Time to Get Wired

Bring your caffeine and your Arduino, and learn how to use I2C and Arduino's Wire library.

We'll be using a DS1307 Real Time Clock (RTC) module. This is crucial for those projects where your Arduino needs to know not just milliseconds elapsed, but true time-of-day.
Potential applications:

• Turn your electric blanket on at bedtime
• Reminder light to set the trash bin out on Wednesdays
• Check water level or temperature every afternoon

RTC Modules:
https://www.sparkfun.com/products/99
or
http://www.vetco.net/catalog/product_info.php?products_id=12866
or kit form
http://learn.adafruit.com/ds1307-real-time-clock-breakout-board-kit/overview

Once you've learned how to connect up I2C and use the Wire library, you will then be able to connect to and use a wide variety of sensors and devices via I2C.

Compelling Examples:
https://www.sparkfun.com/products/9000
https://www.sparkfun.com/products/10251
https://www.sparkfun.com/products/11295
http://learn.adafruit.com/adafruit-ina219-current-sensor-breakout
http://learn.adafruit.com/i2c-spi-lcd-backpack
http://learn.adafruit.com/adafruit-led-backpack/0-dot-56-seven-segment-backpack
http://learn.adafruit.com/tsl2561/overview
http://www.vetco.net/catalog/product_info.php?products_id=13579
http://www.vetco.net/catalog/product_info.php?products_id=13806

There are some things you need to know about how I2C works electrically. We'll cover that by looking at a few schematic examples and discussing.

Then we'll look at how data actually travels across the wires using an I2C analyzer. Seeing the traces painted on the screen makes it much easier to get the gist of what's going on.

Finally we'll run some code examples on our own boards, and find out what time it is.

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• In order to participate you will need laptop, Arduino, USB cable for your Arduino, an I2C device, breadboard and jumpers. I will supply the resistors.

Examples:

Breadboard

http://www.vetco.net/catalog/product_info.php?products_id=14433

Jumpers

http://www.vetco.net/catalog/product_info.php?products_id=14266 (http://www.vetco.net/catalog/product_info.php?products_id=14264)

Note that if you have a second Arduino, bring that and learn how to use I2C to talk between 2 Arduinos.