// CRC16 in big endian order
const crcArr = new Uint8Array(2);
crcArr[0] = crcByte1;
crcArr[1] = crcByte2;
const buffer = crcArr.buffer;
const datav = new DataView(buffer);
const uint16 = datav.getUint16(0, false); // big endian
byteArr[index++] = uint16 & 0xff;
byteArr[index++] = uint16 >> 8;