Wake-up sources configuration in Embedded C - Mini Project: Build & Apply

Wake-up Sources Configuration

📖 Scenario: You are working on a small embedded system that can wake up from sleep mode using different sources like a timer, a button press, or a sensor signal.To save power, the system should only wake up from the sources you enable.

🎯 Goal: You will write a simple program to configure which wake-up sources are enabled using a bitmask variable.This will help the system know which events should wake it up.

📋 What You'll Learn

Create a variable to hold the wake-up sources configuration.

Define constants for each wake-up source using bit flags.

Set a configuration variable to enable specific wake-up sources using bitwise OR.

Print the final configuration value.

💡 Why This Matters

🌍 Real World

Embedded devices often need to save power by sleeping and waking only on certain events. Configuring wake-up sources correctly is essential for battery life and responsiveness.

💼 Career

Understanding bitwise operations and hardware configuration is key for embedded systems engineers and firmware developers working on low-power devices.

1

Define wake-up source constants

Define three constants called WAKEUP_TIMER, WAKEUP_BUTTON, and WAKEUP_SENSOR with values 0x01, 0x02, and 0x04 respectively.

Embedded C

// Define wake-up source constants here
// Your code here

Need a hint?

Use #define to create constants with the exact names and values.

2

Create wake-up configuration variable

Create an unsigned char variable called wakeup_config and initialize it to zero.

Embedded C

#include 

#define WAKEUP_TIMER 0x01
#define WAKEUP_BUTTON 0x02
#define WAKEUP_SENSOR 0x04

// Create wakeup_config variable and set to 0
// Your code here

Need a hint?

Use unsigned char wakeup_config = 0; to create the variable.

3

Enable timer and button wake-up sources

Set wakeup_config to enable both WAKEUP_TIMER and WAKEUP_BUTTON using the bitwise OR operator.

Embedded C

#include 

#define WAKEUP_TIMER 0x01
#define WAKEUP_BUTTON 0x02
#define WAKEUP_SENSOR 0x04

unsigned char wakeup_config = 0;

// Enable WAKEUP_TIMER and WAKEUP_BUTTON in wakeup_config
// Your code here

Need a hint?

Use | to combine the flags.

4

Print the wake-up configuration

Write a printf statement to print the value of wakeup_config as a hexadecimal number with 0x prefix.

Embedded C

#include 

#define WAKEUP_TIMER 0x01
#define WAKEUP_BUTTON 0x02
#define WAKEUP_SENSOR 0x04

unsigned char wakeup_config = 0;

wakeup_config = WAKEUP_TIMER | WAKEUP_BUTTON;

// Print wakeup_config in hex format
// Your code here

Need a hint?

Use printf("Wake-up configuration: 0x%02X\n", wakeup_config); to print the value.