In this quick Arduino ... can use this code example to introduce a delay in your circuit. The variable “stayON” is used to delay() the program execution with the desired amount of time. In our case ...

Her code allows you to configure the type and number of RFID cards required to trigger one of the Arduino’s digital pins, which usually would be connected to a relay to fire off whatever device ...

It’s a fairly simple project, too: just hook an Arduino ... the power relay on top of the enclosure, ready to use with your fan or whatever appliance you’re looking to trigger.

Why not create your very own high-speed camera trigger using an Arduino, piezoelectric sensor (as a sound sensor), a DSLR camera, and an external flash. Watch the video after the break to see it ...