#### Overview of this book

The mission of this book is to integrate technology with the tools that children already use for crafts so that they feel that the technology is an extension of their playtime. We use coding, sensors, and micro-controllers integrated with art and craft supplies, origami, and Playdough. There are 10 fun-filled chapters that talk to children directly, and give clear instructions for non-technical parents too. We use Arduino as the controller of choice due to its easy availability and large community. By the end of the book, children will comfortably be able to set up their Arduino, read and understand code, manipulate code, and ultimately write their own code for projects. They will also be able to use basic sensors and know how components connect to each other. All the learning takes place with lots of colorful pictures and the circuits are neatly presented using wiring.
Arduino for Kids
Credits
Foreword
www.PacktPub.com
Customer Feedback
Preface
Free Chapter
The World around Us
Systems and Logic
Components and Connections
The Magic Wand
Safety Box
Make a Friend
Save Energy
High 5!
Plant, Meet Arduino!

## Wait, we need voltage!

Now, it may have become apparent after explaining how ADC's work, that the Arduino can measure only an analog voltage. But our LDR changes its resistance depending on the amount of light falling on it. So how can we effectively change the voltage across the Arduino depending on the change of the resistance of the LDR?

We use a voltage divider!

A voltage divider is a very fundamental and simple circuit which basically divides a larger voltage into a smaller one depending on the values of the resistors in its circuit.

A voltage divider uses two resistors in series with an input voltage and can output an output voltage that is a fraction of the input.

A voltage divider

Image source: https://cdn.sparkfun.com/r/600-600/assets/4/0/3/a/e/511948ffce395f7f47000000.png

The output voltage depends on the resistances and the input voltage by the following equation:

Now, using this circuit, along with our LDR, we can manipulate the voltage input into our Arduino. All we have to do...