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 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 import logging
  22
  23 logging.basicConfig(
  24     format='%(asctime)s.%(msecs)03d %(levelname)-8s %(message)s',
  25     level=logging.INFO,
  26     datefmt='%Y-%m-%d %H:%M:%S')
  27
  28 logging.info("""all-in-one.py - Displays readings from all of Enviro plus' sensors
  29 Press Ctrl+C to exit!
  30 """)
  31
  32 # BME280 temperature/pressure/humidity sensor
  33 bme280 = BME280()
  34
  35 # Create ST7735 LCD display class
  36 st7735 = ST7735.ST7735(
  37     port=0,
  38     cs=1,
  39     dc=9,
  40     backlight=12,
  41     rotation=270,
  42     spi_speed_hz=10000000
  43 )
  44
  45 # Initialize display
  46 st7735.begin()
  47
  48 WIDTH = st7735.width
  49 HEIGHT = st7735.height
  50
  51 # Set up canvas and font
  52 img = Image.new('RGB', (WIDTH, HEIGHT), color=(0, 0, 0))
  53 draw = ImageDraw.Draw(img)
  54 path = os.path.dirname(os.path.realpath(__file__))
  55 font = ImageFont.truetype(path + "/fonts/Asap/Asap-Bold.ttf", 20)
  56
  57 message = ""
  58
  59 # The position of the top bar
  60 top_pos = 25
  61
  62
  63 # Displays data and text on the 0.96" LCD
  64 def display_text(variable, data, unit):
  65     # Maintain length of list
  66     values[variable] = values[variable][1:] + [data]
  67     # Scale the values for the variable between 0 and 1
  68     colours = [(v - min(values[variable]) + 1) / (max(values[variable])
  69                - min(values[variable]) + 1) for v in values[variable]]
  70     # Format the variable name and value
  71     message = "{}: {:.1f} {}".format(variable[:4], data, unit)
  72     logging.info(message)
  73     draw.rectangle((0, 0, WIDTH, HEIGHT), (255, 255, 255))
  74     for i in range(len(colours)):
  75         # Convert the values to colours from red to blue
  76         colour = (1.0 - colours[i]) * 0.6
  77         r, g, b = [int(x * 255.0) for x in colorsys.hsv_to_rgb(colour,
  78                    1.0, 1.0)]
  79         # Draw a 1-pixel wide rectangle of colour
  80         draw.rectangle((i, top_pos, i+1, HEIGHT), (r, g, b))
  81         # Draw a line graph in black
  82         line_y = HEIGHT - (top_pos + (colours[i] * (HEIGHT - top_pos)))\
  83                  + top_pos
  84         draw.rectangle((i, line_y, i+1, line_y+1), (0, 0, 0))
  85     # Write the text at the top in black
  86     draw.text((0, 0), message, font=font, fill=(0, 0, 0))
  87     st7735.display(img)
  88
  89
  90 # Get the temperature of the CPU for compensation
  91 def get_cpu_temperature():
  92     process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE, universal_newlines=True)
  93     output, _error = process.communicate()
  94     return float(output[output.index('=') + 1:output.rindex("'")])
  95
  96
  97 # Tuning factor for compensation. Decrease this number to adjust the
  98 # temperature down, and increase to adjust up
  99 factor = 0.8
 100
 101 cpu_temps = [get_cpu_temperature()] * 5
 102
 103 delay = 0.5  # Debounce the proximity tap
 104 mode = 0  # The starting mode
 105 last_page = 0
 106 light = 1
 107
 108 # Create a values dict to store the data
 109 variables = ["temperature",
 110              "pressure",
 111              "humidity",
 112              "light",
 113              "oxidised",
 114              "reduced",
 115              "nh3"]
 116
 117 values = {}
 118
 119 for v in variables:
 120     values[v] = [1] * WIDTH
 121
 122 # The main loop
 123 try:
 124     while True:
 125         proximity = ltr559.get_proximity()
 126
 127         # If the proximity crosses the threshold, toggle the mode
 128         if proximity > 1500 and time.time() - last_page > delay:
 129             mode += 1
 130             mode %= len(variables)
 131             last_page = time.time()
 132
 133         # One mode for each variable
 134         if mode == 0:
 135             # variable = "temperature"
 136             unit = "C"
 137             cpu_temp = get_cpu_temperature()
 138             # Smooth out with some averaging to decrease jitter
 139             cpu_temps = cpu_temps[1:] + [cpu_temp]
 140             avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
 141             raw_temp = bme280.get_temperature()
 142             data = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
 143             display_text(variables[mode], data, unit)
 144
 145         if mode == 1:
 146             # variable = "pressure"
 147             unit = "hPa"
 148             data = bme280.get_pressure()
 149             display_text(variables[mode], data, unit)
 150
 151         if mode == 2:
 152             # variable = "humidity"
 153             unit = "%"
 154             data = bme280.get_humidity()
 155             display_text(variables[mode], data, unit)
 156
 157         if mode == 3:
 158             # variable = "light"
 159             unit = "Lux"
 160             if proximity < 10:
 161                 data = ltr559.get_lux()
 162             else:
 163                 data = 1
 164             display_text(variables[mode], data, unit)
 165
 166         if mode == 4:
 167             # variable = "oxidised"
 168             unit = "kO"
 169             data = gas.read_all()
 170             data = data.oxidising / 1000
 171             display_text(variables[mode], data, unit)
 172
 173         if mode == 5:
 174             # variable = "reduced"
 175             unit = "kO"
 176             data = gas.read_all()
 177             data = data.reducing / 1000
 178             display_text(variables[mode], data, unit)
 179
 180         if mode == 6:
 181             # variable = "nh3"
 182             unit = "kO"
 183             data = gas.read_all()
 184             data = data.nh3 / 1000
 185             display_text(variables[mode], data, unit)
 186
 187 # Exit cleanly
 188 except KeyboardInterrupt:
 189     sys.exit(0)