FreqBlade — Digital Frequency & Duty Cycle Analyzer

About this project

FreqBlade is a handheld digital frequency and duty cycle analyzer that measures any digital signal from 1Hz to 100kHz using only a probe wire and Arduino's hardware interrupt. Touch the probe to a PWM motor controller, 555 timer output, Arduino pin, or any digital signal — FreqBlade displays the exact frequency (auto-formatted in Hz or kHz) and duty cycle percentage on a 16×2 LCD. A 5-LED bar graph shows duty cycle visually. A built-in 490Hz 50% test signal on D11 lets you verify the circuit in 10 seconds with just a jumper wire. No oscilloscope needed. This teaches hardware interrupts, micros() timing, and the relationship between frequency, period, and duty cycle — core ECE measurements every student needs.

What you get

• Complete, commented source code
• Full components list with quantities
• Pin-by-pin wiring guide and connection table
• Step-by-step upload and testing guide
• Project report (.docx, IEEE style)
• Presentation slides (.pptx)