Timer prescaler and clock division in Embedded C - Mini Project: Build & Apply

Timer Prescaler and Clock Division

📖 Scenario: You are working with a microcontroller timer that counts pulses from a clock source. To control the timer speed, you use a prescaler that divides the clock frequency.Understanding how to set the prescaler and calculate the timer tick frequency is important for timing tasks like blinking an LED or measuring intervals.

🎯 Goal: Build a simple program that sets a timer prescaler and calculates the timer tick frequency based on the system clock and prescaler value.

📋 What You'll Learn

Create a variable for the system clock frequency in Hz

Create a variable for the timer prescaler value

Calculate the timer tick frequency by dividing the system clock by the prescaler

Print the timer tick frequency

💡 Why This Matters

🌍 Real World

Microcontrollers use timers with prescalers to create precise delays and measure time intervals in embedded systems like blinking LEDs, motor control, or communication protocols.

💼 Career

Understanding timer prescalers and clock division is essential for embedded software engineers working on hardware control, real-time systems, and device drivers.

1

Set the system clock frequency

Create an unsigned int variable called system_clock_hz and set it to 16000000 (16 MHz).

Embedded C

# Create an unsigned int variable called system_clock_hz and set it to 16000000
// Your code here

Need a hint?

The system clock frequency is usually given in Hertz (Hz). 16 MHz means 16 million cycles per second.

2

Set the timer prescaler value

Create an unsigned int variable called prescaler and set it to 64.

Embedded C

unsigned int system_clock_hz = 16000000;
// Create an unsigned int variable called prescaler and set it to 64
// Your code here

Need a hint?

The prescaler divides the system clock frequency to slow down the timer.

3

Calculate the timer tick frequency

Create an unsigned int variable called timer_tick_hz and set it to the result of dividing system_clock_hz by prescaler.

Embedded C

unsigned int system_clock_hz = 16000000;
unsigned int prescaler = 64;
// Calculate timer_tick_hz by dividing system_clock_hz by prescaler
// Your code here

Need a hint?

Use the division operator / to calculate the timer tick frequency.

4

Print the timer tick frequency

Use printf to print the text "Timer tick frequency: " followed by the value of timer_tick_hz and then a newline.

Embedded C

unsigned int system_clock_hz = 16000000;
unsigned int prescaler = 64;
unsigned int timer_tick_hz = system_clock_hz / prescaler;
// Print the timer tick frequency
// Your code here

Need a hint?

Use printf("Timer tick frequency: %u\n", timer_tick_hz); inside main().