Storing data internally – EEPROM

Sometimes we want to store some values inside the Arduino even when we turn it off. Luckily, each Arduino has an internal Electrically Erasable Programmable Read-Only Memory (EEPROM) just for that.

A note for using EEPROM–—the EEPROMs inside the Arduinos have a life cycle of 100,000 reads/writes. It may seem a lot, but it isn't. Only use the EEPROM when strictly needed.

Here we will program Arduino to record how many times we pressed a button. If the power is cut, it will still remember the last count using the EEPROM.

Getting ready

Following are the ingredients needed to execute this recipe:

• An Arduino Board connected to the computer via USB

• A push button

How to do it…

This recipe is based on the Button with no resistor recipe from Chapter 3, Working with Buttons. It uses the same hardware implementation with a different code.

The following code will read the last known button press count from the EEPROM and then, at each button press, will add one to that value...