Introduction: Humidity Spy Book
After some years dedicated to Kindle lobby, it is time to stand up for the classic paper book, which is far from perfect as the spoon and of course it cannot be used to eat soup.
One friend that works as a librarian told me that humidity is the key factor in books conservation, so I have decided to make this spy book to measure humidity right on the shelves, providing clear traffic lights:
1. green (no problem)
2. yellow (you should fix those leaks)
3. red (you may need Noah's Ark at this point)
Let's start with instructions...
Step 1: Requirements
1. Arduino One
2. DHT 11 sensor
3. Forgettable Hard book cover (please do not use Roni Bandinis books for this purpose)
4. 3 leds
5. 3 220ohm resistors
6. 9V Battery
7. 1 switch
8. Some wires, a nail, cutter and glue
Step 2: Cover Preparation
Using the cutter, separate book contents from book cover. Then use the nail to make 3 holes for the leds and one rectangular hole for the switch.
Step 3: Circuit
Circuit is easy.
Just connect each led to a resistor. Green led + to pin 2, yellow led + to pin 3 and red led + to pin 4. The other side of all leds to the ground.
Humidity sensor may have 3 or 4 pins. In any case, connect 5V and ground to those pins in Arduino and signal to pin #7.
You may want to add a switch to the battery. In this case just put the switch between + 9V cable and the Arduino.
After testing, remove the breadboard and insert the circuit inside the Book Cover.
Step 4: Software
You need to install DHT library. Then upload BookCare.ino to Arduino.
Step 5: Demo
It is all set. Just turn the spy book on and you will be able to monitor Humidity right on place. Long life to your paper books!.