but plenty for an Arduino Nano. So far functionality for three of the four buttons on this speaker has been preserved: power, volume up, and volume down. The fourth button initiates Bluetooth ...

Arduino boards get a Bluetooth Smart dev kit from Nordic Semiconductor. The SDK is compatible with a range of Arduino, ChipKIT shields that employ the nRF8001 Bluetooth Smart connectivity device.

In final form, a Bluetooth module and Arduino Pro Micro are stuffed inside the stereo along with a DPDT relay to switch the I2C bus. An external button is used to trigger the Arduino to switch to ...