UART protocol fundamentals in Embedded C - Mini Project: Build & Apply

UART Protocol Fundamentals

📖 Scenario: You are working on a small embedded system that communicates with a sensor using UART (Universal Asynchronous Receiver/Transmitter). You need to set up the UART data buffer and process the data bytes received.

🎯 Goal: Build a simple UART data handler in C that stores received bytes in a buffer, counts how many bytes are received, and prints the buffer content.

📋 What You'll Learn

Create a buffer array to hold UART data bytes

Create a variable to count the number of bytes received

Use a loop to simulate receiving bytes and store them in the buffer

Print the received bytes as hexadecimal values

💡 Why This Matters

🌍 Real World

Embedded systems often use UART to communicate with sensors, modules, or other microcontrollers. Handling UART data buffers is essential for reliable data exchange.

💼 Career

Understanding UART protocol basics is important for embedded software developers working on hardware communication, device drivers, or IoT devices.

1

Create UART data buffer

Create an array called uart_buffer of type unsigned char with size 5 to hold UART data bytes.

Embedded C

# Create an array called uart_buffer of unsigned char with size 5
// Your code here

Need a hint?

Think of uart_buffer as a small box that can hold 5 bytes of data.

2

Create byte count variable

Create an integer variable called byte_count and initialize it to 0 to count how many bytes are received.

Embedded C

unsigned char uart_buffer[5];
// Create an integer variable byte_count and set it to 0
// Your code here

Need a hint?

This variable will keep track of how many bytes you have stored in the buffer.

3

Store received bytes in buffer

Use a for loop with variable i from 0 to 4 to simulate receiving bytes. Store the values 0x10 + i into uart_buffer[i]. After storing each byte, increase byte_count by 1.

Embedded C

unsigned char uart_buffer[5];
int byte_count = 0;
// Use a for loop with i from 0 to 4 to store bytes 0x10+i into uart_buffer[i]
// Increase byte_count by 1 each time
// Your code here

Need a hint?

Imagine you receive bytes 0x10, 0x11, 0x12, 0x13, 0x14 one by one and store them in the buffer.

4

Print received UART bytes

Use a for loop with variable i from 0 to byte_count - 1 to print each byte in uart_buffer as hexadecimal using printf with format "0x%02X ". After the loop, print a newline.

Embedded C

unsigned char uart_buffer[5];
int byte_count = 0;

for (int i = 0; i < 5; i++) {
    uart_buffer[i] = 0x10 + i;
    byte_count++;
}

// Print each byte in uart_buffer as hex with printf
// Your code here

Need a hint?

This will show the bytes you stored, like reading the data from the UART line.