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

   1 #!/usr/bin/env python3
   2
   3 import time
   4 import colorsys
   5 import os
   6 import sys
   7 import ST7735
   8 try:
   9     # Transitional fix for breaking change in LTR559
  10     from ltr559 import LTR559
  11     ltr559 = LTR559()
  12 except ImportError:
  13     import ltr559
  14
  15 from bme280 import BME280
  16 from enviroplus import gas
  17 from subprocess import PIPE, Popen
  18 from PIL import Image
  19 from PIL import ImageDraw
  20 from PIL import ImageFont
  21 from fonts.ttf import RobotoMedium as UserFont
  22 import logging
  23
  24 logging.basicConfig(
  25     format='%(asctime)s.%(msecs)03d %(levelname)-8s %(message)s',
  26     level=logging.INFO,
  27     datefmt='%Y-%m-%d %H:%M:%S')
  28
  29 logging.info("""all-in-one.py - Displays readings from all of Enviro plus' sensors
  30 Press Ctrl+C to exit!
  31 """)
  32
  33 # BME280 temperature/pressure/humidity sensor
  34 bme280 = BME280()
  35
  36 # Create ST7735 LCD display class
  37 st7735 = 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 st7735.begin()
  48
  49 WIDTH = st7735.width
  50 HEIGHT = st7735.height
  51
  52 # Set up canvas and font
  53 img = Image.new('RGB', (WIDTH, HEIGHT), color=(0, 0, 0))
  54 draw = ImageDraw.Draw(img)
  55 path = os.path.dirname(os.path.realpath(__file__))
  56 font_size = 20
  57 font = ImageFont.truetype(UserFont, FontSize)
  58
  59 message = ""
  60
  61 # The position of the top bar
  62 top_pos = 25
  63
  64
  65 # Displays data and text on the 0.96" LCD
  66 def display_text(variable, data, unit):
  67     # Maintain length of list
  68     values[variable] = values[variable][1:] + [data]
  69     # Scale the values for the variable between 0 and 1
  70     colours = [(v - min(values[variable]) + 1) / (max(values[variable])
  71                - min(values[variable]) + 1) for v in values[variable]]
  72     # Format the variable name and value
  73     message = "{}: {:.1f} {}".format(variable[:4], data, unit)
  74     logging.info(message)
  75     draw.rectangle((0, 0, WIDTH, HEIGHT), (255, 255, 255))
  76     for i in range(len(colours)):
  77         # Convert the values to colours from red to blue
  78         colour = (1.0 - colours[i]) * 0.6
  79         r, g, b = [int(x * 255.0) for x in colorsys.hsv_to_rgb(colour,
  80                    1.0, 1.0)]
  81         # Draw a 1-pixel wide rectangle of colour
  82         draw.rectangle((i, top_pos, i+1, HEIGHT), (r, g, b))
  83         # Draw a line graph in black
  84         line_y = HEIGHT - (top_pos + (colours[i] * (HEIGHT - top_pos)))\
  85                  + top_pos
  86         draw.rectangle((i, line_y, i+1, line_y+1), (0, 0, 0))
  87     # Write the text at the top in black
  88     draw.text((0, 0), message, font=font, fill=(0, 0, 0))
  89     st7735.display(img)
  90
  91
  92 # Get the temperature of the CPU for compensation
  93 def get_cpu_temperature():
  94     process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE, universal_newlines=True)
  95     output, _error = process.communicate()
  96     return float(output[output.index('=') + 1:output.rindex("'")])
  97
  98
  99 # Tuning factor for compensation. Decrease this number to adjust the
 100 # temperature down, and increase to adjust up
 101 factor = 2.25
 102
 103 cpu_temps = [get_cpu_temperature()] * 5
 104
 105 delay = 0.5  # Debounce the proximity tap
 106 mode = 0  # The starting mode
 107 last_page = 0
 108 light = 1
 109
 110 # Create a values dict to store the data
 111 variables = ["temperature",
 112              "pressure",
 113              "humidity",
 114              "light",
 115              "oxidised",
 116              "reduced",
 117              "nh3"]
 118
 119 values = {}
 120
 121 for v in variables:
 122     values[v] = [1] * WIDTH
 123
 124 # The main loop
 125 try:
 126     while True:
 127         proximity = ltr559.get_proximity()
 128
 129         # If the proximity crosses the threshold, toggle the mode
 130         if proximity > 1500 and time.time() - last_page > delay:
 131             mode += 1
 132             mode %= len(variables)
 133             last_page = time.time()
 134
 135         # One mode for each variable
 136         if mode == 0:
 137             # variable = "temperature"
 138             unit = "C"
 139             cpu_temp = get_cpu_temperature()
 140             # Smooth out with some averaging to decrease jitter
 141             cpu_temps = cpu_temps[1:] + [cpu_temp]
 142             avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
 143             raw_temp = bme280.get_temperature()
 144             data = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
 145             display_text(variables[mode], data, unit)
 146
 147         if mode == 1:
 148             # variable = "pressure"
 149             unit = "hPa"
 150             data = bme280.get_pressure()
 151             display_text(variables[mode], data, unit)
 152
 153         if mode == 2:
 154             # variable = "humidity"
 155             unit = "%"
 156             data = bme280.get_humidity()
 157             display_text(variables[mode], data, unit)
 158
 159         if mode == 3:
 160             # variable = "light"
 161             unit = "Lux"
 162             if proximity < 10:
 163                 data = ltr559.get_lux()
 164             else:
 165                 data = 1
 166             display_text(variables[mode], data, unit)
 167
 168         if mode == 4:
 169             # variable = "oxidised"
 170             unit = "kO"
 171             data = gas.read_all()
 172             data = data.oxidising / 1000
 173             display_text(variables[mode], data, unit)
 174
 175         if mode == 5:
 176             # variable = "reduced"
 177             unit = "kO"
 178             data = gas.read_all()
 179             data = data.reducing / 1000
 180             display_text(variables[mode], data, unit)
 181
 182         if mode == 6:
 183             # variable = "nh3"
 184             unit = "kO"
 185             data = gas.read_all()
 186             data = data.nh3 / 1000
 187             display_text(variables[mode], data, unit)
 188
 189 # Exit cleanly
 190 except KeyboardInterrupt:
 191     sys.exit(0)