Bluetooth 4.0 USB Module (v2.1 Back-Compatible) _MAKE_SENSOR_DISTANCE and there are way more

and there are way more tutorials at these fine sites:

Here's a sheet of Breadboard-Friendly NeoPixel breakouts fresh from the (reflow) oven

Fitted with UK plug

below 300mA

a plug-and-play heart-rate sensor for Arduino and Arduino compatibles

Bluetooth 4.0 USB Module (v2.1 Back-Compatible) _MAKE_SENSOR_DISTANCE and there are way moreThe Xinghuatian Tech Bluetooth 4. 0 USB Module adds Bluetooth Low Energy support to your computer via USB, using a CSR8510 chipset and working with built in drivers on most modern systems. Add Bluetooth capability to your computer super fast with a Xinghuatian Tech Bluetooth 4. 0 USB Module. This adapter is backwards compatible with v2. 1 and earlier, but also supports the latest v4. 0 Bluetooth Low Energy. Inside lies a CSR8510 Bluetooth USB host.