started adding UBX protocol

ubx/ubx.py

@@ -0,0 +1,26 @@
+import struct
+
+
+def checksum(data: bytes) -> bytes:
+	ck_a = 0
+	ck_b = 0
+	for i in range(len(data)):
+		ck_a = (ck_a + data[i]) & 0xFF
+		ck_b = (ck_b + ck_a) & 0xFF
+
+	return struct.pack("BB", ck_a, ck_b)
+
+def frame_create(msg_class: int, msg_id: int, payload: bytes) -> bytes:
+	hdr = b'\xb5\x62'
+	frame = struct.pack('B', msg_class)
+	frame += struct.pack('B', msg_id)
+	frame += struct.pack('<H', len(payload))
+	frame += payload
+	check = checksum(frame)
+
+	return hdr + payload + check
+
+
+if __name__ == "__main__":
+	result = frame_create(1, 2, b'Hallo')
+	print(result)