examples/luftdaten.py

   1 #!/usr/bin/env python3
   2
   3 import requests
   4 import ST7735
   5 import time
   6 from bme280 import BME280
   7 from pms5003 import PMS5003, ReadTimeoutError
   8 from subprocess import PIPE, Popen, check_output
   9 from PIL import Image, ImageDraw, ImageFont
  10 from fonts.ttf import RobotoMedium as UserFont
  11
  12 try:
  13     from smbus2 import SMBus
  14 except ImportError:
  15     from smbus import SMBus
  16
  17 print("""luftdaten.py - Reads temperature, pressure, humidity,
  18 PM2.5, and PM10 from Enviro plus and sends data to Luftdaten,
  19 the citizen science air quality project.
  20
  21 Note: you'll need to register with Luftdaten at:
  22 https://meine.luftdaten.info/ and enter your Raspberry Pi
  23 serial number that's displayed on the Enviro plus LCD along
  24 with the other details before the data appears on the
  25 Luftdaten map.
  26
  27 Press Ctrl+C to exit!
  28
  29 """)
  30
  31 bus = SMBus(1)
  32
  33 # Create BME280 instance
  34 bme280 = BME280(i2c_dev=bus)
  35
  36 # Create LCD instance
  37 disp = ST7735.ST7735(
  38     port=0,
  39     cs=1,
  40     dc=9,
  41     backlight=12,
  42     rotation=270,
  43     spi_speed_hz=10000000
  44 )
  45
  46 # Initialize display
  47 disp.begin()
  48
  49 # Create PMS5003 instance
  50 pms5003 = PMS5003()
  51
  52
  53 # Read values from BME280 and PMS5003 and return as dict
  54 def read_values():
  55     values = {}
  56     cpu_temp = get_cpu_temperature()
  57     raw_temp = bme280.get_temperature()
  58     comp_temp = raw_temp - ((cpu_temp - raw_temp) / comp_factor)
  59     values["temperature"] = "{:.2f}".format(comp_temp)
  60     values["pressure"] = "{:.2f}".format(bme280.get_pressure() * 100)
  61     values["humidity"] = "{:.2f}".format(bme280.get_humidity())
  62     try:
  63         pm_values = pms5003.read()
  64         values["P2"] = str(pm_values.pm_ug_per_m3(2.5))
  65         values["P1"] = str(pm_values.pm_ug_per_m3(10))
  66     except ReadTimeoutError:
  67         pms5003.reset()
  68         pm_values = pms5003.read()
  69         values["P2"] = str(pm_values.pm_ug_per_m3(2.5))
  70         values["P1"] = str(pm_values.pm_ug_per_m3(10))
  71     return values
  72
  73
  74 # Get CPU temperature to use for compensation
  75 def get_cpu_temperature():
  76     process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE, universal_newlines=True)
  77     output, _error = process.communicate()
  78     return float(output[output.index('=') + 1:output.rindex("'")])
  79
  80
  81 # Get Raspberry Pi serial number to use as ID
  82 def get_serial_number():
  83     with open('/proc/cpuinfo', 'r') as f:
  84         for line in f:
  85             if line[0:6] == 'Serial':
  86                 return line.split(":")[1].strip()
  87
  88
  89 # Check for Wi-Fi connection
  90 def check_wifi():
  91     if check_output(['hostname', '-I']):
  92         return True
  93     else:
  94         return False
  95
  96
  97 # Display Raspberry Pi serial and Wi-Fi status on LCD
  98 def display_status():
  99     wifi_status = "connected" if check_wifi() else "disconnected"
 100     text_colour = (255, 255, 255)
 101     back_colour = (0, 170, 170) if check_wifi() else (85, 15, 15)
 102     id = get_serial_number()
 103     message = "{}\nWi-Fi: {}".format(id, wifi_status)
 104     img = Image.new('RGB', (WIDTH, HEIGHT), color=(0, 0, 0))
 105     draw = ImageDraw.Draw(img)
 106     size_x, size_y = draw.textsize(message, font)
 107     x = (WIDTH - size_x) / 2
 108     y = (HEIGHT / 2) - (size_y / 2)
 109     draw.rectangle((0, 0, 160, 80), back_colour)
 110     draw.text((x, y), message, font=font, fill=text_colour)
 111     disp.display(img)
 112
 113
 114 def send_to_luftdaten(values, id):
 115     pm_values = dict(i for i in values.items() if i[0].startswith("P"))
 116     temp_values = dict(i for i in values.items() if not i[0].startswith("P"))
 117
 118     pm_values_json = [{"value_type": key, "value": val} for key, val in pm_values.items()]
 119     temp_values_json = [{"value_type": key, "value": val} for key, val in temp_values.items()]
 120
 121     resp_1 = requests.post(
 122         "https://api.luftdaten.info/v1/push-sensor-data/",
 123         json={
 124             "software_version": "enviro-plus 0.0.1",
 125             "sensordatavalues": pm_values_json
 126         },
 127         headers={
 128             "X-PIN": "1",
 129             "X-Sensor": id,
 130             "Content-Type": "application/json",
 131             "cache-control": "no-cache"
 132         }
 133     )
 134
 135     resp_2 = requests.post(
 136         "https://api.luftdaten.info/v1/push-sensor-data/",
 137         json={
 138             "software_version": "enviro-plus 0.0.1",
 139             "sensordatavalues": temp_values_json
 140         },
 141         headers={
 142             "X-PIN": "11",
 143             "X-Sensor": id,
 144             "Content-Type": "application/json",
 145             "cache-control": "no-cache"
 146         }
 147     )
 148
 149     if resp_1.ok and resp_2.ok:
 150         return True
 151     else:
 152         return False
 153
 154
 155 # Compensation factor for temperature
 156 comp_factor = 2.25
 157
 158 # Raspberry Pi ID to send to Luftdaten
 159 id = "raspi-" + get_serial_number()
 160
 161 # Width and height to calculate text position
 162 WIDTH = disp.width
 163 HEIGHT = disp.height
 164
 165 # Text settings
 166 font_size = 16
 167 font = ImageFont.truetype(UserFont, font_size)
 168
 169 # Display Raspberry Pi serial and Wi-Fi status
 170 print("Raspberry Pi serial: {}".format(get_serial_number()))
 171 print("Wi-Fi: {}\n".format("connected" if check_wifi() else "disconnected"))
 172
 173 time_since_update = 0
 174 update_time = time.time()
 175
 176 # Main loop to read data, display, and send to Luftdaten
 177 while True:
 178     try:
 179         time_since_update = time.time() - update_time
 180         values = read_values()
 181         print(values)
 182         if time_since_update > 145:
 183             resp = send_to_luftdaten(values, id)
 184             update_time = time.time()
 185             print("Response: {}\n".format("ok" if resp else "failed"))
 186         display_status()
 187     except Exception as e:
 188         print(e)