The "Safe Box" project is a handmade cardboard box system featuring a keypad, LCD screen, white LED, blue LED, and a buzzer. When powered on, the LCD prompts the user to enter a secret code. The ...

Planning a game of Hacker Jeopardy at your next meetup? You’re going to want some proper buzzers to complete the experience, but why buy when you can build? [Flute Systems] has released an open source ...

Troubleshooting Buzzer is ON constantly / inverted behavior → Set #define BUZZER_ACTIVE_LOW 1 (active-LOW) or 0 (active-HIGH). → Ensure the buzzer I/O is on GPIO18, not tied to 3V3. Boot chirp (buzz ...