Why I2C is used in Embedded C - See It in Action

Why I2C is used

📖 Scenario: You are working on a small embedded system that needs to communicate with multiple sensors and devices using only a few wires.

🎯 Goal: Understand why the I2C communication protocol is used by creating a simple program that sets up device addresses and demonstrates communication over I2C.

📋 What You'll Learn

Create a list of device addresses connected to the I2C bus

Set a variable for the maximum number of devices allowed on the bus

Write a loop to check which devices are connected by comparing addresses

Print the addresses of connected devices

💡 Why This Matters

🌍 Real World

I2C is used in embedded systems to connect sensors, displays, and other components with minimal wiring.

💼 Career

Understanding I2C helps in designing efficient hardware communication for microcontrollers and embedded devices.

1

Create a list of I2C device addresses

Create an array called device_addresses with these exact values: 0x3C, 0x27, 0x68, 0x40.

Embedded C

# Create an array called device_addresses with the given I2C addresses
// Your code here

Need a hint?

Use curly braces to list the addresses inside the array.

2

Set the maximum number of devices

Create an integer variable called max_devices and set it to 4.

Embedded C

unsigned char device_addresses[] = {0x3C, 0x27, 0x68, 0x40};
// Create an int variable max_devices and set it to 4
// Your code here

Need a hint?

Use int to declare the variable and assign the value 4.

3

Check connected devices using a loop

Write a for loop using int i from 0 to less than max_devices. Inside the loop, create an if statement that checks if device_addresses[i] is not zero. If true, call a function check_device(device_addresses[i]).

Embedded C

unsigned char device_addresses[] = {0x3C, 0x27, 0x68, 0x40};
int max_devices = 4;
// Loop through device_addresses and call check_device for each non-zero address
// Your code here

Need a hint?

Use a for loop with i from 0 to max_devices - 1. Inside, use if to check the address and call the function.

4

Print connected device addresses

Write a for loop using int i from 0 to less than max_devices. Inside the loop, print the text "Device found at address: 0x" followed by the hexadecimal value of device_addresses[i] using printf.

Embedded C

unsigned char device_addresses[] = {0x3C, 0x27, 0x68, 0x40};
int max_devices = 4;

for (int i = 0; i < max_devices; i++) {
    if (device_addresses[i] != 0) {
        check_device(device_addresses[i]);
    }
}
// Print each device address in hex format
// Your code here

Need a hint?

Use printf("Device found at address: 0x%X\n", device_addresses[i]); inside the loop.