CP/PC364 Data Communications & Networks Laboratory

I²C communication with the Arduino

Overview

The I²C (Inter-Integrated Circuit) protocol is used for communication between many devices. It is more complicated than either UART or SPI, because it allows several devices to share a common bus, but it it useful for this same reason.

Objectives

The objectives for this lab are:

to learn how to use the Arduino I²C interface
to connect one I²C digital sensor for proper operation
to write a test sketch to show the I²C digital sensor in operation

Background

The I²C (Inter-Integrated Circuit) communication protocol allows several device to communicate using only two wires. One device acts as a master, and all of the other devices are slaves. The Arduino board has an The I²C bus built-in so it can be used to study I²C communications.

Equipment

Arduino
bench supply, oscilloscope
breadboard, debugger board, resistors, capacitors
one I²C device

Task

From the Arduino documentation, what pins are used for I²C communication?
The I²C device lines need pull-up resisors. Does the Arduino have internal pull-up resistors or will you need to add them externally? If the latter, what values will you need?
Consult the data sheet for the device to figure out how to wire it up.
What is the address of the device?
Create a sketch to communicate with the device, using the LCD for display. Hint: Look online: There are lots of examples out there!!!!!
Demonstrate your circuit to the lab supervisor.