Ring buffer implementation in Embedded C - Mini Project: Build & Apply

Ring buffer implementation

📖 Scenario: You are working on a small embedded system that needs to store sensor readings temporarily. To do this efficiently, you will use a ring buffer (also called a circular buffer). This buffer will hold a fixed number of readings and overwrite the oldest data when full.

🎯 Goal: Build a simple ring buffer in C that can store integer sensor readings. You will create the buffer, set its size, add new readings, and print the buffer contents.

📋 What You'll Learn

Create an integer array called buffer with size 5

Create integer variables head and tail to track positions

Create an integer variable buffer_size set to 5

Write a function add_to_buffer that adds a new integer to the buffer and updates head and tail correctly

Write a function print_buffer that prints all current values in the buffer from tail to head

Demonstrate adding 7 readings and printing the buffer contents

💡 Why This Matters

🌍 Real World

Ring buffers are used in embedded devices to store sensor data, communication bytes, or audio samples temporarily without delays.

💼 Career

Understanding ring buffers is important for embedded software engineers working on real-time systems, device drivers, or communication protocols.

1

Create the ring buffer data structure

Create an integer array called buffer with size 5. Also create integer variables head and tail and set both to 0.

Embedded C

# Create the buffer array and position variables
// Your code here

Need a hint?

Think of buffer as a fixed-size box to hold numbers. head and tail tell you where to add or remove data.

2

Add buffer size configuration

Create an integer variable called buffer_size and set it to 5.

Embedded C

int buffer[5];
int head = 0;
int tail = 0;
// Set the buffer size
// Your code here

Need a hint?

This variable helps us know the size of the buffer for wrapping around.

3

Write the function to add data to the buffer

Write a function called add_to_buffer that takes an integer value. It should store value at buffer[head], then increment head by 1 modulo buffer_size. If head equals tail after increment, also increment tail by 1 modulo buffer_size to overwrite oldest data.

Embedded C

int buffer[5];
int head = 0;
int tail = 0;
int buffer_size = 5;

// Write add_to_buffer function below
// Your code here

Need a hint?

Remember to wrap head and tail using modulo to stay inside the buffer size.

4

Print the buffer contents

Write a function called print_buffer that prints all values currently in the buffer from tail to head. Then add 7 values (1 to 7) to the buffer using add_to_buffer and call print_buffer to display the buffer contents.

Embedded C

int buffer[5];
int head = 0;
int tail = 0;
int buffer_size = 5;

void add_to_buffer(int value) {
    buffer[head] = value;
    head = (head + 1) % buffer_size;
    if (head == tail) {
        tail = (tail + 1) % buffer_size;
    }
}

// Write print_buffer function and add values below
// Your code here

Need a hint?

Use a loop starting from tail and stop before head. Use modulo to wrap around.