Published April 7, 2019 © CC BY-NC-SA

Time To Live

How long do you have? A magic book to tell you exactly that!

BeginnerFull instructions provided20 hours794

Things used in this project

Hardware components

Raspberry Pi 3 Model B

Push Button (any)

Adafruit Standard LCD - 16x2 White on Blue

Software apps and online services

Raspberry Pi Raspbian

Hand tools and fabrication machines

Dremel 4300

Bookbinders Glue

Fire

Story

Overview

Below a quick overview of the content.

Introduction and showcase video
Book
Electronics
Code
Result

Introduction & Showcase Video

Combining the magic of watching all the Harry Potter movies in a week and the networking term TTL (Time To Live), we're going to build our own black magic book, showing how long you have to live.

Project Video

Book

It starts with finding an old book to use. Make sure it's nice and thick so you have plenty of space for the electronics. A great place to look are thrift stores, they have loads of cheap old books. In this case I've found a medical book from the 80's. Perfect, as it has a lot of cool images to use for styling.

Medical Book

Now we have our book, we're going to glue most pages together to create a nice "block". I've used some bookbinder's glue because it dries nice and see through. I think you can also use different types, but I haven't tested it. Put some glue between the pages and press them firmly.

Gluing pages together

To speed things up you can also glue the sides together, a combo of this and full page gluing creates a solid block.

Pages sides glued

After drying, it's time to cut out our electronics compartment, a Dremel with the woodcutting wheel works perfectly. Make sure to wear some protection, it creates a lot of dust.

Cutting out a compartment

That's one nice compartment, just add some extra duct tape for strength. Full instructions for creating a secret book compartment, can be found here.

Good old ducttape to cover up some mistakes

Next step is adding a "lid" to our compartment. Gluing some pages together gives us a basic lid. Adding a magnet means we can open and close our compartment.

Cut out a little indent and glue both the magnet (next to our compartment) and metal plate (bottom of lid) in place.

Magnet and metal plate

The magnet glued in place

With our compartment and lid in place, our book is almost done. To give the visible page the right (creepy) look and feel you can do the following:

Cutting and gluing images on the page (skulls and plants in this case)
Burning the images/pages and submerging them in water
Carving a sentence into the page and going over it with charcoal
Anything else that comes to mind, you can go nuts...

Styled page

Electronics

Now we can move on to the electronics. We will need the following parts:

Raspberry Pi (Arduino,...)
A push button (any)
Small LCD screen
Powerbank or Powerplug

These are two great tutorials to wire up the button and screen.

With everything wired up, measure the button/screen and cut holes into the lid for a snug fit.

Code

Almost there!

The only thing left is the magic part. You can find the full code in the attachments.

For good measure, a quick overview of the logic:

Listen if button is pushed
If so, generate a time(amount of seconds) and display it
Button is not pushed, check if the time is 0 If there's time left, lower it by one, and display what's leftNo time remaining, say Bye Bye

You can tweak the amount of time you give to the unfortunates in the following line of code:

number = random.randint(1,60)

You can also change the messages displayed in these lines:

lcdShowMessage("Time to live", lcdLine1)
lcdShowMessage("Bye Bye" , lcdLine2)
lcdShowMessage(str(number) , lcdLine2)

Result

And that's all!

Now we have a magic spell book, perfect for a very early Halloween!

Final look and feel

code.py

# Import libraries
from __future__ import print_function
import time
import datetime
import schedule
import RPi.GPIO as io
import random
io.setmode(io.BCM)

print("Hi, this is Time To Live")

#Setup the pins of the Raspberry

buttonPins = 21
io.setup(buttonPins, io.IN, pull_up_down=io.PUD_UP)

# Pins for the LCD Screen
# Register Select
lcdRs = 7
# Enable or Strobe
lcdE = 8
# Data pins
lcdData4 = 25
lcdData5 = 24
lcdData6 = 23
lcdData7 = 18
# Setup LCD Pins
io.setup(lcdE, io.OUT)
io.setup(lcdRs, io.OUT)
io.setup(lcdData4, io.OUT)
io.setup(lcdData5, io.OUT)
io.setup(lcdData6, io.OUT)
io.setup(lcdData7, io.OUT)

#LCD Constants
# Characters per line
lcdWidth = 16
lcdChr = True
lcdCmd = False
# LCD Ram address 1st line
lcdLine1 = 0x80
# LCD Ram address 2nd line
lcdLine2 = 0xC0
# Timing
lcdPulse = 0.0005
lcdDelay = 0.0005

# LCD Screen setup
def lcdByte(bits, mode):
    # Send byte to data pins
    # bits = data
    # mode = True  for character
    #        False for command

    io.output(lcdRs, mode)  # RS

    # High bits
    io.output(lcdData4, False)
    io.output(lcdData5, False)
    io.output(lcdData6, False)
    io.output(lcdData7, False)
    if bits & 0x10 == 0x10:
        io.output(lcdData4, True)
    if bits & 0x20 == 0x20:
        io.output(lcdData5, True)
    if bits & 0x40 == 0x40:
        io.output(lcdData6, True)
    if bits & 0x80 == 0x80:
        io.output(lcdData7, True)

    # Toggle 'Enable' pin
    lcdToggleEnable()

    # Low bits
    io.output(lcdData4, False)
    io.output(lcdData5, False)
    io.output(lcdData6, False)
    io.output(lcdData7, False)
    if bits & 0x01 == 0x01:
        io.output(lcdData4, True)
    if bits & 0x02 == 0x02:
        io.output(lcdData5, True)
    if bits & 0x04 == 0x04:
        io.output(lcdData6, True)
    if bits & 0x08 == 0x08:
        io.output(lcdData7, True)

    # Toggle 'Enable' pin
    lcdToggleEnable()


def lcdToggleEnable():
    # Toggle enable
    time.sleep(lcdDelay)
    io.output(lcdE, True)
    time.sleep(lcdPulse)
    io.output(lcdE, False)
    time.sleep(lcdDelay)


# Initialise LCD Display
lcdByte(0x33,lcdCmd) # 110011 Initialise
lcdByte(0x32,lcdCmd) # 110010 Initialise
lcdByte(0x06,lcdCmd) # 000110 Cursor move direction
lcdByte(0x0C,lcdCmd) # 001100 Display On,Cursor Off, Blink Off
lcdByte(0x28,lcdCmd) # 101000 Data length, number of lines, font size
lcdByte(0x01,lcdCmd) # 000001 Clear display
time.sleep(lcdDelay)

def lcdShowMessage(message, line):
    # Send string to display

    message = message.ljust(lcdWidth, " ")

    lcdByte(line, lcdCmd)

    for i in range(lcdWidth):
        lcdByte(ord(message[i]), lcdChr)
        
# We have 16 chars
lcdShowMessage("Time to live", lcdLine1)
number = None

while True:

    time.sleep(0.2)

    # Listen for the press, if pressed generate new number
    if io.input(buttonPins) == False: 

        # Generate the number of seconds to display
        number = random.randint(1,60)

        # Display  time left
        lcdShowMessage(str(number) , lcdLine2)
        time.sleep(0.8)

    #Button not pressed, we don't need to generate a new number
    elif number != None:

        # Check if there's time left
        if number > 0:
            #Lower the amount of seconds and display
            number -= 1
            time.sleep(0.8)
            lcdShowMessage(str(number) , lcdLine2)

        else:
            # None left, bye bye
            lcdShowMessage("Bye Bye" , lcdLine2)

Credits

Thanks to RaspberryPi-Spy, O'Reilly, and Brett & Kate McKay.

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Time To Live

Time To Live

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Overview

Introduction & Showcase Video

Book

Electronics

Code

Result

Code

code.py

Credits

Comments

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