littleBits NAND

A NAND bit is a logic gate with two inputs and one output. NAND is short for NOT AND, which is a combination of an AND gate where the output is inverted. The NAND only outputs an OFF signal when both inputs are ON or true. If both inputs are OFF, the output signal is ON. Building circuits using logic bits is essentially equivalent to physical programming. Logic Bits creates rules that your circuit must follow, giving you more opportunities to create interesting and complex interactions.

Whenever the NAND receives a signal below 2.5 volts at either of its inputs, the NAND sends a 5 volt ON signal from its output. If the NAND receives a signal greater than 2.5 volts at either of its inputs, the NAND sends a 5 volt ON signal from its output. If the NAND receives a signal greater than 2.5 volts from both of its inputs simultaneously, the NAND sends a 0-volt OFF signal from its output. Logic bits, such as a NAND bit, operate in only two input states, ON and OFF. When an input is either ON or OFF, such as a button, toggle switch, or audio trigger, we call it a digital input. Inputs with a variable voltage, such as pressure sensors, dimmers, and light sensors, are analog inputs. Since logic gates only handle ON/OFF, high/low, or true/false, analog signals travel as digital. For analog inputs, the "ON" signal occurs at about 2.5 volts as it passes through the logic gate. Also in logic circuits you may want to hold the state of a momentary input (like a button). To preserve this state, you can use a latch. You can also use a timeout to hold the state for a certain amount of time.