Let's identify the main sensors found in smartphones

(7–9 minutes)

When buying a new smartphone, you may have noticed a list of various sensors mentioned, usually in English. To understand whether these features are useful, it's important to know about them. If you're curious about how your smartphone has so many capabilities, this article is a good opportunity to learn.

Gyroscope

A gyroscope is a sensor that significantly enhances everyday smartphone usage, especially for tasks like taking panoramic and 360-degree photos. If you play car games, you've probably tilted your phone like a steering wheel without realizing that a gyroscope was helping detect the rotation. Essentially, it senses rotational movement even without shifting in space.

This sensor is also used in altimeters, which measure height above sea level, and in aircraft to indicate altitude and orientation. In movies, you may have seen fast-rotating meters in airplanes indicating emergency situations; that’s the gyroscope at work. In smartphones, it helps detect motion, ensuring your photos stay straight and reducing motion blur.

While traditional gyroscopes are large, the ones in smartphones are made using micro-electro-mechanical systems, making them compact enough to fit in slim phone designs. The technology gained widespread attention with the release of the iPhone 4 in 2010, enabling precise orientation detection for the first time.

Accelerometer

The accelerometer is common in fitness trackers and smartphones, helping detect acceleration along different axes. It can detect orientation and movement in three-dimensional space, similar to a gyroscope. Budget devices without gyroscopes often rely on this method.

However, acceleration-based measurements may be less reliable for certain tasks, such as playing car games on winding roads, because they assume gravity is always downward, which can cause inaccuracies. Nonetheless, the accelerometer allows step counting in fitness apps and tracks movement on maps like Google or Apple Maps. It’s also used in augmented reality apps like Pokémon Go, Google Translate, and Snapchat.

Smartphone accelerometers are constructed using tiny crystal elements. By measuring the voltage changes caused by the movement of these crystals, the phone can detect speed and direction. This is why your screen or video shifts to landscape mode when you rotate your phone.

Magnetometer

The magnetometer, or compass sensor, detects changes in the Earth's magnetic field and helps your phone identify the direction you are facing. It’s crucial for navigation apps like Google or Apple Maps. This sensor can also be used in apps that detect metal objects.

It works by detecting changes in voltage caused by magnetic forces. While your phone's magnetometer isn't strong enough to detect objects deep underground, it can still sense if a pencil on your desk contains metal.

GPS Sensor

The Global Positioning System (GPS) sensor uses satellite signals to determine your location without mobile data. This technology has made it incredibly easy to find your way, even in remote areas. It calculates your position based on signals from satellites overhead and displays it on map apps like Google Maps or Apple Maps.

However, GPS performance may degrade under thick cloud cover or indoors. In these cases, the phone can use cell towers or Wi-Fi signals to estimate your location, known as Assisted GPS (A-GPS). This service requires data but can locate you in just a few seconds.

GPS sensors consume more battery power due to their independent operation. That’s why many battery-saving apps recommend turning GPS off. Manufacturers are also hesitant to include GPS in small devices like smartwatches for this reason. Apps that display your vehicle’s speed, such as speedometer apps, also use GPS data for speed calculations.

Other Essential Sensors

• Proximity Sensor: When you receive a call and hold the phone to your ear, the screen turns off automatically. This happens because the proximity sensor uses infrared light to detect when the phone is covered. Some phones with flip covers also use this feature to turn the screen on or off.

• Ambient Light Sensor: Located near the front of the phone, this sensor automatically adjusts screen brightness based on the surrounding light levels, increasing it in bright sunlight and decreasing it in darkness.

In addition to these, some smartphones may include sensors like temperature, humidity, heart rate, or barometer sensors. 

2024-10-22   vishwa thilina