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 import logging
  17
  18 logging.basicConfig(
  19     format='%(asctime)s.%(msecs)03d %(levelname)-8s %(message)s',
  20     level=logging.INFO,
  21     datefmt='%Y-%m-%d %H:%M:%S')
  22
  23 logging.info("""all-in-one.py - Displays readings from all of Enviro plus' sensors
  24 Press Ctrl+C to exit!
  25 """)
  26
  27 # BME280 temperature/pressure/humidity sensor
  28 bme280 = BME280()
  29
  30 # Create ST7735 LCD display class
  31 st7735 = ST7735.ST7735(
  32     port=0,
  33     cs=1,
  34     dc=9,
  35     backlight=12,
  36     rotation=270,
  37     spi_speed_hz=10000000
  38 )
  39
  40 # Initialize display
  41 st7735.begin()
  42
  43 WIDTH = st7735.width
  44 HEIGHT = st7735.height
  45
  46 # Set up canvas and font
  47 img = Image.new('RGB', (WIDTH, HEIGHT), color=(0, 0, 0))
  48 draw = ImageDraw.Draw(img)
  49 path = os.path.dirname(os.path.realpath(__file__))
  50 font = ImageFont.truetype(path + "/fonts/Asap/Asap-Bold.ttf", 20)
  51
  52 message = ""
  53
  54 # The position of the top bar
  55 top_pos = 25
  56
  57
  58 # Displays data and text on the 0.96" LCD
  59 def display_text(variable, data, unit):
  60     # Maintain length of list
  61     values[variable] = values[variable][1:] + [data]
  62     # Scale the values for the variable between 0 and 1
  63     colours = [(v - min(values[variable]) + 1) / (max(values[variable])
  64                - min(values[variable]) + 1) for v in values[variable]]
  65     # Format the variable name and value
  66     message = "{}: {:.1f} {}".format(variable[:4], data, unit)
  67     logging.info(message)
  68     draw.rectangle((0, 0, WIDTH, HEIGHT), (255, 255, 255))
  69     for i in range(len(colours)):
  70         # Convert the values to colours from red to blue
  71         colour = (1.0 - colours[i]) * 0.6
  72         r, g, b = [int(x * 255.0) for x in colorsys.hsv_to_rgb(colour,
  73                    1.0, 1.0)]
  74         # Draw a 1-pixel wide rectangle of colour
  75         draw.rectangle((i, top_pos, i+1, HEIGHT), (r, g, b))
  76         # Draw a line graph in black
  77         line_y = HEIGHT - (top_pos + (colours[i] * (HEIGHT - top_pos)))\
  78                  + top_pos
  79         draw.rectangle((i, line_y, i+1, line_y+1), (0, 0, 0))
  80     # Write the text at the top in black
  81     draw.text((0, 0), message, font=font, fill=(0, 0, 0))
  82     st7735.display(img)
  83
  84
  85 # Get the temperature of the CPU for compensation
  86 def get_cpu_temperature():
  87     process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE, universal_newlines=True)
  88     output, _error = process.communicate()
  89     return float(output[output.index('=') + 1:output.rindex("'")])
  90
  91
  92 # Tuning factor for compensation. Decrease this number to adjust the
  93 # temperature down, and increase to adjust up
  94 factor = 0.8
  95
  96 cpu_temps = [get_cpu_temperature()] * 5
  97
  98 delay = 0.5  # Debounce the proximity tap
  99 mode = 0  # The starting mode
 100 last_page = 0
 101 light = 1
 102
 103 # Create a values dict to store the data
 104 variables = ["temperature",
 105              "pressure",
 106              "humidity",
 107              "light",
 108              "oxidised",
 109              "reduced",
 110              "nh3"]
 111
 112 values = {}
 113
 114 for v in variables:
 115     values[v] = [1] * WIDTH
 116
 117 # The main loop
 118 try:
 119     while True:
 120         proximity = ltr559.get_proximity()
 121
 122         # If the proximity crosses the threshold, toggle the mode
 123         if proximity > 1500 and time.time() - last_page > delay:
 124             mode += 1
 125             mode %= len(variables)
 126             last_page = time.time()
 127
 128         # One mode for each variable
 129         if mode == 0:
 130             # variable = "temperature"
 131             unit = "C"
 132             cpu_temp = get_cpu_temperature()
 133             # Smooth out with some averaging to decrease jitter
 134             cpu_temps = cpu_temps[1:] + [cpu_temp]
 135             avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
 136             raw_temp = bme280.get_temperature()
 137             data = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
 138             display_text(variables[mode], data, unit)
 139
 140         if mode == 1:
 141             # variable = "pressure"
 142             unit = "hPa"
 143             data = bme280.get_pressure()
 144             display_text(variables[mode], data, unit)
 145
 146         if mode == 2:
 147             # variable = "humidity"
 148             unit = "%"
 149             data = bme280.get_humidity()
 150             display_text(variables[mode], data, unit)
 151
 152         if mode == 3:
 153             # variable = "light"
 154             unit = "Lux"
 155             if proximity < 10:
 156                 data = ltr559.get_lux()
 157             else:
 158                 data = 1
 159             display_text(variables[mode], data, unit)
 160
 161         if mode == 4:
 162             # variable = "oxidised"
 163             unit = "kO"
 164             data = gas.read_all()
 165             data = data.oxidising / 1000
 166             display_text(variables[mode], data, unit)
 167
 168         if mode == 5:
 169             # variable = "reduced"
 170             unit = "kO"
 171             data = gas.read_all()
 172             data = data.reducing / 1000
 173             display_text(variables[mode], data, unit)
 174
 175         if mode == 6:
 176             # variable = "nh3"
 177             unit = "kO"
 178             data = gas.read_all()
 179             data = data.nh3 / 1000
 180             display_text(variables[mode], data, unit)
 181
 182 # Exit cleanly
 183 except KeyboardInterrupt:
 184     sys.exit(0)