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     return float(output[output.index('=') + 1:output.rindex("'")])
  84
  85
  86 # Tuning factor for compensation. Decrease this number to adjust the
  87 # temperature down, and increase to adjust up
  88 factor = 0.8
  89
  90 cpu_temps = [get_cpu_temperature()] * 5
  91
  92 delay = 0.5  # Debounce the proximity tap
  93 mode = 0  # The starting mode
  94 last_page = 0
  95 light = 1
  96
  97 # Create a values dict to store the data
  98 variables = ["temperature",
  99              "pressure",
 100              "humidity",
 101              "light",
 102              "oxidised",
 103              "reduced",
 104              "nh3"]
 105
 106 values = {}
 107
 108 for v in variables:
 109     values[v] = [1] * WIDTH
 110
 111 # The main loop
 112 try:
 113     while True:
 114         proximity = ltr559.get_proximity()
 115
 116         # If the proximity crosses the threshold, toggle the mode
 117         if proximity > 1500 and time.time() - last_page > delay:
 118             mode += 1
 119             mode %= len(variables)
 120             last_page = time.time()
 121
 122         # One mode for each variable
 123         if mode == 0:
 124             variable = "temperature"
 125             unit = "C"
 126             cpu_temp = get_cpu_temperature()
 127             # Smooth out with some averaging to decrease jitter
 128             cpu_temps = cpu_temps[1:] + [cpu_temp]
 129             avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
 130             raw_temp = bme280.get_temperature()
 131             data = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
 132             display_text(variable, data, unit)
 133
 134         if mode == 1:
 135             variable = "pressure"
 136             unit = "hPa"
 137             data = bme280.get_pressure()
 138             display_text(variable, data, unit)
 139
 140         if mode == 2:
 141             variable = "humidity"
 142             unit = "%"
 143             data = bme280.get_humidity()
 144             display_text(variable, data, unit)
 145
 146         if mode == 3:
 147             variable = "light"
 148             unit = "Lux"
 149             if proximity < 10:
 150                 data = ltr559.get_lux()
 151             else:
 152                 data = 1
 153             display_text(variable, data, unit)
 154
 155         if mode == 4:
 156             variable = "oxidised"
 157             unit = "kO"
 158             data = gas.read_all()
 159             data = data.oxidising / 1000
 160             display_text(variable, data, unit)
 161
 162         if mode == 5:
 163             variable = "reduced"
 164             unit = "kO"
 165             data = gas.read_all()
 166             data = data.reducing / 1000
 167             display_text(variable, data, unit)
 168
 169         if mode == 6:
 170             variable = "nh3"
 171             unit = "kO"
 172             data = gas.read_all()
 173             data = data.nh3 / 1000
 174             display_text(variable, data, unit)
 175
 176 # Exit cleanly
 177 except KeyboardInterrupt:
 178     sys.exit(0)