Sensors in Mobile devices

Modern mobile phones come with a variety of sensors that automate or easy many of our daily tasks. This field takes into account the presence of an accelerometer, a gyroscope, a compass, and a barometer.

Accelerometer and gyroscope:-

Accelerometers in mobile phones are used to detect the orientation of the phone. The gyroscope, or gyro for short, adds an additional dimension to the information supplied by the accelerometer by tracking rotation or twist.

An accelerometer measures linear acceleration of movement, while a gyro on the other hand measures the angular rotational velocity. Both sensors measure rate of change; they just measure the rate of change for different things.

In practice, that means that an accelerometer will measure the directional movement of a device but will not be able to resolve its lateral orientation or tilt during that movement accurately unless a gyro is there to fill in that info.

With an accelerometer you can either get a really "noisy" info output that is responsive, or you can get a "clean" output that's sluggish. But when you combine the 3-axis accelerometer with a 3-axis gyro, you get an output that is both clean and responsive in the same time."

Application of Gyros:-

• Auto Balancing Robot
• Car navigation
• Mobile games
• Motion sensing
• Radio – controlled helicopters
• Motorboats
• Aircraft
• Space shuttle
• Digital and SLR camera

Digital compass:-

The digital compass that's usually based on a sensor called magnetometer provides mobile phones with a simple orientation in relation to the Earth's magnetic field. As a result, your phone always knows which way is North so it can auto rotate your digital maps depending on your physical orientation.

Barometer:-

Barometer as “a scientific instrument used in meteorology to measure atmospheric pressure.” It measures the pressure exerted by the atmosphere above it. This measurement of pressure can be used to forecast short term changes in the weather and can be used to estimate altitude.

Some manufacturer includes “clock and weather” widget prominently featured on the home screen. Other app developers have created similar widgets.

These widgets use your Smartphone’s Geo-location information and your Internet connection to retrieve local weather information (current, high, and low temperatures; and current conditions) for various weather data providers. Using the same information you can get the weather forecast for the next several days.

Note: - Barometer is there to help the GPS chip inside the device get a faster lock by instantly delivering altitude data.