Bluetooth Messaging System

Built a wireless messaging device using an Arduino and HC-05 Bluetooth module. Pairs with a smartphone for two-way texting. Implemented multi-tap text entry on a keypad, old-school phone style, with messages displaying on a 16x2 LCD.

Simple idea, surprisingly tricky execution. Debouncing the keypad, timing the multi-tap windows, and keeping the Bluetooth connection stable all at once. Good intro to real-time constraints.