HC-05 Bluetooth Module (with AT Button)

HC-05 is a Bluetooth 2.0+EDR serial transceiver module (CSR BC417 chipset)—acts as UART pipe (3.3V logic, 5V tolerant) for wireless Arduino/PC links up to 10m (Class 2). Great for first-year engineering students' remote control or sensor streaming projects.

Default slave; AT mode (KEY high, 38400 baud) for config (name/PIN/role/baud 1200–1382400); LED states (fast flash unpaired, slow AT, double paired).