examples/luftdaten.py

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