Skip to content

Archive

Sensors

7 articles
Tech 19 Sep 2026 6 min read

Infrared Sensors Measure Different Physical Effects

An infrared sensor is not a single measurement technology. “IR sensor” can describe a reflective proximity detector, a PIR motion detector, a non-contact temperature sensor, an optical encoder, or an infrared receiver. They all operate with radiation outside the visible spectrum, but the quantity being measured is different. That distinction determines what the sensor can detect, how far it can work, and which environmental conditions can produce false or weak readings.

Tech 19 Sep 2026 7 min read

GPS Distance and IMU Balance on ESP32 Measure Different Things

A GPS module and an IMU can both feed an ESP32 with numbers that describe motion, but they observe different physical quantities. Treating them as interchangeable sensors creates bad measurements quickly. A GPS receiver estimates geographic position from satellite signals. Two position fixes can be converted into an approximate distance across Earth’s surface. An IMU such as the MPU-6050 measures acceleration and angular rate along its axes. Those measurements can be used to estimate tilt, rotation, and short-term motion.

Tech 11 Sep 2026 8 min read

How Pocket Detection Prevents Accidental Phone Touches

A phone in a pocket can experience many of the same things as a phone in your hand: movement, pressure against the screen, and occasional taps from fabric or other objects. Yet many phones can reduce accidental screen input while they are covered or tucked away. This behavior is often called pocket detection, pocket mode, or a similar name. It is not one universal feature with one fixed design. Phone makers can combine sensor readings, touchscreen data, device state, and software rules in different ways.

Tech 09 Sep 2026 8 min read

Why Your Phone Compass Can Point the Wrong Way

A maps app can know where you are yet show your direction incorrectly. The location marker may be on the right street while its direction indicator points sideways, rotates while you stand still, or seems to face the wrong way. That is possible because location and direction are different measurements. A phone can estimate its position from satellite navigation, Wi-Fi, mobile networks, and other information, while its compass heading depends heavily on sensing the magnetic field around the device.

Tech 06 Sep 2026 8 min read

How Your Phone Compass Knows Which Way You Are Facing

A map can show your position correctly while the direction arrow points the wrong way. You turn the phone, but the arrow hesitates, swings around, or seems several degrees off. Then a compass app asks you to move the device through the air to improve its accuracy. These behaviours make more sense once you separate two questions: Where is the phone? and Which way is it facing? Location systems can help answer the first question, but a phone usually needs additional sensors to estimate the second when it is standing still.

Tech 04 Sep 2026 8 min read

Why Your Phone’s Compass Can Point the Wrong Way

A map app can know your location correctly while the direction arrow points sideways. A compass app can also appear accurate in one place and drift badly in another. These problems make more sense once you separate two questions that phones answer in different ways: Where am I? and Which way am I facing? Satellite navigation can help answer the first question. To estimate the second while you are standing still, a phone commonly relies on magnetic and motion sensors. Those sensors are useful, but the magnetic one can be disturbed by ordinary objects around you.

Tech 04 Sep 2026 9 min read

Why Your Phone Screen Turns Off During Calls

Put a phone to your ear during a call and its screen will usually go dark. Move the phone away and the display normally wakes again. This small behavior prevents your cheek or ear from pressing on-screen controls while you are talking. The feature depends on proximity sensing: the phone tries to determine whether something is very close to the front of the device. The basic idea is simple, but the exact sensor hardware and software behavior vary between phone models.