from bme280 import BME280
from pms5003 import PMS5003
from enviroplus import gas
+from subprocess import PIPE, Popen
from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont
# The position of the top bar
top_pos = 25
+
# Displays data and text on the 0.96" LCD
def display_text(variable, data, unit):
# Maintain length of list
values[variable] = values[variable][1:] + [data]
# Scale the values for the variable between 0 and 1
- colours = [(v - min(values[variable]) + 1) / (max(values[variable]) - min(values[variable]) + 1) for v in values[variable]]
+ colours = [(v - min(values[variable]) + 1) / (max(values[variable])
+ - min(values[variable]) + 1) for v in values[variable]]
# Format the variable name and value
message = "{}: {:.1f} {}".format(variable[:4], data, unit)
print(message)
for i in range(len(colours)):
# Convert the values to colours from red to blue
colour = (1.0 - colours[i]) * 0.6
- r, g, b = [int(x * 255.0) for x in colorsys.hsv_to_rgb(colour, 1.0, 1.0)]
+ r, g, b = [int(x * 255.0) for x in colorsys.hsv_to_rgb(colour,
+ 1.0, 1.0)]
# Draw a 1-pixel wide rectangle of colour
draw.rectangle((i, top_pos, i+1, HEIGHT), (r, g, b))
# Draw a line graph in black
- line_y = HEIGHT - (top_pos + (colours[i] * (HEIGHT - top_pos))) + top_pos
+ line_y = HEIGHT - (top_pos + (colours[i] * (HEIGHT - top_pos)))\
+ + top_pos
draw.rectangle((i, line_y, i+1, line_y+1), (0, 0, 0))
# Write the text at the top in black
draw.text((0, 0), message, font=font, fill=(0, 0, 0))
st7735.display(img)
+
+# Get the temperature of the CPU for compensation
+def get_cpu_temperature():
+ process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE)
+ output, _error = process.communicate()
+ return float(output[output.index('=') + 1:output.rindex("'")])
+
+
+# Tuning factor for compensation. Decrease this number to adjust the
+# temperature down, and increase to adjust up
+factor = 0.8
+
+cpu_temps = [0] * 5
+
delay = 0.5 # Debounce the proximity tap
mode = 0 # The starting mode
last_page = 0
if mode == 0:
variable = "temperature"
unit = "C"
- data = bme280.get_temperature()
+ cpu_temp = get_cpu_temperature()
+ # Smooth out with some averaging to decrease jitter
+ cpu_temps = cpu_temps[1:] + [cpu_temp]
+ avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
+ raw_temp = bme280.get_temperature()
+ data = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
display_text(variable, data, unit)
if mode == 1:
if mode == 9:
variable = "pm10"
- unit = "g/m3"
+ unit = "ug/m3"
data = pms5003.read()
data = data.pm_ug_per_m3(10)
display_text(variable, data, unit)