Input
What is put "in" to tell a circuit what to do. This could be a switch or a sound that triggers the circuit on or off, etc. Here are some LittleBits "input" modules:
Switch
There is a switch on the power module. When a switch is on, it completes the electrical circuit. When the switch is "off", it breaks the electrical circuit. Click on each image to enlarge it.
Slide Dimmer
By moving the slider from one end to the other you go gradually from low (or off) to high intensity. This is how a light dimmer or recording studio volume fader works.
Pulse
The pulse module is like an electronic switch that turns on and off continuously. This is how flashing Christmas lights, strobe flashlight, or the turn signal in a car works.
Pressure Sensor
The pressure sensor allows you to control things by apply more or less pressure on the sensor. The more pressure you apply, the more current this module lets out. The iPhone 6S 3D touch works on sensing pressure.
Sound Trigger
Roller Switch