() by Uwe Langhammer