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, font_size)
  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     vmin = min(values[variable])
  71     vmax = max(values[variable])
  72     colours = [(v - vmin + 1) / (vmax - vmin + 1) for v in values[variable]]
  73     # Format the variable name and value
  74     message = "{}: {:.1f} {}".format(variable[:4], data, unit)
  75     logging.info(message)
  76     draw.rectangle((0, 0, WIDTH, HEIGHT), (255, 255, 255))
  77     for i in range(len(colours)):
  78         # Convert the values to colours from red to blue
  79         colour = (1.0 - colours[i]) * 0.6
  80         r, g, b = [int(x * 255.0) for x in colorsys.hsv_to_rgb(colour, 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))) + top_pos
  85         draw.rectangle((i, line_y, i + 1, line_y + 1), (0, 0, 0))
  86     # Write the text at the top in black
  87     draw.text((0, 0), message, font=font, fill=(0, 0, 0))
  88     st7735.display(img)
  89
  90
  91 # Get the temperature of the CPU for compensation
  92 def get_cpu_temperature():
  93     process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE, universal_newlines=True)
  94     output, _error = process.communicate()
  95     return float(output[output.index('=') + 1:output.rindex("'")])
  96
  97
  98 # Tuning factor for compensation. Decrease this number to adjust the
  99 # temperature down, and increase to adjust up
 100 factor = 2.25
 101
 102 cpu_temps = [get_cpu_temperature()] * 5
 103
 104 delay = 0.5  # Debounce the proximity tap
 105 mode = 0  # The starting mode
 106 last_page = 0
 107 light = 1
 108
 109 # Create a values dict to store the data
 110 variables = ["temperature",
 111              "pressure",
 112              "humidity",
 113              "light",
 114              "oxidised",
 115              "reduced",
 116              "nh3"]
 117
 118 values = {}
 119
 120 for v in variables:
 121     values[v] = [1] * WIDTH
 122
 123 # The main loop
 124 try:
 125     while True:
 126         proximity = ltr559.get_proximity()
 127
 128         # If the proximity crosses the threshold, toggle the mode
 129         if proximity > 1500 and time.time() - last_page > delay:
 130             mode += 1
 131             mode %= len(variables)
 132             last_page = time.time()
 133
 134         # One mode for each variable
 135         if mode == 0:
 136             # variable = "temperature"
 137             unit = "C"
 138             cpu_temp = get_cpu_temperature()
 139             # Smooth out with some averaging to decrease jitter
 140             cpu_temps = cpu_temps[1:] + [cpu_temp]
 141             avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
 142             raw_temp = bme280.get_temperature()
 143             data = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
 144             display_text(variables[mode], data, unit)
 145
 146         if mode == 1:
 147             # variable = "pressure"
 148             unit = "hPa"
 149             data = bme280.get_pressure()
 150             display_text(variables[mode], data, unit)
 151
 152         if mode == 2:
 153             # variable = "humidity"
 154             unit = "%"
 155             data = bme280.get_humidity()
 156             display_text(variables[mode], data, unit)
 157
 158         if mode == 3:
 159             # variable = "light"
 160             unit = "Lux"
 161             if proximity < 10:
 162                 data = ltr559.get_lux()
 163             else:
 164                 data = 1
 165             display_text(variables[mode], data, unit)
 166
 167         if mode == 4:
 168             # variable = "oxidised"
 169             unit = "kO"
 170             data = gas.read_all()
 171             data = data.oxidising / 1000
 172             display_text(variables[mode], data, unit)
 173
 174         if mode == 5:
 175             # variable = "reduced"
 176             unit = "kO"
 177             data = gas.read_all()
 178             data = data.reducing / 1000
 179             display_text(variables[mode], data, unit)
 180
 181         if mode == 6:
 182             # variable = "nh3"
 183             unit = "kO"
 184             data = gas.read_all()
 185             data = data.nh3 / 1000
 186             display_text(variables[mode], data, unit)
 187
 188 # Exit cleanly
 189 except KeyboardInterrupt:
 190     sys.exit(0)