littleBits NAND

The NAND Bit is a logic gate with two inputs and one output. NAND is short for NOT AND which is the combination of an AND gate where the output is inverted. The NAND only outputs an OFF signal when both of the inputs are ON, or true. If both inputs are OFF, the output signal will be ON. Building circuits with logic Bits is essentially the equivalent of physical prograqmming. Logic Bits create rules for your circuit to follow, giving you more ability to create interesting and complex interactions.

Anytime the NAND receives a signal lower than 2.5 volts at either of its inputs, the NAND sends an ON signal of 5 volts from its output. If the NAND receives a signal greater than 2.5 volts at either of its inputs, the NAND sends an ON signal of 5 volts from its output. If the NAND receives a signal greater than 2.5 volts at both of its inputs at the same time, the NAND sends an OFF signal of 0 volts from its output. Logic Bits like the NAND Bit only work with two states of inputs, ON and OFF. When an input is either ON or OFF, like a button, a toggle switch, or a sound trigger, we call it a digital input. Inputs that have variable voltage like pressure sensors, dimmers, and light sensors, are analog inputs. Because logic gates only deal with ON/OFF, high/low, or true/false, analog signals pass as digital. With analog inputs, an “ON” signal occurs at about 2.5 volts when passing through a logic gate. Also in logic circuits, you may want to hold the state of a momentary input (like a button). In order to hold this state, you can use a latch. You can also use a timeout to hold the state for a certain period of time.