and the weight of it activates a hidden switch, which causes the sculpture to display its secret LEDs. [MakeFunStuff] wanted to make something that looked less like a circuit and more like art ...

Here is a simple general-purpose security alarm circuit built on the Arduino ... and hence the reed switch should be in “closed”state at standby mode. When reed switch is opened, pin 2 of Arduino goes ...

The limit switch pairs go in the square loops in the diagram (one shown open circuit = triggered) D1, 2 and 3 are the internal opto-isolator leds, and the opto-isolator output transistors (not shown) ...

In normally closed reed switch, switch is closed in the absence of magnetic field and it is open in the presence of magnetic field. The complete code for this Arduino reed switch project is given at ...

You don't HAVE to switch off the Arduino itself - you can use this same circuit to just switch off everything else instead and then put the Arduino into Deep Sleep. We cover this in the video too! Now ...

So tilt sensor can turn on or off the circuit based on the orientation. In this project, we are interfacing Mercury switch ... at PIN 4 of the Arduino. LED is connected with the PIN 2 of the Arduino ...

Due to the small power consumption, the panel is simply powered by the 5Vcc of the USB connection and basically the only limit of the number of status LEDs and command buttons/switches is the number ...