examples/all-in-one-no-pm.py

   1 #!/usr/bin/env python
   2
   3 import time
   4 import colorsys
   5 import os
   6 import sys
   7 import ST7735
   8 import ltr559
   9
  10 from bme280 import BME280
  11 from enviroplus import gas
  12 from subprocess import PIPE, Popen
  13 from PIL import Image
  14 from PIL import ImageDraw
  15 from PIL import ImageFont
  16
  17 print("""all-in-one.py - Displays readings from all of Enviro plus' sensors
  18 Press Ctrl+C to exit!
  19 """)
  20
  21 # BME280 temperature/pressure/humidity sensor
  22 bme280 = BME280()
  23
  24 # Create ST7735 LCD display class
  25 st7735 = ST7735.ST7735(
  26     port=0,
  27     cs=1,
  28     dc=9,
  29     backlight=12,
  30     rotation=270,
  31     spi_speed_hz=10000000
  32 )
  33
  34 # Initialize display
  35 st7735.begin()
  36
  37 WIDTH = st7735.width
  38 HEIGHT = st7735.height
  39
  40 # Set up canvas and font
  41 img = Image.new('RGB', (WIDTH, HEIGHT), color=(0, 0, 0))
  42 draw = ImageDraw.Draw(img)
  43 path = os.path.dirname(os.path.realpath(__file__))
  44 font = ImageFont.truetype(path + "/fonts/Asap/Asap-Bold.ttf", 20)
  45
  46 message = ""
  47
  48 # The position of the top bar
  49 top_pos = 25
  50
  51
  52 # Displays data and text on the 0.96" LCD
  53 def display_text(variable, data, unit):
  54     # Maintain length of list
  55     values[variable] = values[variable][1:] + [data]
  56     # Scale the values for the variable between 0 and 1
  57     colours = [(v - min(values[variable]) + 1) / (max(values[variable])
  58                - min(values[variable]) + 1) for v in values[variable]]
  59     # Format the variable name and value
  60     message = "{}: {:.1f} {}".format(variable[:4], data, unit)
  61     print(message)
  62     draw.rectangle((0, 0, WIDTH, HEIGHT), (255, 255, 255))
  63     for i in range(len(colours)):
  64         # Convert the values to colours from red to blue
  65         colour = (1.0 - colours[i]) * 0.6
  66         r, g, b = [int(x * 255.0) for x in colorsys.hsv_to_rgb(colour,
  67                    1.0, 1.0)]
  68         # Draw a 1-pixel wide rectangle of colour
  69         draw.rectangle((i, top_pos, i+1, HEIGHT), (r, g, b))
  70         # Draw a line graph in black
  71         line_y = HEIGHT - (top_pos + (colours[i] * (HEIGHT - top_pos)))\
  72                  + top_pos
  73         draw.rectangle((i, line_y, i+1, line_y+1), (0, 0, 0))
  74     # Write the text at the top in black
  75     draw.text((0, 0), message, font=font, fill=(0, 0, 0))
  76     st7735.display(img)
  77
  78
  79 # Get the temperature of the CPU for compensation
  80 def get_cpu_temperature():
  81     process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE, universal_newlines=True)
  82     output, _error = process.communicate()
  83     output = output.decode()
  84     return float(output[output.index('=') + 1:output.rindex("'")])
  85
  86
  87 # Tuning factor for compensation. Decrease this number to adjust the
  88 # temperature down, and increase to adjust up
  89 factor = 0.8
  90
  91 cpu_temps = [0] * 5
  92
  93 delay = 0.5  # Debounce the proximity tap
  94 mode = 0  # The starting mode
  95 last_page = 0
  96 light = 1
  97
  98 # Create a values dict to store the data
  99 variables = ["temperature",
 100              "pressure",
 101              "humidity",
 102              "light",
 103              "oxidised",
 104              "reduced",
 105              "nh3"]
 106
 107 values = {}
 108
 109 for v in variables:
 110     values[v] = [1] * WIDTH
 111
 112 # The main loop
 113 try:
 114     while True:
 115         proximity = ltr559.get_proximity()
 116
 117         # If the proximity crosses the threshold, toggle the mode
 118         if proximity > 1500 and time.time() - last_page > delay:
 119             mode += 1
 120             mode %= len(variables)
 121             last_page = time.time()
 122
 123         # One mode for each variable
 124         if mode == 0:
 125             variable = "temperature"
 126             unit = "C"
 127             cpu_temp = get_cpu_temperature()
 128             # Smooth out with some averaging to decrease jitter
 129             cpu_temps = cpu_temps[1:] + [cpu_temp]
 130             avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
 131             raw_temp = bme280.get_temperature()
 132             data = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
 133             display_text(variable, data, unit)
 134
 135         if mode == 1:
 136             variable = "pressure"
 137             unit = "hPa"
 138             data = bme280.get_pressure()
 139             display_text(variable, data, unit)
 140
 141         if mode == 2:
 142             variable = "humidity"
 143             unit = "%"
 144             data = bme280.get_humidity()
 145             display_text(variable, data, unit)
 146
 147         if mode == 3:
 148             variable = "light"
 149             unit = "Lux"
 150             if proximity < 10:
 151                 data = ltr559.get_lux()
 152             else:
 153                 data = 1
 154             display_text(variable, data, unit)
 155
 156         if mode == 4:
 157             variable = "oxidised"
 158             unit = "kO"
 159             data = gas.read_all()
 160             data = data.oxidising / 1000
 161             display_text(variable, data, unit)
 162
 163         if mode == 5:
 164             variable = "reduced"
 165             unit = "kO"
 166             data = gas.read_all()
 167             data = data.reducing / 1000
 168             display_text(variable, data, unit)
 169
 170         if mode == 6:
 171             variable = "nh3"
 172             unit = "kO"
 173             data = gas.read_all()
 174             data = data.nh3 / 1000
 175             display_text(variable, data, unit)
 176
 177 # Exit cleanly
 178 except KeyboardInterrupt:
 179     sys.exit(0)