Beagle Board - beagleboard.org
Jeremy Palmer
Published

Indoor-Outdoor Temperature Sensors

Houston weather changes drastically from day to day and I need an easy way to tell what the outdoor temperature is each day.

EasyFull instructions provided10 hours390
Indoor-Outdoor Temperature Sensors

Things used in this project

Hardware components

PocketBeagle
BeagleBoard.org PocketBeagle
×1
DHT11 Temperature & Humidity Sensor
DHT11 Temperature & Humidity Sensor
×2
Breadboard (generic)
Breadboard (generic)
×1
Pushbutton switch 12mm
SparkFun Pushbutton switch 12mm
×1
Solderless Breadboard Half Size
Solderless Breadboard Half Size
×1

Hand tools and fabrication machines

Soldering iron (generic)
Soldering iron (generic)
3D Printer (generic)
3D Printer (generic)

Story

Read more

Custom parts and enclosures

Outside Box Bottom

This part is the lower portion of the outside box to hold the second temperature sensor. There is a hole in the side to allow the wires to enter the box. The slot in the side will allow you to take the bread board out of the box if needed.

Main Box Assembly

This is the SolidWorks Assembly of the main box to hold the large breadboard. I used this to align the holes for bolts and lid sizes.

Main Box Compartment

This part is the main container for the large breadboard. There are holes in the side to allow the outdoor temperature sensor and power cords to connect. The bolt holes are sized to take a 3/8" long 4-40 screw when 3D printed.

Upper Main Lid

This lid covers the taller portion of the main compartment above the PocketBeagle.

Lower Main Lid

This part is the lid to cover the lower portion of the main box compartment. There is an oddly shaped divot in the middle to allow the temperature sensor to be exposed while also covering the wires inside from sight.

Outside Sensor Box Assembly

This is the assembly used to make sure that the two components for the outdoor box would fit together.

Outside Box Lid

This part is the lid for the outside box. There is a hole in the middle to allow air to the temperature sensor, and the long protrusion indexes with the slot in the lower piece.

Schematics

Temperature Station Schematic

Schematic bznggnrq7l

Code

TemperatureSensor.py

Python
This is the code that runs the PocketBeagle on start up to let my temperature sensor work.
#Jeremy Palmer
#Rice University 
#ENGI 301 - Spring 2018

#This code will take the temperature and humidity data from two DHT11 sensors
#and display them on a screen. A button is used to initialize the reading.
#See Hackster for a more detailed description of the project.


#imports
import time
import Adafruit_DHT
from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont

import ST7735 as TFT
import Adafruit_GPIO as GPIO
import Adafruit_GPIO.SPI as SPI

GPIO_BASE_PATH               = "/sys/class/gpio"

# GPIO direction
IN                           = True
OUT                          = False

# GPIO output state
LOW                          = "0"
HIGH                         = "1"

# Button GPIO values
BUTTON0                      = (2, 0)           # gpio64

#set screen dimensions
WIDTH = 128
HEIGHT = 160
SPEED_HZ = 4000000

# BeagleBone Black configuration.
DC = 'P2_33'
RST = 'P2_35'
SPI_PORT = 2
SPI_DEVICE = 0

# Create TFT LCD display class.
disp = TFT.ST7735(
    DC,
    rst=RST,
    spi=SPI.SpiDev(
        SPI_PORT,
        SPI_DEVICE,
        max_speed_hz=SPEED_HZ))
        
# Sensor should be set to Adafruit_DHT.DHT11,
# Adafruit_DHT.DHT22, or Adafruit_DHT.AM2302.
sensor1 = Adafruit_DHT.DHT11
sensor2 = Adafruit_DHT.DHT11

#set the temperature data pins
pin2 = "GPIO1_12"
pin1 = "GPIO1_14"

# ------------------------------------------------------------------------
# GPIO / ADC access library
# ------------------------------------------------------------------------
import os


def gpio_setup(gpio, direction, default_value=False):
    """Setup GPIO pin
    
      * Test if GPIO exists; if not create it
      * Set direction
      * Set default value
    """
    gpio_number = str((gpio[0] * 32) + gpio[1])
    path        = "{0}/gpio{1}".format(GPIO_BASE_PATH, gpio_number)
    
    if not os.path.exists(path):
        # "echo {gpio_number} > {GPIO_BASE_PATH}/export"
        print("Create GPIO: {0}".format(gpio_number))
        with open("{0}/export".format(GPIO_BASE_PATH), 'w') as f:
            f.write(gpio_number)
    
    if direction:
        # "echo in > {path}/direction"
        with open("{0}/direction".format(path), 'w') as f:
            f.write("in")
    else:
        # "echo out > {path}/direction"
        with open("{0}/direction".format(path), 'w') as f:
            f.write("out")
        
    if default_value:
        # "echo {default_value} > {path}/value"
        with open("{0}/value".format(path), 'w') as f:
            f.write(default_value)
    
# End def


def gpio_set(gpio, value):
    """Set GPIO ouptut value."""
    gpio_number = str((gpio[0] * 32) + gpio[1])
    path        = "{0}/gpio{1}".format(GPIO_BASE_PATH, gpio_number)
    
    # "echo {value} > {path}/value"
    with open("{0}/value".format(path), 'w') as f:
        f.write(value)

# End def


def gpio_get(gpio):
    """Get GPIO input value."""
    gpio_number = str((gpio[0] * 32) + gpio[1])
    path        = "{0}/gpio{1}".format(GPIO_BASE_PATH, gpio_number)
    
    # "cat {path}/value"
    with open("{0}/value".format(path), 'r') as f:
        out = f.read()
    
    return float(out)

# End def

# Define a function to create rotated text.  Unfortunately PIL doesn't have good
# native support for rotated fonts, but this function can be used to make a
# text image and rotate it so it's easy to paste in the buffer.
def draw_rotated_text(image, text, position, angle, font, fill=(255,255,255)):
    # Get rendered font width and height.
    draw = ImageDraw.Draw(image)
    width, height = draw.textsize(text, font=font)
    # Create a new image with transparent background to store the text.
    textimage = Image.new('RGBA', (width, height), (0,0,0,0))
    # Render the text.
    textdraw = ImageDraw.Draw(textimage)
    textdraw.text((0,0), text, font=font, fill=fill)
    # Rotate the text image.
    rotated = textimage.rotate(angle, expand=1)
    # Paste the text into the image, using it as a mask for transparency.
    image.paste(rotated, position, rotated)


def show_temp():

    # Try to grab a sensor reading.  Use the read_retry method which will retry up
    # to 15 times to get a sensor reading (waiting 2 seconds between each retry).
    humidity1, temperature1 = Adafruit_DHT.read_retry(sensor1, pin1)
    humidity2, temperature2 = Adafruit_DHT.read_retry(sensor2, pin2)

    
    #convert temperature from C to F
    temperature1F = (temperature1*1.8) + 32
    temperature2F = (temperature2*1.8) + 32
    


    # Get a PIL Draw object to start drawing on the display buffer.
    draw = disp.draw()


    # Load default font.
    font = ImageFont.load_default()

    # Write the text on the display for the indoor and outdoor temperature
    draw_rotated_text(disp.buffer,  'Today\'s Weather:    ', (0, 150), 180, font, fill=(255,255,255))
    draw_rotated_text(disp.buffer,  'Outdoor  Temp ={0:0.1f}*F'.format(temperature2F), (0, 135), 180, font, fill=(255,255,255))
    draw_rotated_text(disp.buffer,  'Outdoor Humid ={0:0.1f} %'.format(humidity2), (0, 125), 180, font, fill=(255,255,255))

    draw_rotated_text(disp.buffer,  'Indoor  Temp ={0:0.1f}*F'.format(temperature1F), (0, 105), 180, font, fill=(255,255,255))
    draw_rotated_text(disp.buffer,  'Indoor Humid ={0:0.1f} %'.format(humidity2), (0, 95), 180, font, fill=(255,255,255))

    #make a face for fun
    draw.ellipse((10, 0, 110, 90), outline=(0,0,0), fill=(0,255,0))

    draw.ellipse((25, 45, 55, 75), outline=(255,255,255), fill=(255,0,200))
    draw.ellipse((65, 45, 95, 75), outline=(255,255,255), fill=(255,0,200))
    draw.ellipse((25, 20, 95, 40), outline=(255,255,255), fill=(0,0,200))

    # Write buffer to display hardware, must be called to make things visible on the
    # display!
    disp.display()


#set up the display and button
def setup_temp():
    gpio_setup(BUTTON0, IN)
    
    disp.begin()
    # Clear the display to a red background.
    # Can pass any tuple of red, green, blue values (from 0 to 255 each).
    disp.clear((255, 0, 0))
    disp.display()


#main driver function
if __name__ == '__main__':
    setup_temp()
    
    while (True):
        if (gpio_get(BUTTON0) == 0):
            show_temp() 
            time.sleep(15.0)
            disp.clear((255, 0, 0))
            disp.display()
        time.sleep(1.0)

    cleanup_temp()

Credits

Jeremy Palmer

Jeremy Palmer

1 project • 1 follower

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