The device he holds in his hand is an Arduino connected to the OUTSIDE ... Apparently the DC barrel jack on the outside of the lock serves as a one-wire protocol interface. Once communications ...

Then, an Arduino board might be exactly what you ... Behind the R4 WiFi's barrel jack is a set of three headers labeled OFF, GND, and VRTC. The OFF pin is designed to turn off the board when ...

Comparing the Arduino Uno and the Nano, you'll notice that the former includes an onboard DC barrel jack where you can conveniently connect your supply. Because of the Nano's small form factor ...

The first published proof of concept used an Arduino board and a simple adapter ... the felt tip has been replaced with the appropriately sized barrel jack. Check out the ultra-fast and ...