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geoffwatts/sds011.py

Created January 25, 2016 22:57
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  1. Geoff Watts created this gist Jan 25, 2016.
    28 changes: 28 additions & 0 deletions sds011.py
    View file
    Original file line number Diff line number Diff line change
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    #!/usr/bin/python
    # -*- coding: UTF-8 -*-

    import serial, time, struct

    ser = serial.Serial()
    ser.port = "/dev/cu.wchusbserial1410" # Set this to your serial port
    ser.baudrate = 9600

    ser.open()
    ser.flushInput()

    byte, lastbyte = "\x00", "\x00"

    while True:
    lastbyte = byte
    byte = ser.read(size=1)

    # We got a valid packet header
    if lastbyte == "\xAA" and byte == "\xC0":
    sentence = ser.read(size=8) # Read 8 more bytes
    readings = struct.unpack('>hhxxcc',sentence) # Decode the packet - big endian, 2 shorts for pm2.5 and pm10, 2 reserved bytes, checksum, message tail

    pm_25 = readings[0]/10.0
    pm_10 = readings[1]/10.0
    # ignoring the checksum and message tail

    print "PM 2.5:",pm_25,"μg/m^3 PM 10:",pm_10,"μg/m^3"