Magnetic RPM Counter

About this project

MagPulse is a two-mode instrument built on the A3144 Hall effect sensor — one of the most widely used sensors in industrial motors, speedometers, and position encoders. In PROXIMITY mode, it acts as a contactless magnetic alarm: wave any magnet near the sensor and MagPulse fires a buzzer, flashes LEDs, and shows MAGNET DETECTED on the LCD — useful for detecting hidden magnets inside objects without touching them. Switch to RPM mode, stick a small neodymium magnet on any spinning shaft (DC motor, fan, wheel), point MagPulse at it, and the LCD displays the exact RPM in real time, updated every second. A 5-LED bar graph visualises speed from Stopped to High Speed. A push button toggles between modes. This project teaches digital Hall sensing, interrupt-driven pulse counting, RPM calculation from pulse frequency, and the real-world connection between speed sensors and motor control.

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)