I’ll show you how to drop an Arduino into a cheap speaker ... dangerous if mistreated. Once the circuit board has been extracted, the Bluetooth interface module should immediately stand out ...

[AlxDroidDev’s] device runs off of an ATMega328p with Arduino. It operates from a 9V battery. The circuit contains an infrared receiver and also a Bluetooth module. This allows [AlxDroidDev] to ...

Then, an Arduino board might be ... protocols like Wi-Fi and Bluetooth, though. However, additional components -- a Wi-Fi shield and a Bluetooth module -- are required. The R4 WiFi is already ...