He reads the square wave coming off of his tachometer input and pulses from a reed switch mounted on the wheel to calculate all this. To top it all off he can monitor the data via a Bluetooth ...

Based on a Nordic Semiconductor 32-bit ARM system-on-chip that has built-in support for Bluetooth 4.0, the RFduino runs the same code as Arduino UNO ... proximity-switch devices such as alarms ...

It can be used to control a number of GE-branded Bluetooth devices, like its Smart Bulbs and indoor and outdoor plugs. The system doesn't require a hub, and Avi-on claims the switch's battery will ...

This remote switch uses a sg90 servo, an Arduino Uno, and pairs of ATtiny85s with HC-05 Bluetooth modules assembled on protoboards. The 3D printed mount screws easily on top of a standard light ...

The Switcheroo is small enough to fit just about anywhere The first tool is the Switcheroo, a tiny Bluetooth circuit ... their own [NFC reader] with an Arduino and 3rd party reader device ...