Chinese o2 sensor

o2sensor.py

#!/usr/bin/env python3

import serial
import struct
import sys

if len(sys.argv) < 2:
	print(f"Usage: {sys.argv[0]}, <serial port>")
	sys.exit(1)

ser = serial.Serial(port=sys.argv[1])

while True:
	startByte = ser.read(1)
	if startByte[0] != 0x16:
		continue	

	message = startByte + ser.read(11)
	if len(message) != 12 or message[1] != 0x09 or message[2] != 0x01 or sum(message) % 256 != 0:
		continue

	# print(message)	
	[o2, flow, temp] = [float(val) / 10 for val in struct.unpack('>xxxhhhxxx', message)]

	print(f"{o2}% oxygen; flow {flow} l/min; temp {temp} degrees c")