examples/all-in-one-enviro-mini.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
 115 values = {}
 116
 117 for v in variables:
 118     values[v] = [1] * WIDTH
 119
 120 # The main loop
 121 try:
 122     while True:
 123         proximity = ltr559.get_proximity()
 124
 125         # If the proximity crosses the threshold, toggle the mode
 126         if proximity > 1500 and time.time() - last_page > delay:
 127             mode += 1
 128             mode %= len(variables)
 129             last_page = time.time()
 130
 131         # One mode for each variable
 132         if mode == 0:
 133             # variable = "temperature"
 134             unit = "C"
 135             cpu_temp = get_cpu_temperature()
 136             # Smooth out with some averaging to decrease jitter
 137             cpu_temps = cpu_temps[1:] + [cpu_temp]
 138             avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
 139             raw_temp = bme280.get_temperature()
 140             data = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
 141             display_text(variables[mode], data, unit)
 142
 143         if mode == 1:
 144             # variable = "pressure"
 145             unit = "hPa"
 146             data = bme280.get_pressure()
 147             display_text(variables[mode], data, unit)
 148
 149         if mode == 2:
 150             # variable = "humidity"
 151             unit = "%"
 152             data = bme280.get_humidity()
 153             display_text(variables[mode], data, unit)
 154
 155         if mode == 3:
 156             # variable = "light"
 157             unit = "Lux"
 158             if proximity < 10:
 159                 data = ltr559.get_lux()
 160             else:
 161                 data = 1
 162             display_text(variables[mode], data, unit)
 163
 164 # Exit cleanly
 165 except KeyboardInterrupt:
 166     sys.exit(0)