CapMeter — RC Charge-Time Capacitance Meter

About this project

CapMeter is a standalone capacitance meter built entirely from an Arduino Uno and two resistors — no dedicated capacitance-measuring IC required. It exploits the RC time-constant principle: the Arduino charges an unknown capacitor through a known 10 kΩ resistor and measures the time for the voltage to reach 63.2% of VCC (one time constant τ = RC). Since R is known precisely, C = τ/R. Results are displayed on a 16×2 I2C LCD in auto-ranging pF/nF/µF format. A push button triggers each measurement; a green LED signals ready and a red LED signals measuring. This project teaches RC circuit time constants, ADC threshold detection, high-resolution timing with micros(), and auto-ranging display logic — fundamental ECE instrumentation concepts.

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)