examples/luftdaten.py

   1 #!/usr/bin/env python
   2
   3 import requests
   4 import ST7735
   5 from bme280 import BME280
   6 from pms5003 import PMS5003, ReadTimeoutError
   7 from subprocess import PIPE, Popen, check_output
   8 from PIL import Image, ImageDraw, ImageFont
   9
  10 try:
  11     from smbus2 import SMBus
  12 except ImportError:
  13     from smbus import SMBus
  14
  15 import logging
  16
  17 logging.basicConfig(
  18     format='%(asctime)s.%(msecs)03d %(levelname)-8s %(message)s',
  19     level=logging.INFO,
  20     datefmt='%Y-%m-%d %H:%M:%S')
  21
  22 logging.info("""luftdaten.py - Reads temperature, pressure, humidity,
  23 PM2.5, and PM10 from Enviro plus and sends data to Luftdaten,
  24 the citizen science air quality project.
  25
  26 Note: you'll need to register with Luftdaten at:
  27 https://meine.luftdaten.info/ and enter your Raspberry Pi
  28 serial number that's displayed on the Enviro plus LCD along
  29 with the other details before the data appears on the
  30 Luftdaten map.
  31
  32 Press Ctrl+C to exit!
  33
  34 """)
  35
  36 bus = SMBus(1)
  37
  38 # Create BME280 instance
  39 bme280 = BME280(i2c_dev=bus)
  40
  41 # Create LCD instance
  42 disp = ST7735.ST7735(
  43     port=0,
  44     cs=1,
  45     dc=9,
  46     backlight=12,
  47     rotation=270,
  48     spi_speed_hz=10000000
  49 )
  50
  51 # Initialize display
  52 disp.begin()
  53
  54 # Create PMS5003 instance
  55 pms5003 = PMS5003()
  56
  57
  58 # Read values from BME280 and PMS5003 and return as dict
  59 def read_values():
  60     values = {}
  61     cpu_temp = get_cpu_temperature()
  62     raw_temp = bme280.get_temperature()
  63     comp_temp = raw_temp - ((cpu_temp - raw_temp) / comp_factor)
  64     values["temperature"] = "{:.2f}".format(comp_temp)
  65     values["pressure"] = "{:.2f}".format(bme280.get_pressure() * 100)
  66     values["humidity"] = "{:.2f}".format(bme280.get_humidity())
  67     try:
  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     except ReadTimeoutError:
  72         pms5003.reset()
  73         pm_values = pms5003.read()
  74         values["P2"] = str(pm_values.pm_ug_per_m3(2.5))
  75         values["P1"] = str(pm_values.pm_ug_per_m3(10))
  76     return values
  77
  78
  79 # Get CPU temperature to use for compensation
  80 def get_cpu_temperature():
  81     process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE, universal_newlines=True)
  82     output, _error = process.communicate()
  83     return float(output[output.index('=') + 1:output.rindex("'")])
  84
  85
  86 # Get Raspberry Pi serial number to use as ID
  87 def get_serial_number():
  88     with open('/proc/cpuinfo', 'r') as f:
  89         for line in f:
  90             if line[0:6] == 'Serial':
  91                 return line.split(":")[1].strip()
  92
  93
  94 # Check for Wi-Fi connection
  95 def check_wifi():
  96     if check_output(['hostname', '-I']):
  97         return True
  98     else:
  99         return False
 100
 101
 102 # Display Raspberry Pi serial and Wi-Fi status on LCD
 103 def display_status():
 104     wifi_status = "connected" if check_wifi() else "disconnected"
 105     text_colour = (255, 255, 255)
 106     back_colour = (0, 170, 170) if check_wifi() else (85, 15, 15)
 107     id = get_serial_number()
 108     message = "{}\nWi-Fi: {}".format(id, wifi_status)
 109     img = Image.new('RGB', (WIDTH, HEIGHT), color=(0, 0, 0))
 110     draw = ImageDraw.Draw(img)
 111     size_x, size_y = draw.textsize(message, font)
 112     x = (WIDTH - size_x) / 2
 113     y = (HEIGHT / 2) - (size_y / 2)
 114     draw.rectangle((0, 0, 160, 80), back_colour)
 115     draw.text((x, y), message, font=font, fill=text_colour)
 116     disp.display(img)
 117
 118
 119 def send_to_luftdaten(values, id):
 120     pm_values = dict(i for i in values.items() if i[0].startswith("P"))
 121     temp_values = dict(i for i in values.items() if not i[0].startswith("P"))
 122
 123     resp_1 = requests.post("https://api.luftdaten.info/v1/push-sensor-data/",
 124              json={
 125                  "software_version": "enviro-plus 0.0.1",
 126                  "sensordatavalues": [{"value_type": key, "value": val} for
 127                                       key, val in pm_values.items()]
 128              },
 129              headers={
 130                  "X-PIN":    "1",
 131                  "X-Sensor": id,
 132                  "Content-Type": "application/json",
 133                  "cache-control": "no-cache"
 134              }
 135     )
 136
 137     resp_2 = requests.post("https://api.luftdaten.info/v1/push-sensor-data/",
 138              json={
 139                  "software_version": "enviro-plus 0.0.1",
 140                  "sensordatavalues": [{"value_type": key, "value": val} for
 141                                       key, val in temp_values.items()]
 142              },
 143              headers={
 144                  "X-PIN":    "11",
 145                  "X-Sensor": id,
 146                  "Content-Type": "application/json",
 147                  "cache-control": "no-cache"
 148              }
 149     )
 150
 151     if resp_1.ok and resp_2.ok:
 152         return True
 153     else:
 154         return False
 155
 156
 157 # Compensation factor for temperature
 158 comp_factor = 1.2
 159
 160 # Raspberry Pi ID to send to Luftdaten
 161 id = "raspi-" + get_serial_number()
 162
 163 # Width and height to calculate text position
 164 WIDTH = disp.width
 165 HEIGHT = disp.height
 166
 167 # Text settings
 168 font_size = 16
 169 font = ImageFont.truetype("fonts/Asap/Asap-Bold.ttf", font_size)
 170
 171 # Display Raspberry Pi serial and Wi-Fi status
 172 logging.info("Raspberry Pi serial: {}".format(get_serial_number()))
 173 logging.info("Wi-Fi: {}\n".format("connected" if check_wifi() else "disconnected"))
 174
 175 # Main loop to read data, display, and send to Luftdaten
 176 while True:
 177     try:
 178         values = read_values()
 179         logging.info(values)
 180         resp = send_to_luftdaten(values, id)
 181         logging.info("Response: {}\n".format("ok" if resp else "failed"))
 182         display_status()
 183     except Exception as e:
 184         logging.info(e)