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All the Smartphone Sensors (and What they Do)

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Writer, Smart Home

For years technology has been a big part of Gardy's life. He's an Android guy with a secret love for Apple products. When not at work, you can usually catch him drawing with a pencil. He is a writer at Gotechtor covering streaming media, TVs, and everything smart-home related. 

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Have you ever wondered how smartphones manage all of the things they are capable of handling? How does your phone detect everything from motion, ambient lighting, temperature, humidity, proximity, phone positioning, etc?

All of this is made possible through the help of sensors. In this article, you’ll learn about all the smartphone sensors and what they do.

Smartphone Sensors and Their Uses

Before we go into details, you might be wondering what a smartphone sensor is. To put it simple, a smartphone sensor is a device installed on a phone that measures physical input in the nearby environment and converts it into data that users can interpret.

This list below includes all the standard sensors that are embedded in smartphones.

  • Accelerometer
  • Gyroscope
  • Magnetometer
  • Global Positioning System (GPS)
  • Proximity Sensor
  • Ambient Light Sensor
  • Microphone
  • Touchscreen Sensors
  • Fingerprint Sensor
  • Pedometer
  • Barcode/QR Code Sensors
  • Barometer
  • Heart Rate Sensor
  • Thermometer
  • Air Humidity Sensor
  • Geiger Counter
  • Soli sensor


As its name suggests, the accelerometer measures acceleration. It is with this sensor that your phone is able to detect your steps on pedometer apps and recognizes whether you are moving or not.

Its utilization of its features relies on axis-based motion sensing, which is how your phone recognizes whether it is facing upwards or downwards, as well as whether it’s in landscape or portrait mode. 

If you have ever turned your phone on its side and your screen rotator feature flipped the image so that it was still right-side-up, you have seen the accelerometer in action.

When the tiny sensors that make up the accelerometer stress due to motion, they respond by interpreting the level of stress to how fast they are moving. It is the accelerometer that allows your GPS app to inform you of how fast you are moving.


The gyroscope picks up motion-sensing where the accelerometer leaves off. Gyroscopes are not new. They have been long used in planes to detect altitude (as opposed to lateral motion), but in phones, they are now so common, we likely don’t think much about their presence.

When you play a game that allows you to shift your view or influence your action by simply tilting your phone to the side, you are making use of the gyroscope which interprets your small shifts and turns relative to prior phone positions, even though you are not physically moving in any direction.


While the gyroscope mainly operates on the phone’s physical orientation and the accelerometer measures motion, the magnetometer measures the direction and global positioning based on sensing of magnetic fields.

The magnetometer, for instance, works in tandem with the GPS sensor to turn the map in a particular direction when you are using the Apple Maps or Google Maps apps. 

In essence, this sensor is the main reason your phone can pinpoint your location relative to other places, allowing for detailed directions to be provided in navigational apps.

And yes, if you are wondering if this sensor can actually detect the magnetic properties of metals, it most certainly can. It has long been used in metal detectors and is made use of in metal detector apps as well.

Global Positioning System (GPS)

While the magnetometer assists in the magnetic location aspects, the GPS sensor is the main driver for your phone recognizing your global position.

The GPS pings space satellites without the need to use the phone’s data. If you have ever noticed that your phone is aware of where you are positioned even when you have no signal, that is why.

However, the GPS connectivity is draining to your phone’s battery, as the GPS sensor is perpetually seeking to connect to satellites. This is why turning the GPS off is one of the primary suggestions among battery-saving tips for smartphones. 

Check this out: 20 Tricks and Tips to Get the Most Out of Google Maps

Proximity Sensor

The proximity sensor determines how far objects are from the phone. For instance, a caller using a phone held up to their ear has the screen go dark when the phone is touching their face.

If the object is too close and the screen is on, it can trigger unintended actions to be taken by the user contacting the touchscreen. The proximity sensor determines that a user’s face is close enough to their screen, and proceeds to shut the screen off. 

Ambient Light Sensor

If you have ever noticed that the brightness on your phone auto-adjusts based on the lighting of the environment you are in, you have witnessed the ambient light sensor at work.

This sensor detects light around you, then communicates that information back to the phone’s OS, which in turn turns the brightness up or down, depending on the lighting situation.


The microphone is a sensor meant specifically for the detection of sound and volume of the sound. As the sound waves trigger the microphone sensor, the phone responds accordingly.

In the most traditional sense, it registers the sound to communicate for phone calls. In other respects, it is also utilized in voice search commands, spoken text dictation, and recognition of incoming sounds for identification, such as the one used by music identifier apps like Shazam.

Touchscreen Sensors

There is a constant flow of electrical currents through the smartphone screen. Touching the screen alters the flow, and the alteration triggers the touchscreen sensors to respond by performing various actions related to the touchpoints applied to the screen.

These current changes dictate the actions on the particular part of the screen at the moment, triggering whatever the requested command is to the device is based on what was touched.

Fingerprint Sensor

Our phones hold many of our most important details, so they are something we try to keep from getting lost from our possession. However, they are also small and therefore can slip from our possession easily or can be simply misplaced.

The concern is that anyone who finds the device will be able to get into it. But the security of smartphones has been enhanced by fingerprint access, meaning only the owner can get in.

Fingerprint sensors take an impression of the lines and ridges of your thumbprint, which is unique only to you. It then measures the distance between the ridges to verify that the user is in fact you. 


Working in tandem with the accelerometer, the pedometer is predominantly used by fitness apps to count steps. If you have a goal to take 15,000 steps per day, as long as your smartphone is on your person, the pedometer will sense your body movements and count your steps.

Modern pedometer sensors are smart enough to recognize when you are in motion and yet not actually walking.

If you jumped, rode a bike, sat in a moving vehicle, or even ran in place, the pedometer would recognize that you are not actually walking and would not count the steps.

While the accelerometer will also detect steps, the pedometer is a more refined sensor, as step counting is its primary task.

Barcode/QR Code Sensors

If you have been to a restaurant that is actively trying to be “green” you have probably been asked to scan a QR code with your phone to retrieve the establishment’s menu.

This is possible due to the barcode and QR code sensor that detects the light reflected by the scanned code, generating an analog signal that represents each bar in a barcode with a different voltage.

The combination of these signals is converted to a digital signal, which is then converted in the unique manifestation of that barcode’s information. Certain stores have customized apps to let you scan barcodes on products to price check them as well as to show detailed information, an important aspect in which this sensor is also a vital component.


Certain phones include a barometer, which is a sensor that detects air pressure. These are an important component of weather-related apps, as well as those that inform the user of their current altitude.

Besides atmospheric pressure, a barometer can detect distance from sea level and works with the GPS to figure out the air pressure in your current location.

Heart Rate Sensor

By using optical sensors and LED lighting, the heart rate sensor is able to detect the speed and pattern of your heart rate. Because there is a change in light intensity of the skin when a pulse pounds, the heart rate sensor is able to measure the heart rate by counting the frequency of those light changes.


The thermometer sensor exists in nearly every modern smartphone device. It serves two important and particular purposes.

The first is to monitor the temperature of the device itself. If the device gets overheated, the temperature sensor communicates to the phone that it needs to shut down in order to cool off to prevent frying the device.

Secondly, the temperature sensor reads the ambient temperature and can let you know the current temperature, rendering it in Fahrenheit or Celcius, depending on your preferred temperature measurement settings.

If you want to take your own temperature, you might need to download one of the best thermometer apps that we recommend. Please check it out.

Air Humidity Sensor

A less common sensor included in modern smartphones is the air humidity sensor which is able to measure the ambient air quality. When it calculates the humidity levels in the air, it relays the information to the user, letting them know of the current air quality.

Geiger Counter

The Geiger counter operates on a sensor that measures marine radiation levels. It has only been released in Japan, however, and as of today, exists built only into the Sharp Pantone 5 device. 

Soli Sensor

The Soli sensor is a tiny radar that was introduced by Google on the Pixel 4. Soli allowed you to track your movements on a microscopic scale at high speed and accuracy. Think about you interacting with your phone through hand gestures.


We hope you’ve learned about all the sensors embedded in your smartphone. Without those sensors, your phone wouldn’t be able to performs all these functions.

This list will keep growing as smartphones continue to get more advanced. For any questions or concerns, please use the comments section below.

Writer, Smart Home

For years technology has been a big part of Gardy's life. He's an Android guy with a secret love for Apple products. When not at work, you can usually catch him drawing with a pencil. He is a writer at Gotechtor covering streaming media, TVs, and everything smart-home related. 

Gardy Philogene

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