examples/all-in-one-enviro-mini-bk.py

   1 #!/usr/bin/env python3
   2
   3 import time
   4 import colorsys
   5 import os
   6 import sys
   7 import ST7735
   8 import schedule # https://pypi.org/project/schedule/ via https://stackoverflow.com/a/16786600
   9 import datetime # http://stackoverflow.com/questions/2150739/ddg#28147286
  10 try:
  11     # Transitional fix for breaking change in LTR559
  12     from ltr559 import LTR559
  13     ltr559 = LTR559()
  14 except ImportError:
  15     import ltr559
  16
  17 from bme280 import BME280
  18 from enviroplus import gas
  19 from subprocess import PIPE, Popen
  20 from PIL import Image
  21 from PIL import ImageDraw
  22 from PIL import ImageFont
  23 from fonts.ttf import RobotoMedium as UserFont
  24 import logging
  25 import numpy as np
  26
  27 logging.basicConfig(
  28     format='%(asctime)s.%(msecs)03d %(levelname)-8s %(message)s',
  29     level=logging.INFO,
  30     datefmt='%Y-%m-%d %H:%M:%S')
  31
  32 logging.info("""all-in-one.py - Displays readings from all of Enviro plus' sensors
  33 Press Ctrl+C to exit!
  34 """)
  35
  36 # Script Constants
  37 varLenBufferTTL = int((2*24*60*60)*10**9) # time-to-live in nanoseconds
  38
  39 # BME280 temperature/pressure/humidity sensor
  40 bme280 = BME280()
  41
  42 # Create ST7735 LCD display class
  43 st7735 = ST7735.ST7735(
  44     port=0,
  45     cs=1,
  46     dc=9,
  47     backlight=12,
  48     rotation=270,
  49     #rotation=90, # flip upside down wrt enviro+ default orientation
  50     spi_speed_hz=10000000
  51 )
  52
  53 # Initialize display
  54 st7735.begin()
  55
  56 WIDTH = st7735.width
  57 HEIGHT = st7735.height
  58
  59 # Set up canvas and font
  60 img = Image.new('RGB', (WIDTH, HEIGHT), color=(0, 0, 0))
  61 draw = ImageDraw.Draw(img)
  62 path = os.path.dirname(os.path.realpath(__file__))
  63 font_size = 20
  64 font = ImageFont.truetype(UserFont, font_size)
  65 font2_size = 15
  66 font2 = ImageFont.truetype(UserFont, font2_size)
  67
  68 message = ""
  69
  70 # The position of the top bar
  71 top_pos = 25
  72
  73
  74 # Displays data and text on the 0.96" LCD
  75 def display_text(variable, data, unit):
  76     # Maintain length of list
  77     values[variable] = values[variable][1:] + [data]
  78     # Scale the values for the variable between 0 and 1
  79     vmin = min(values[variable])
  80     vmax = max(values[variable])
  81     colours = [(v - vmin + 1) / (vmax - vmin + 1) for v in values[variable]]
  82     # Format the variable name and value
  83     message = "{}: {:.1f} {}".format(variable[:4], data, unit)
  84     logging.info(message)
  85     draw.rectangle((0, 0, WIDTH, HEIGHT), (255, 255, 255))
  86     for i in range(len(colours)):
  87         # Convert the values to colours from red to blue
  88         colour = (1.0 - colours[i]) * 0.6
  89         r, g, b = [int(x * 255.0) for x in colorsys.hsv_to_rgb(colour, 1.0, 1.0)]
  90         # Draw a 1-pixel wide rectangle of colour
  91         draw.rectangle((i, top_pos, i + 1, HEIGHT), (r, g, b))
  92         # Draw a line graph in black
  93         line_y = HEIGHT - (top_pos + (colours[i] * (HEIGHT - top_pos))) + top_pos
  94         draw.rectangle((i, line_y, i + 1, line_y + 1), (0, 0, 0))
  95     # Write the text at the top in black
  96     draw.text((0, 0), message, font=font, fill=(0, 0, 0))
  97     st7735.display(img)
  98
  99 # Displays data and text on the 0.96" LCD
 100 def display_text2(variable, data, unit, values):
 101     # Scale the values for the variable between 0 and 1
 102     #print('DEBUG:len(values[' + str(variable) + ']):' + str(len(values[variable])))
 103     #print('DEBUG:values[' + str(variable) + ']:' + str(values[variable]))
 104     vmin = min(values[variable])
 105     vmax = max(values[variable])
 106     colours = [(v - vmin + 1) / (vmax - vmin + 1) for v in values[variable]]
 107     # Format the variable name and value
 108     message = "{}: {:.1f} {}".format(variable[:4], data, unit)
 109     #message = "{}: {:.1f} {}".format(variable[:4], values[variable][-1], unit)
 110     logging.info(message)
 111     draw.rectangle((0, 0, WIDTH, HEIGHT), (255, 255, 255))
 112     for i in range(len(colours)):
 113         # Convert the values to colours from red to blue
 114         colour = (1.0 - colours[i]) * 0.6
 115         r, g, b = [int(x * 255.0) for x in colorsys.hsv_to_rgb(colour, 1.0, 1.0)]
 116         # Draw a 1-pixel wide rectangle of colour
 117         draw.rectangle((i, top_pos, i + 1, HEIGHT), (r, g, b))
 118         # Draw a line graph in black
 119         line_y = HEIGHT - (top_pos + (colours[i] * (HEIGHT - top_pos))) + top_pos
 120         draw.rectangle((i, line_y, i + 1, line_y + 1), (0, 0, 0))
 121     # Write the text at the top in black
 122     draw.text((0, 0), message, font=font, fill=(0, 0, 0))
 123     # Write text (test)
 124     maxMsg = "MAX:{:.1f}".format(vmax)
 125     durMsg = "HR:{:.1f}".format(span_time_h)
 126     minMsg = "MIN:{:.1f}".format(vmin)
 127     maxMsg_y = int( ((HEIGHT - top_pos)/(HEIGHT))*(HEIGHT*(1/4)) + top_pos - (font2_size/2) )
 128     durMsg_y = int( ((HEIGHT - top_pos)/(HEIGHT))*(HEIGHT*(2/4)) + top_pos - (font2_size/2) )
 129     minMsg_y = int( ((HEIGHT - top_pos)/(HEIGHT))*(HEIGHT*(3/4)) + top_pos - (font2_size/2) )
 130     maxMsg_x = int( WIDTH*(3/100) )
 131     durMsg_x = int( WIDTH*(3/100) )
 132     minMsg_x = int( WIDTH*(3/100) )
 133     draw.text((maxMsg_x, maxMsg_y), maxMsg, font=font2, fill=(0, 0, 0))
 134     draw.text((durMsg_x, durMsg_y), durMsg, font=font2, fill=(0, 0, 0))
 135     draw.text((minMsg_x, minMsg_y), minMsg, font=font2, fill=(0, 0, 0))
 136     st7735.display(img)
 137
 138
 139 # Get the temperature of the CPU for compensation
 140 def get_cpu_temperature():
 141     process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE, universal_newlines=True)
 142     output, _error = process.communicate()
 143     return float(output[output.index('=') + 1:output.rindex("'")])
 144
 145 def rel_to_abs(T,P,RH):
 146     """Returns absolute humidity given relative humidity.
 147
 148     Inputs:
 149     --------
 150     T : float
 151         Absolute temperature in units Kelvin (K).
 152     P : float
 153         Total pressure in units Pascals (Pa).
 154     RH : float
 155         Relative humidity in units percent (%).
 156
 157     Output:
 158     --------
 159     absolute_humidity : float
 160         Absolute humidity in units [kg water vapor / kg dry air].
 161
 162     References:
 163     --------
 164     1. Sonntag, D. "Advancements in the field of hygrometry". 1994. https://doi.org/10.1127/metz/3/1994/51
 165     2. Green, D. "Perry's Chemical Engineers' Handbook" (8th Edition). Page "12-4". McGraw-Hill Professional Publishing. 2007.
 166
 167     Version: 0.0.1
 168     Author: Steven Baltakatei Sandoval
 169     License: GPLv3+
 170     """
 171
 172     import math;
 173
 174     # Check input types
 175     T = float(T);
 176     P = float(P);
 177     RH = float(RH);
 178
 179     #debug
 180     # print('DEBUG:Input Temperature   (K)  :' + str(T));
 181     # print('DEBUG:Input Pressure      (Pa) :' + str(P));
 182     # print('DEBUG:Input Rel. Humidity (%)  :' + str(RH));
 183
 184     # Set constants and initial conversions
 185     epsilon = 0.62198 # (molar mass of water vapor) / (molar mass of dry air)
 186     t = T - 273.15; # Celsius from Kelvin
 187     P_hpa = P / 100; # hectoPascals (hPa) from Pascals (Pa)
 188
 189     # Calculate e_w(T), saturation vapor pressure of water in a pure phase, in Pascals
 190     ln_e_w = -6096*T**-1 + 21.2409642 - 2.711193*10**-2*T + 1.673952*10**-5*T**2 + 2.433502*math.log(T); # Sonntag-1994 eq 7; e_w in Pascals
 191     e_w = math.exp(ln_e_w);
 192     e_w_hpa = e_w / 100; # also save e_w in hectoPascals (hPa)
 193     # print('DEBUG:ln_e_w:' + str(ln_e_w)); # debug
 194     # print('DEBUG:e_w:' + str(e_w)); # debug
 195
 196     # Calculate f_w(P,T), enhancement factor for water
 197     f_w = 1 + (10**-4*e_w_hpa)/(273 + t)*(((38 + 173*math.exp(-t/43))*(1 - (e_w_hpa / P_hpa))) + ((6.39 + 4.28*math.exp(-t / 107))*((P_hpa / e_w_hpa) - 1))); # Sonntag-1994 eq 22.
 198     # print('DEBUG:f_w:' + str(f_w)); # debug
 199
 200     # Calculate e_prime_w(P,T), saturation vapor pressure of water in air-water mixture, in Pascals
 201     e_prime_w = f_w * e_w; # Sonntag-1994 eq 18
 202     # print('DEBUG:e_prime_w:' + str(e_prime_w)); # debug
 203
 204     # Calculate e_prime, vapor pressure of water in air, in Pascals
 205     e_prime = (RH / 100) * e_prime_w;
 206     # print('DEBUG:e_prime:' + str(e_prime)); # debug
 207
 208     # Calculate r, the absolute humidity, in [kg water vapor / kg dry air]
 209     r = (epsilon * e_prime) / (P - e_prime);
 210     # print('DEBUG:r:' + str(r)); # debug
 211
 212     return float(r);
 213
 214
 215 # Tuning factor for compensation. Decrease this number to adjust the
 216 # temperature down, and increase to adjust up
 217 factor = 2.25
 218
 219 cpu_temps = [get_cpu_temperature()] * 5
 220
 221 delay = 0.5  # Debounce the proximity tap
 222 mode = 0  # The starting mode
 223 last_page = 0
 224 light = 1
 225
 226 # Create a values dict to store the data
 227 variables = ["temperature",
 228              "pressure",
 229              "humidity",
 230              "humidity_abs",
 231              "light"]
 232 values = {} # Initialize values dictionary
 233 for v in variables:
 234     values[v] = [1] * WIDTH # Init a WIDTH-length list as value for each string in variables
 235
 236 # Create a varLenBuffer dict to store recent data
 237 varLenBuffer = {}
 238 for v in variables:
 239     varLenBuffer[v] = [] # Init an empty list for each string in variables
 240
 241 # Create a varLenBufferFlt dict to store recent data as floats only
 242 varLenBufferFlt = {}
 243 for v in variables:
 244     varLenBufferFlt[v] = [] # Init an empty list for each string in variables
 245
 246 # Create a fixLenBuffer dict to store data for displaying
 247 fixLenBuffer = {}
 248 for v in variables:
 249     fixLenBuffer[v] = [] # Init an empty list for each string in variables
 250
 251 pollDelay = 5.0
 252
 253 def pollSensors():
 254     # Desc: Update variables containing latest sensor tuples
 255     # Output: (time [ns], unit, float)
 256     #         now_temp_tuple (°C)
 257     #         now_pressure_tuple (hPa)
 258     #         now_humidity_tuple (%)
 259     #         now_humidity_abs_gkg_tuple (g water vapor / kg dry air)
 260     #         now_illuminance_tuple (lux)
 261     # Depends: time, bme280, ltr559, get_cpu_temperature(), rel_to_abs()
 262
 263     # Tell function to modify these global variables
 264     global now_temp_tuple
 265     global now_pressure_tuple
 266     global now_humidity_tuple
 267     global now_humidity_abs_gkg_tuple
 268     global now_illuminance_tuple
 269     # Initialize
 270     cpu_temps = []
 271     poll_time_ns_start = time.time_ns() # Get time reading (unix spoech, nanoseconds)
 272     # Get temperature reading
 273     cpu_temp = get_cpu_temperature() # get °C from CPU
 274     # Smooth out with some averaging to decrease jitter
 275     cpu_temps = cpu_temps[1:] + [cpu_temp]
 276     avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
 277     raw_temp = bme280.get_temperature() # get °C from BME280 sensor
 278     now_temp = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
 279     now_temp_tuple = (time.time_ns(), '°C', now_temp)
 280     # Get pressure reading
 281     now_time_ns = time.time_ns() # Get time reading (unix epoch, nanoseconds)
 282     now_pressure = bme280.get_pressure() # get hPa from BME280 sensor
 283     now_pressure_tuple = (time.time_ns(), 'hPa', now_pressure)
 284     # Get relative humidity reading
 285     now_humidity = bme280.get_humidity() # get % relative humidity from BME280 sensor
 286     now_humidity_tuple = (time.time_ns(), '%', now_humidity)
 287     # Calculate absolute humidity reading
 288     raw_temp_k = 273.15 + raw_temp; # convert sensor temp from degC to K
 289     now_pressure_pa = now_pressure * 100; # convert sensor pressure from hPa to Pa
 290     now_humidity_abs = rel_to_abs(raw_temp_k, now_pressure_pa, now_humidity); # calc kg/kg abs humidity
 291     now_humidity_abs_gkg = now_humidity_abs * 1000;
 292     now_humidity_abs_gkg_tuple = (time.time_ns(), 'g/kg', now_humidity_abs_gkg);
 293     # Get light reading
 294     proximity = ltr559.get_proximity() # get proximity reading
 295     if proximity < 10:
 296         now_illuminance = ltr559.get_lux() # get lux reading from LTR-559 sensor if nothing is nearby
 297         now_illuminance_tuple = (time.time_ns(), 'lux', now_illuminance)
 298     poll_time_ns_end = time.time_ns()
 299     #print('DEBUG:poll time (s):' + str((poll_time_ns_end - poll_time_ns_start)/1000000000))
 300
 301
 302 def dateIso8601Str():
 303     nowUTC = datetime.datetime.utcnow().replace(tzinfo=datetime.timezone.utc).isoformat()
 304     return str(nowUTC)
 305
 306 def medianSubset(listIn: list = [], listOutLen: int = 0) -> list:
 307     # Input: int:  listOutLen: quantity of elements in output list
 308     #        list: listIn: input list consisting of integers or floats
 309     # Output: list: ints/floats of specified size
 310     # Ref/Attrib: PEP 3107 typing https://stackoverflow.com/a/21384492
 311     # Version: 0.1.0
 312     #print('DEBUG:listOutLen:' + str(listOutLen))
 313     #print('DEBUG:listIn:' + str(listIn))
 314
 315     # Exit for invalid input
 316     if not isinstance(listOutLen, int):
 317         raise ValueError('ERROR:Not a valid int:' + str(listOutLen))
 318     else:
 319         if not listOutLen > 0:
 320             raise ValueError('ERROR:Invalid value:' + str(listOutLen))
 321     if not isinstance(listIn, list):
 322         raise ValueError('ERROR:Not a valid list:' + str(listOutLen))
 323     if not all([( (isinstance(x,int)) or (isinstance(x,float)) ) for x in listIn]):
 324         raise ValueError('ERROR:Input list contains something besides integers or floating point numbers.')
 325
 326     # Initialize listOut
 327     listOut = [None] * listOutLen
 328     #print('DEBUG:listOut:' + str(listOut))
 329
 330     # Calc listIn length
 331     listInLen = len(listIn)
 332     #print('DEBUG:listInLen:' + str(listInLen))
 333
 334     # Calc subset length float
 335     subsetLenFloat = ( (max([listInLen,listOutLen]) - 1) /min([listInLen,listOutLen]))
 336     subsetIndRatio = ( (listInLen)/(listOutLen) )
 337     #print('DEBUG:subsetLenFloat: %.5f' % subsetLenFloat)
 338     #print('DEBUG:subsetLenFloat2: %.5f' % subsetIndRatio)
 339
 340     # Iterate for each element in listOut
 341     for i_out in range(listOutLen):
 342         #print('DEBUG:i_out:' + str(i_out))
 343         ## Decide to expand or reduce listIn to produce listOut
 344         if listInLen > listOutLen:
 345             ### reduce listIn to listOut
 346             #print('DEBUG:listOutLen:' + str(listOutLen))
 347             #print('DEBUG:listInLen:' + str(listInLen))
 348             if i_out == 0:
 349                 #### Initialize subsetIndLo in first loop
 350                 subsetIndLo = int(0)
 351                 #print('DEBUG:subsetIndLo:' + str(subsetIndLo))
 352             #print('DEBUG:i_out:' + str(i_out))
 353             #### Calc indices of i_out'th subset of listIn
 354             subsetIndHi = (listInLen - 1) * (i_out + 1) // listOutLen
 355             subsetLen = subsetIndHi - subsetIndLo + 1
 356             #print('DEBUG:subsetIndLo:' + str(subsetIndLo))
 357             #print('DEBUG:subsetIndHi:' + str(subsetIndHi))
 358             #print('DEBUG:subsetLen:' + str(subsetLen))
 359             #### Extract subset from listIn using indices inclusively
 360             subset = listIn[ int(subsetIndLo) : int(subsetIndHi)+1 ]
 361             #print('DEBUG:subset:' + str(subset))
 362             #### Calculate median for subset
 363             subsetMedian = np.median(subset)
 364             #print('DEBUG:subset median:' + str(subsetMedian))
 365             #### Set listOut element
 366             listOut[i_out] = subsetMedian
 367             #### Housekeeping
 368             ##### Update subsetIndLo for next loop
 369             subsetIndLo = subsetIndHi + 1
 370             #print('DEBUG:Updated subsetIndLo:' + str(subsetIndLo))
 371         elif listOutLen > listInLen:
 372             ### Expand listIn to listOut
 373             #print('DEBUG:listOutLen:' + str(listOutLen))
 374             #print('DEBUG:listInLen:' + str(listInLen))
 375             #### Identify index list of lists mapping listIn to ListOut
 376             expandIndex = int(i_out / subsetLenFloat)
 377             expandIndex = min([expandIndex,(listInLen - 1)])
 378             #print('DEBUG:expandIndex:' + str(expandIndex))
 379             listOut[i_out] = listIn[expandIndex]
 380             #print('DEBUG:listOut[i_out]:' + str(listOut[i_out]))
 381         elif listOutLen == listInLen:
 382             listOut = listIn
 383             #print('DEBUG:end for loop===========')
 384     return listOut
 385
 386 def updateBuffer():
 387     global now_temp_tuple
 388     global now_pressure_tuple
 389     global now_humidity_tuple
 390     global now_humidity_abs_gkg_tuple
 391     global now_illuminance_tuple
 392     global varLenBuffer
 393     global fixLenBuffer
 394     global fixLenBufferFlt
 395     global span_time_h
 396     #print('DEBUG:This is the updateBuffer() function.')
 397     #print('DEBUG:===========================================================')
 398     #print('DEBUG:===========================================================')
 399     # Capture new sensor tuples
 400     pollSensors()
 401     #print('DEBUG:now_temp_tuple:' + str(now_temp_tuple))
 402     #print('DEBUG:now_pressure_tuple:' + str(now_pressure_tuple))
 403     #print('DEBUG:now_humidity_tuple:' + str(now_humidity_tuple))
 404     #print('DEBUG:now_humidity_abs_gkg_tuple:' + str(now_humidity_abs_gkg_tuple))
 405     #print('DEBUG:now_illuminance_tuple:' + str(now_illuminance_tuple))
 406
 407     # Append new sensor tuples to varying-length buffer
 408     ## Temperature
 409     varLenBuffer[variables[0]].append(now_temp_tuple)
 410     ## Pressure
 411     varLenBuffer[variables[1]].append(now_pressure_tuple)
 412     ## Relative Humidity
 413     varLenBuffer[variables[2]].append(now_humidity_tuple)
 414     ## Absolute Humidity
 415     varLenBuffer[variables[3]].append(now_humidity_abs_gkg_tuple)
 416     ## Illuminance
 417     varLenBuffer[variables[4]].append(now_illuminance_tuple)
 418     #print('DEBUG:varLenBuffer:' + str(varLenBuffer))
 419
 420     # Trim outdated sensor tuples from varying-length buffer
 421     ## iterate through each tuple list and remove old tuples
 422     varLenBufferTemp = []
 423     for v in variables:
 424         #varLenBufferTemp = varLenBuffer[v].copy()
 425         now_time_ns = time.time_ns() # get ns timestamp of now
 426         thn_time_ns = varLenBuffer[v][0][0] # get ns timestamp of earliest tuple
 427         dif_time_ns = now_time_ns - thn_time_ns # calc nanosecond difference
 428         #print('DEBUG:varLenBufferTTL:' + str(varLenBufferTTL))
 429         #print('DEBUG:now:' + str(now_time_ns))
 430         #print('DEBUG:thn:' + str(thn_time_ns))
 431         #print('DEBUG:dif:' + str(dif_time_ns))
 432         #print('DEBUG:dif(s):' + str(dif_time_ns / 1000000000))
 433         if dif_time_ns > varLenBufferTTL:
 434             varLenBuffer[v].pop(0) # discard earliest tuple if age > varLenBufferTTL
 435         print('DEBUG:Len of varLenBuffer[' + str(v) + ']:' + str(len(varLenBuffer[v])))
 436         #print('DEBUG:*******************************************')
 437         #print('DEBUG:varLenBuffer[variables[' + str(v) + ']]:' + str(varLenBuffer[v]))
 438         #print('DEBUG:*******************************************')
 439
 440     # Calculate buffer time span in hours
 441     ## Get earliest timestamp (use temperature tuples)
 442     first_time_ns = varLenBuffer[variables[0]][0][0]
 443     last_time_ns = varLenBuffer[variables[0]][-1][0]
 444     span_time_ns = int(last_time_ns - first_time_ns)
 445     span_time_h = float(span_time_ns / (10**9*60*60)) # nanoseconds to hours
 446
 447     # Convert tuple buffer into float buffer
 448     for v in variables:
 449         varLenBufferFlt[v].clear() # clear old float list
 450         #print('DEBUG:v:' + str(v))
 451         for t in varLenBuffer[v]:
 452             #print('DEBUG:t:' + str(t))
 453             #print('DEBUG:t[2]:' + str(t[2]))
 454             #print('DEBUG:------------------------------------------')
 455             #print('DEBUG:varLenBufferFlt[' + str(v) + ']:' + str(varLenBufferFlt[v]))
 456             #print('DEBUG:------------------------------------------')
 457             if isinstance(t[2], float):
 458                 varLenBufferFlt[v].append(float(t[2])) # build new float list
 459             else:
 460                 varLenBufferFlt[v].append(float(-273)) # add obvious zero otherwise
 461                 #print('DEBUG:varLenBufferFlt[' + str(v) + ']:' + str(varLenBufferFlt[v]))
 462
 463     # Compress/expand buffer to fixed-length buffer
 464     for v in variables:
 465         #print('DEBUG:varLenBufferFlt[0]:' + str(varLenBufferFlt[variables[0]]))
 466         fixLenBuffer[v] = medianSubset(varLenBufferFlt[v], WIDTH)
 467         print('DEBUG:Len of fixLenBuffer[' + str(v) + ']:' + str(len(fixLenBuffer[v])))
 468         #print('DEBUG:fixLenBuffer[' + str(v) + ']:' + str(fixLenBuffer[v]))
 469
 470
 471 # The main loop
 472 try:
 473     # Schedule tasks
 474     # schedule.every(1).second.do(updateBuffer)
 475     schedule.every().minute.at(":00").do(updateBuffer)
 476     # schedule.every().minute.at(":05").do(updateBuffer)
 477     # schedule.every().minute.at(":10").do(updateBuffer)
 478     # schedule.every().minute.at(":15").do(updateBuffer)
 479     # schedule.every().minute.at(":20").do(updateBuffer)
 480     # schedule.every().minute.at(":25").do(updateBuffer)
 481     # schedule.every().minute.at(":30").do(updateBuffer)
 482     # schedule.every().minute.at(":35").do(updateBuffer)
 483     # schedule.every().minute.at(":40").do(updateBuffer)
 484     # schedule.every().minute.at(":45").do(updateBuffer)
 485     # schedule.every().minute.at(":50").do(updateBuffer)
 486     # schedule.every().minute.at(":55").do(updateBuffer)
 487     pollSensors() # initial run to start up sensors
 488     time.sleep(1) # pause to give sensors time to initialize
 489     updateBuffer() # initial run
 490
 491     while True:
 492         proximity = ltr559.get_proximity()
 493
 494         # If the proximity crosses the threshold, toggle the display mode
 495         if proximity > 1500 and time.time() - last_page > delay:
 496             mode += 1
 497             mode %= len(variables)
 498             last_page = time.time()
 499
 500         # Run scheduled tasks
 501         schedule.run_pending()
 502
 503         # One display mode for each variable
 504         if mode == 0:
 505             # variable = "temperature"
 506             ## run function to display latest temp values in variables[mode] list
 507             unit = "°C"
 508             cpu_temp = get_cpu_temperature()
 509             # Smooth out with some averaging to decrease jitter
 510             cpu_temps = cpu_temps[1:] + [cpu_temp]
 511             avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
 512             raw_temp = bme280.get_temperature()
 513             data = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
 514             #display_text(variables[mode], data, unit)
 515             display_text2(variables[mode],data,unit,fixLenBuffer)
 516
 517         if mode == 1:
 518             # variable = "pressure"
 519             unit = "hPa"
 520             data = bme280.get_pressure()
 521             #display_text(variables[mode], data, unit)
 522             display_text2(variables[mode],data,unit,fixLenBuffer)
 523
 524         if mode == 2:
 525             # variable = "humidity"
 526             unit = "%"
 527             data = bme280.get_humidity()
 528             #display_text(variables[mode], data, unit)
 529             display_text2(variables[mode],data,unit,fixLenBuffer)
 530
 531         if mode == 3:
 532             # variable = "humidity_abs"
 533             unit = "g/kg"
 534             raw_temp = bme280.get_temperature() # get °C from BME280 sensor
 535             raw_temp_k = 273.15 + raw_temp; # convert sensor temp from degC to K
 536             now_pressure = bme280.get_pressure() # get hPa from BME280 sensor
 537             now_pressure_pa = now_pressure * 100; # convert sensor pressure from hPa to Pa
 538             now_humidity = bme280.get_humidity() # get % relative humidity from BME280 sensor
 539             now_humidity_abs = rel_to_abs(raw_temp_k,now_pressure_pa,now_humidity); # calc [kg water / kg dry air] abs humidity
 540             now_humidity_abs_gkg = now_humidity_abs * 1000; # convert kg/kg to g/kg abs humidity
 541             data = now_humidity_abs_gkg;
 542             # print('DEBUG:raw_temp:' + str(raw_temp));
 543             # print('DEBUG:raw_temp_k:' + str(raw_temp_k));
 544             # print('DEBUG:now_pressure:' + str(now_pressure));
 545             # print('DEBUG:now_pressure_pa:' + str(now_pressure_pa));
 546             # print('DEBUG:now_humidity:' + str(now_humidity));
 547             # print('DEBUG:now_humidity_abs_gkg:' + str(data));
 548             display_text2(variables[mode],data,unit,fixLenBuffer)
 549
 550         if mode == 4:
 551             # variable = "light"
 552             unit = "Lux"
 553             if proximity < 10:
 554                 data = ltr559.get_lux()
 555             else:
 556                 data = 1
 557             #display_text(variables[mode], data, unit)
 558             display_text2(variables[mode],data,unit,fixLenBuffer)
 559
 560
 561
 562 # Exit cleanly
 563 except KeyboardInterrupt:
 564     sys.exit(0)