How to Throw a Signal Further than a Football

Over a few feet of wire, sending a signal isn’t hard. There isn’t usually any electrical noise that can interfere with your data over such a short run. The same goes with slow messages – computers are better at detecting long, slow data pulses through the electrical noise. However, once you get up to 20 or 30 feet of wire – or you’re trying to send a million bits of data per second – noise can be a problem. When you’re sending data in pulses, external electrical phenomenon, such as static discharge, can register as false data. One of the methods used to counteract this is known as differential signaling. It works by sending out two signals, instead of one, with a slight delay between the two. When sending data over a pair of wires that are twisted around each other, any electrical interference will occur at the same time in both wires. So, if we filter out any signals that occur in the wires simultaneously, we are left with only the original message. This is the basic principle of a signaling method known as “differential signaling.” This signaling method works both ways, and can also be used to send data back over a line. It allows two devices to communicate seamlessly, without the electrical noise that can make it difficult to send high speed messages. The most common way to interface with this protocol is through a MAX485 integrated circuit. It can connect to any standard microprocessor, and has the added benefit of protecting sensitive circuits from damage due to electrical noise. A common usage of this system is in ethernet connections and internet communications, as well as the stage lighting standard known as DMX. Using this signaling method will allow our (and your) projects to communicate over a much longer distance and expands the scope of what can be done with electronics!