def get_readings(sensor):
# The sense HAT does not include any way to obtain an air quality score via gas measurement,
# so we can create one using the temperature and humidity reading based on distance from ideal values
max_iaq = 500
min_iaq = 25
temperature_ideal = 25
temperature_worst_variance = 40
humidity_ideal = 40
humidity_worst_variance = 40
humidity_weighting = 0.25 # this means % of the AQ figure will be humidity, the rest will be temperature
# Get the current temperature and humidity readings
current_temperature = sensor.get_temperature()
current_humidity = sensor.get_humidity()
# Find out how far from the ideal the current values are
current_temperature_variance = abs(current_temperature - temperature_ideal)/temperature_worst_variance
# if the variance is greater than 1 (100%), set it to as a maximum
# note also that 100% here is the worst possible value
if current_temperature_variance > 1:
current_temperature_variance = 1
# Do the same thing for the humidity reading
current_humidity_variance = abs(current_humidity - humidity_ideal)/humidity_worst_variance
if current_humidity_variance > 1:
current_humidity_variance = 1
# Scale the current variance measurements in accordance with the weighting to calculate a percentage
# this gives us a score where 1 is the worst possible value
air_quality_score = (current_humidity_variance * humidity_weighting) + (current_temperature_variance * (1 - humidity_weighting))
air_quality_score = air_quality_score * 500
# As we have a sense HAT we can give an indication of the air quality on the LED matrix
from ledmatrix import LedMatrix
display = LedMatrix()
display.clear()
if air_quality_score < 100:
# Happy face!
face_color = [0, 255, 0]
face_pixels = [
0, 0, 1, 1, 1, 1, 0, 0,
0, 1, 0, 0, 0, 0, 1, 0,
1, 0, 1, 0, 0, 1, 0, 1,
1, 0, 0, 0, 0, 0, 0, 1,
1, 0, 1, 0, 0, 1, 0, 1,
1, 0, 0, 1, 1, 0, 0, 1,
0, 1, 0, 0, 0, 0, 1, 0,
0, 0, 1, 1, 1, 1, 0, 0
]
elif air_quality_score < 250:
# Neutral face
face_color = [250, 255, 0]
face_pixels = [
0, 0, 1, 1, 1, 1, 0, 0,
0, 1, 0, 0, 0, 0, 1, 0,
1, 0, 1, 0, 0, 1, 0, 1,
1, 0, 0, 0, 0, 0, 0, 1,
1, 0, 1, 1, 1, 1, 0, 1,
1, 0, 0, 0, 0, 0, 0, 1,
0, 1, 0, 0, 0, 0, 1, 0,
0, 0, 1, 1, 1, 1, 0, 0
]
else:
# Sad face
face_color = [255, 0, 0]
face_pixels = [
0, 0, 1, 1, 1, 1, 0, 0,
0, 1, 0, 0, 0, 0, 1, 0,
1, 0, 1, 0, 0, 1, 0, 1,
1, 0, 0, 0, 0, 0, 0, 1,
1, 0, 0, 1, 1, 0, 0, 1,
1, 0, 1, 0, 0, 1, 0, 1,
0, 1, 0, 0, 0, 0, 1, 0,
0, 0, 1, 1, 1, 1, 0, 0
]
for x in range(64):
if face_pixels[x] == 1:
face_pixels[x] = face_color
elif face_pixels[x] == 0:
face_pixels[x] = [0,0,0]
display.set_pixels(face_pixels)
return [
{
'measurement': 'balena-sense',
'fields': {
'temperature': float(current_temperature),
'pressure': float(sensor.environ.pressure),
'humidity': float(current_humidity),
'air_quality_score': float(air_quality_score)
}
}
]
time.sleep(0.2)
if wlan.isconnected():
break
if wlan.isconnected():
break
scene.render(0, 0, 0)
if not wlan.isconnected():
# TODO: This will only use SSID/auth settings from NVRAM during cold boots
print('WLAN: No known networks, enabling AP with ssid={}, pwd={}'.
format(default_ssid, default_auth[1]))
wlan.init(mode=WLAN.AP,
ssid=default_ssid,
auth=default_auth,
channel=6)
else:
display.clear()
print('WLAN: Connected with IP: {}'.format(wlan.ifconfig()[0]))
# Initialize RTC now that we're connected
driver.set_rtc(scene)
scene.render(0, 0, 0)
scene = None
del BootScene
elif esp8266_board:
pass
# This is where it all begins
r = RenderLoop(display, config)
if 'Clock' in config:
from clockscene import ClockScene
scene = ClockScene(display, config['Clock'])