display.py

#!/usr/bin/env python3

import time
import colorsys
import os
import sys
import ST7735

from subprocess import PIPE, Popen
from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont
from fonts.ttf import RobotoMedium as UserFont
import logging
import sensors

# factor = 2.25
factor = 0

HUE_MAX = 240 / 360
HUE_MIN = 0
HUE_GOOD = 120 / 360
HUE_WARNING = 50/360
HUE_DANGER = 0

#comfort ranges
TEMP_LOW = 16
TEMP_HIGH = 24
HUMIDITY_LOW = 30
HUMIDITY_HIGHT = 60

logging.basicConfig(
    format='%(asctime)s.%(msecs)03d %(levelname)-8s %(message)s',
    level=logging.INFO,
    datefmt='%Y-%m-%d %H:%M:%S')

logging.info("""all-in-one.py - Displays readings from all of Enviro plus' sensors
Press Ctrl+C to exit!
""")

# Create ST7735 LCD display class
st7735 = ST7735.ST7735(
    port=0,
    cs=1,
    dc=9,
    backlight=12,
    rotation=270,
    spi_speed_hz=10000000
)

# Initialize display
st7735.begin()

WIDTH = st7735.width
HEIGHT = st7735.height

# Set up canvas and font
img = Image.new('RGB', (WIDTH, HEIGHT), color=(0, 0, 0))
draw = ImageDraw.Draw(img)
path = os.path.dirname(os.path.realpath(__file__))
font_size = 20
font = ImageFont.truetype(UserFont, font_size)

message = ""

# The position of the top bar
top_pos = 25

#Normalise the values for display
def normalise_data(data, max, min):
    range = max - min

    # Restrict and normalize the data
    if data < min:
        normalised = 0
    elif data > max:
        normalised = 1
    else:
        normalised = (data - min) / range

    return normalised

#Convert a temperature to a colour
def temperature_colour(data):
    hue_range = HUE_MAX - HUE_MIN

    # Restrict and normalize the data
    temp_scaled = normalise_data(data, TEMP_HIGH, TEMP_LOW)

    # As we want blue for cold and red for hot we take the scaled temperature away from 1.
    temp_scaled = 1 - temp_scaled
    #Now we convert it to a hue
    temp_hue = (temp_scaled - HUE_MIN) / hue_range
    return temp_hue
     
# Displays data and text on the 0.96" LCD
def display_text(hue, data, unit):
    
    # Format the variable name and value
    message = "{:.1f} {}".format(data, unit)
    logging.info(message)
    draw.rectangle((0, 0, WIDTH, HEIGHT), (255, 255, 255))

    # Convert the values to colours from red to blue
    r, g, b = [int(x * 255.0) for x in colorsys.hsv_to_rgb(hue, 1.0, 1.0)]
    # Draw a rectangle of colour
    draw.rectangle((0, top_pos, WIDTH, HEIGHT), (r, g, b))
    # Write the text at the top in black
    draw.text((0, 0), message, font=font, fill=(0, 0, 0))
    st7735.display(img)

delay = 0.5  # Debounce the proximity tap
mode = 0  # The starting mode
last_page = 0
light = 1

# Create a values dict to store the data
variables = ["temperature",
             "pressure",
             "humidity",
             "light",
             "oxidised",
             "reduced",
             "nh3"]

values = {}

for v in variables:
    values[v] = [1] * WIDTH

# The main loop
try:
    while True:
        proximity = sensors.get_proximity()

        # If the proximity crosses the threshold, toggle the mode
        # if proximity > 1500 and time.time() - last_page > delay:
        #     mode += 1
        #     mode %= len(variables)
        #     last_page = time.time()

        # One mode for each variable
        if mode == 0:
            # variable = "temperature"
            unit = "C"
            data = sensors.get_adjusted_temperature(config.factor)
            display_text(temperature_colour(data), data, unit)

        """ if mode == 1:
            # variable = "pressure"
            unit = "hPa"
            data = sensors.get_pressure()
            display_text(variables[mode], data, unit)

        if mode == 2:
            # variable = "humidity"
            unit = "%"
            data = sensors.get_humidity(config.factor)
            display_text(variables[mode], data, unit)

        if mode == 3:
            # variable = "light"
            unit = "Lux"
            data =sensors.get_light()
            display_text(variables[mode], data, unit)

        if mode == 4:
            # variable = "oxidised"
            unit = "kO"
            data = sensors.get_oxidising()
            display_text(variables[mode], data, unit)

        if mode == 5:
            # variable = "reduced"
            unit = "kO"
            data = sensors.get_reducing()
            display_text(variables[mode], data, unit)

        if mode == 6:
            # variable = "nh3"
            unit = "kO"
            data = sensors.get_nh3()
            display_text(variables[mode], data, unit) """

# Exit cleanly
except KeyboardInterrupt:
    sys.exit(0)