sizeof and memory budgeting in Embedded C - Mini Project: Build & Apply

Memory Budgeting with sizeof in Embedded C

📖 Scenario: You are working on a small embedded system with limited memory. You need to keep track of how much memory your variables use to avoid running out of space.

🎯 Goal: Build a simple program that calculates the total memory used by different variables using the sizeof operator.

📋 What You'll Learn

Create variables of different types

Use sizeof to find the size of each variable

Calculate the total memory used

Print the total memory size

💡 Why This Matters

🌍 Real World

Embedded systems often have very limited memory. Knowing how much memory your variables use helps you avoid crashes and bugs.

💼 Career

Embedded C programmers must manage memory carefully. Using <code>sizeof</code> helps estimate memory needs and optimize code.

1

Create variables of different types

Create three variables: an int called count, a char called flag, and a float called temperature.

Embedded C

# Create variables: int count, char flag, float temperature
// Your code here

Need a hint?

Use the syntax type name; to declare variables.

2

Create variables to hold sizes

Create three size_t variables called size_count, size_flag, and size_temperature to store the sizes of count, flag, and temperature respectively.

Embedded C

int count;
char flag;
float temperature;
// Create size_t variables: size_count, size_flag, size_temperature
// Your code here

Need a hint?

Use size_t to store sizes returned by sizeof.

3

Use sizeof to get sizes

Assign the size of count to size_count, the size of flag to size_flag, and the size of temperature to size_temperature using the sizeof operator.

Embedded C

int count;
char flag;
float temperature;
size_t size_count;
size_t size_flag;
size_t size_temperature;
// Assign sizes using sizeof
// Your code here

Need a hint?

Use sizeof(variable) to get the size in bytes.

4

Calculate and print total memory used

Create a size_t variable called total_size that sums size_count, size_flag, and size_temperature. Then print total_size using printf with the format specifier %zu.

Embedded C

int count;
char flag;
float temperature;
size_t size_count = sizeof(count);
size_t size_flag = sizeof(flag);
size_t size_temperature = sizeof(temperature);
// Calculate total_size and print it
// Your code here

Need a hint?

Use size_t total_size = size_count + size_flag + size_temperature; and printf("Total memory used: %zu bytes\n", total_size);.