Why dynamic memory is risky in embedded in Embedded C - See It in Action

Why Dynamic Memory is Risky in Embedded Systems

📖 Scenario: You are working on a small embedded device that controls a home appliance. Memory is very limited and must be managed carefully.

🎯 Goal: Understand why using dynamic memory (like malloc and free) can be risky in embedded systems by simulating a simple memory allocation scenario.

📋 What You'll Learn

Create a fixed-size array to simulate memory

Create a variable to track allocated memory size

Write code to simulate allocating memory dynamically

Print the current allocated memory size

💡 Why This Matters

🌍 Real World

Embedded devices often have very limited memory and no operating system to manage it. Careful memory management is critical to avoid crashes.

💼 Career

Embedded software engineers must understand memory risks to write reliable code for devices like sensors, appliances, and controllers.

1

Create a fixed-size memory array

Create a fixed-size array called memory_pool of 100 bytes to simulate available memory.

Embedded C

char memory_pool[100];  // Your code here

Need a hint?

Use char memory_pool[100]; to create an array of 100 bytes.

2

Create a variable to track allocated memory

Create an integer variable called allocated_size and set it to 0 to track how much memory is allocated.

Embedded C

char memory_pool[100];
int allocated_size = 0;  // Your code here

Need a hint?

Use int allocated_size = 0; to start with no memory allocated.

3

Simulate allocating memory

Write code to simulate allocating 20 bytes by adding 20 to allocated_size. Use an if statement to check if allocated_size + 20 is less than or equal to 100 before adding.

Embedded C

char memory_pool[100];
int allocated_size = 0;

// Your code here to allocate 20 bytes safely

Need a hint?

Check if adding 20 bytes fits in memory before increasing allocated_size.

4

Print the allocated memory size

Write a printf statement to print the current allocated_size with the message: "Allocated memory: %d bytes\n".

Embedded C

char memory_pool[100];
int allocated_size = 0;

if (allocated_size + 20 <= 100) {
    allocated_size += 20;
}

// Your code here to print allocated_size

Need a hint?

Use printf("Allocated memory: %d bytes\n", allocated_size); inside main().