Every Bit needs an electrical signal running through it in order to work, and it gets this signal from through its input bitSnap. For Bits that have multiple input bitSnaps (like the codeBit or LED matrix), you can run wires to all of the Bits connected to its inputs….or you can just use some powerSnaps!
powerSnaps are especially helpful for building game controllers because then you only need one wire to connect the controller to the rest of your circuit.
HOW IT WORKS
To understand how a powerSnap works and why we need to use one, it’s helpful to look at how electricity works in a littleBits circuit.
Every bitSnap (including the powerSnap) has three gold colored pins on its face. When you put two bitSnaps together, the pins from one bitSnap connect with the pins from the other bitSnap, sending electricity between them. Why three pins? The two outside pins connect to the (+) and (-) lines that you always find in a circuit. That means the current flows out from the battery on the (+) line and returns back to the battery on the (-) line. These lines are arranged in what’s called a parallel circuit to make sure that every Bit in your circuit has power.
But just because a Bit has power doesn’t mean that it will be lighting up, moving, or making noise. That’s all up to the pin in the middle, the signal pin.
The power bit sends a 5 volt signal through the signal pin. This signal line runs through all the Bits in your circuit and is what tells output Bits what to do. If the signal is 5 volts, lights shine their brightest, motors turn their fastest, and buzzers buzz their loudest. Input Bits like dimmers do their thing by changing how much of this signal passes through them to the Bits that follow.
So how does the powerSnap work? Inside the powerSnap is a wire that connects the (+) pin and the signal pin. In the circuit below, the button can’t have any affect on the circuit because there is no signal coming in to turn on and off. But when we add the powerSnap, current moves into the powerSnap from the (+) line and into the signal line. This gives the button something to work with. The powerSnap can only do this though if there is current flowing on the (+) line, so there needs to be a power Bit snapped to your circuit somewhere