SciTech

Wireless mice use radio wave technology

Credit: Maegha Singh/ Credit: Maegha Singh/

Computer mice, named so for their scurrying movements, are the most interactive features of modern-day computers. Wireless mice, in particular, allow us an ease of motion and use that wired technology just doesn’t allow. In this day and age, we have become so accustomed to moving mice about our desks that we often don’t think of the technology that goes into making this process a reality.

Wireless mice have two components: a transmitter and a receiver. The transmitter is housed within the mouse itself, and the receiver plugs into the computer with which the mouse is interacting. Transmitters encode the mouse’s movements as radio wave signals and transmit them to the receiver, that decodes the movement information into a form which the computer can read and respond to.

There are two main transmitters used in computer mice: a rubber ball transmitter and an LED transmitter. The rubber ball mechanism is outdated, as of now. The rubber ball mouse has a rubber ball, similar to those found in mall vending machines, sticking out of its stomach. Within the mouse, next to the ball, are two vertical, plastic wheels with holes cut at intervals along the sides. These plastic wheels correspond to directional axes, so there is one which measures horizontal movement and one for vertical movement. As you move the mouse, the rubber ball rolls and causes either one or both of these plastic wheels to turn.

Depending on how far the mouse is moved, the wheel will turn a number of times. Each time the wheel turns, it interrupts a little beam of light within the mouse, and each interruption of this beam corresponds to a certain distance the mouse has been moved. This is how the computer translates the mouse’s physical movement into movement of the cursor on the screen. For Bluetooth systems, the most common mouse technology, the transmitter is a Bluetooth radio which allows the two devices to connect the mouse to a Bluetooth-enabled transceiver, like a computer.

Newer mice use a Light-Emitting Diode (LED) mechanism, whose movement is far more fluid. Instead of a ball projecting from its belly, the LED mouse shines a bright light onto the surface upon which it’s being used. This light is then reflected from the surface and back into the mouse. A chip within the mouse receives this reflected light and translates it into movement data.

The way an LED mouse measures its movement is by relating the mouse’s speed and distance traveled to the beam of light and the way it reflects back into the mouse. The movement data is then transmitted to the receiver attached to the computer and decoded in order to move the cursor.

The receiver is a bit of hardware connected to the computer and paired with the mouse so it can receive the radio frequencies being transmitted by the mouse. Pairing the two devices means making sure that they operate at the same radio frequency, and in doing so, cuts out interference from other radio communications and makes the connection safer and more reliable. In terms of security, some brands encrypt the mouse’s movement data or use frequency-jumping techniques to lessen the chance of interference from outside tampering — because really, what’s scarier than a rogue mouse?

There are many benefits to the use of radio technology for wireless mice, such as inexpensive and lightweight components, and a low power consumption. Radio waves, in comparison with the infrared technology used in remote controls, can also pass through obstacles such as a desk, so they add versatility in addition to ease of use.

While they may seem only a minor detail of one’s computer interface, a mouse is essentially a user’s right hand in many of his interactions with computers. Ensuring that it works, and works effortlessly, is a matter of good design and smart technology, and the more lightweight, accurate, and effortless mice become, the more effortless our interactions with computers will become.