⏱️ Timer/PWM Frequency Calculator

🎯 Getting Started

This calculator helps you configure microcontroller timers for precise frequency generation and PWM control.

• Clock Speed: Enter your microcontroller's timer clock frequency (e.g., 72MHz for STM32, 16MHz for Arduino)
• Target Frequency: Enter the desired output frequency (e.g., 50Hz for servos, 1kHz for PWM)
• Auto-Calculate: The tool finds optimal Prescaler and Period (ARR) values
• Code Generation: Get ready-to-use C code for timer initialization

📐 The Math Behind It

Basic Formula:

Frequency = Clock / ((Prescaler + 1) × (Period + 1))

• Clock: Timer input frequency (usually system clock or peripheral clock)
• Prescaler (PSC): Divides the clock before the counter (0-65535 for most MCUs)
• Period (ARR): Auto-Reload Register value, counter counts from 0 to this value (0-65535)

💡 Adding 1 to both values is because these are zero-indexed registers

⚙️ PWM & Duty Cycle

PWM Duty Cycle Formula:

Duty Cycle (%) = (Compare Value / Period) × 100

• Compare Value (CCR): When counter reaches this value, PWM output toggles
• 50% Duty: CCR = Period / 2
• Servo Control: Typically 1-2ms pulse width at 50Hz (5-10% duty cycle)

🔧 Common Use Cases

• Servo Motors: 50Hz signal, 1.5ms pulse (7.5% duty) for center position
• Motor Control: 1-20kHz PWM for DC motor speed control
• LED Dimming: 500Hz-2kHz PWM to avoid visible flicker
• Timing Events: 1Hz-1kHz for periodic interrupts

🎓 Optimization Tips

• Higher Period = Better Resolution: Use smaller prescaler and larger period for finer duty cycle control
• 16-bit Limit: Most timers have 16-bit registers (0-65535 max)
• Error Percentage: Watch the calculated error - lower is better
• Balanced Values: The calculator tries to balance PSC and ARR for optimal resolution