This document provides an outline for the design and development of an optical particle counter unit. It describes the circuit design which implements a current-to-voltage converter and active high-pass filter to detect light scattered by particles. The circuit outputs voltage data to an Arduino where it is recorded to an SD card and transmitted via Bluetooth. The application is intended to allow real-time data transfer and Bluetooth connection functionality, which has been completed for turning on Bluetooth, making the device discoverable, and viewing paired devices. Further work remains on sending and receiving data and disabling the Bluetooth connection.