Reading I2C sensor data in Arduino - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does I2C stand for and what is its main purpose?

I2C stands for Inter-Integrated Circuit. It is a communication protocol used to connect multiple devices (like sensors and microcontrollers) using just two wires: SDA (data) and SCL (clock).

beginner

Which Arduino library is commonly used to communicate with I2C devices?

The Wire library is used in Arduino to communicate with I2C devices. It handles sending and receiving data over the I2C bus.

beginner

What are the two main steps to read data from an I2C sensor in Arduino?

1. Request data from the sensor using Wire.requestFrom().<br>2. Read the incoming bytes using Wire.read().

beginner

Why do you need to know the sensor's I2C address before reading data?

Each I2C device has a unique address. You must specify this address when communicating so the microcontroller talks to the correct device on the bus.

beginner

What is the purpose of Wire.begin() in an Arduino I2C program?

Wire.begin() initializes the I2C bus and prepares the Arduino to communicate as a master device with I2C sensors.

Which two wires are used in I2C communication?

A MOSI and MISO

B SDA and SCL

C TX and RX

D VCC and GND

I2C uses SDA (data line) and SCL (clock line) for communication.

What Arduino function starts the I2C bus as a master?

A Wire.open()

B Wire.start()

C Wire.begin()

D Wire.init()

Wire.begin() initializes the I2C bus for the Arduino.

How do you request 6 bytes of data from an I2C sensor at address 0x40?

A Wire.receive(0x40, 6);

B Wire.read(0x40, 6);

C Wire.send(0x40, 6);

D Wire.requestFrom(0x40, 6);

Wire.requestFrom(address, quantity) asks the sensor to send data.

What function reads a single byte from the I2C data buffer?

A Wire.read()

B Wire.get()

C Wire.receive()

D Wire.fetch()

Wire.read() reads one byte from the incoming data.

Why is it important to know the I2C address of your sensor?

A To communicate with the correct device on the bus

B To power the sensor correctly

C To set the baud rate

D To configure the sensor's pins

The I2C address tells the Arduino which device to talk to among many on the bus.

Explain the basic steps to read data from an I2C sensor using Arduino.

Think about starting communication, asking for data, and reading it.

Why is the I2C protocol useful for connecting sensors to microcontrollers?

Consider how many wires and devices can share the same connection.