Writing data to I2C device in Embedded C - Mini Project: Build & Apply

Writing data to I2C device

📖 Scenario: You are working on a small embedded system that communicates with a sensor using the I2C protocol. To control the sensor, you need to send specific data bytes to it over the I2C bus.

🎯 Goal: Build a simple program that writes a sequence of bytes to an I2C device using a basic I2C write function.

📋 What You'll Learn

Create an array of bytes to send to the I2C device

Define the I2C device address as a variable

Use a function call to write the data array to the I2C device

Print a confirmation message after writing the data

💡 Why This Matters

🌍 Real World

Embedded systems often communicate with sensors and other devices using I2C. Writing data correctly is essential for controlling hardware.

💼 Career

Understanding I2C communication is important for embedded software engineers working on hardware interfacing and device drivers.

1

Create the data array

Create a byte array called data_to_send with these exact values: 0x10, 0x20, 0x30, 0x40.

Embedded C

# Create the byte array data_to_send with the specified values
// Your code here

Need a hint?

Use curly braces to list the bytes inside the array.

2

Define the I2C device address

Create an unsigned char variable called device_address and set it to 0x50.

Embedded C

unsigned char data_to_send[] = {0x10, 0x20, 0x30, 0x40};
// Define the device_address variable with value 0x50
// Your code here

Need a hint?

Use the exact variable name device_address and assign the hex value 0x50.

3

Write data to the I2C device

Call the function i2c_write with these arguments in order: device_address, data_to_send, and the length 4.

Embedded C

unsigned char data_to_send[] = {0x10, 0x20, 0x30, 0x40};
unsigned char device_address = 0x50;
// Call i2c_write with device_address, data_to_send, and length 4
// Your code here

Need a hint?

Store the return value of i2c_write in a variable called result.

4

Print confirmation message

Use printf to print exactly this message: "Data written to device 0x50\n".

Embedded C

unsigned char data_to_send[] = {0x10, 0x20, 0x30, 0x40};
unsigned char device_address = 0x50;

int result = i2c_write(device_address, data_to_send, 4);
// Print confirmation message
// Your code here

Need a hint?

Use printf with the exact string including newline \n.