Complete Sensor Guide

You must have noticed token display boards at many places like food stores, hospitals, banks, various takeaways, etc. Token display systems are used to display token numbers. As these display boards show numeric information, these are easily designed using 7-segment LEDs. The commercial models use large 7-segment LEDs to display token numbers. It is even…

Proximity sensors are used to detect something approaching near. These sensors are useful in many applications like collision avoidance, obstacle detection, path following, touchless sensing, motion detection, and object detection. There are different types of proximity sensors like optical, ultrasonic, capacitive, inductive, and magnetic. The capacitive, inductive, and magnetic proximity sensors are used in specific…

Optical fingerprint scanners are prominent security devices nowadays. These scanners are low-cost and easy to use with any embedded hardware platform. The scanners have built-in memory and a controller to store and compare fingerprints. Usually, optical fingerprint scanners have a USB and/or UART port to communicate with external controllers or computers. The scanner handles enrollment…

A majority of middle-aged people suffer from health issues like asthma and breathing problems, particularly in cities. Air pollution is the major cause of it. In this project, we have designed a portable device that detects different air pollution metrics and displays them on a small OLED screen. People with respiratory issues can use the…

A very common feature in Android and iOS fitness apps is calculating the number of steps the user walks and the distance he covers. These apps calculate the number of steps walked by the user either using GPS location and manipulating the geospatial data or by monitoring the acceleration vector of the device using an…

Metal detectors offer several useful applications. A few examples include: Security checks Positioning detection for production equipment Elevator floor control Mineral prospecting Unearthing relics and artifacts Collecting traffic statistics  Metallic waste detection  Game entertainment Each detection circuit employs different electronic components and designs. A simple metal detector can be constructed using an RLC circuit. In…

BMP180 is a digital pressure sensor designed for low-power, low-voltage operation in mobile phones, navigation devices, and personal digital assistants. The sensor has an I2C interface to communicate sensor data. It can operate on 2.5~3.6V and consumes only 12 uA even in the ultra-high-resolution mode. The sensor can be used for several applications, including measuring…

Environment sensors are of great importance in embedded applications. Many temperature sensors measure the ambient temperature or temperature of a surface. For measuring water temperature and other fluids, waterproof temperature sensors are required. One of such temperature sensors is DS18B20. This sensor can measure the temperature of the air, liquids like water, and ground. The…

A security alarm detects unauthorized entry into a home or building. In the past, these security devices simply triggered a loud siren when an intrusion was detected. As technology advanced, the systems were equipped with GSM modems to send an SMS alert to the home or building owner whenever an intrusion was detected.  One drawback…

Small organic light-emitting diode (OLED) displays are commonly used in embedded devices. This is because OLEDs generally cost the same as character LCDs but feature a better user interface (UI) and user experience (UX).  Typically, embedded OLED screens are used to display textual messages, but what about videos? For example, is it possible to playback…

Several consumer devices now involve temperature monitoring. For example, most of the air conditioners on the market feature climate control, where the AC continuously monitors the ambient temperature of a room and accordingly regulates the air conditioning. Even some digital clocks now have temperature monitors embedded in them. Many other consumer appliances also offer temperature…

Raspberry Pi is the most popular single-board computer. As an embedded microcomputer, data acquisition is almost essential in Raspberry Pi. Though Pi has several GPIO (General Purpose Input/Output) pins, it does not have any built-in or onboard analog-to-digital converter. Therefore, Pi on its own cannot sample data from analog sensors. In embedded applications, analog sensors…

RFID is a popular tagging and identification technology. Radio frequency identification involves one RFID tag and the second RFID reader. RFID tags and labels are low-cost and easily available. Compared to barcode tracking systems, RFID solutions have several advantages. One of the apparent advantages of RFID over barcodes is that it does not require a…

Motion tracking sensors are used in applications like robotics, gesture recognition, vehicle stabilization, position control in drones/quadcopters, pointing devices, game controllers, and fitness tracking devices. One of the popular motion tracking sensors is MPU6050. It is a six-axis MEMS motion tracking sensor that includes a MEMS accelerometer and a MEMS gyroscope. The sensor also has…

A peephole, spyhole, or peekhole is a small opening through the door that allows viewing from inside to outside. Such door holes allow seeing outside the door without opening it. Usually, these door holes have a fisheye lens to have a wider look of the outside. In this project, we have developed a digital version…

Have you ever struggled to fix nails on a wall perfectly parallel to the floor or ceiling? In this project, we have modeled an electronic-level device useful in placing anything perfectly parallel. This device is prototyped on the popular microcontroller board – the Arduino. It uses very few components to build, only an accelerometer sensor…

Electromyography (EMG) is a medical procedure that evaluates the health conditions of muscles and nerve cells. These cells transmit electrical signals that cause muscles to contract or relax. EMG is used to read these signals and plot them as numbers or graphs. Typically, EMG is performed by doctors as one part of a diagnostic tool…

Detecting the physical conditions of a robot is always useful in robotic applications. Particularly if the robot is a rover and is designed to explore different terrains. In such applications, there are instances when the state of the robot has to be detected. It may involve detection of collision or fall, change in orientation of…

Container shipping is a common transport medium. In fact, 80 percent of international trade in goods is carried by sea. Containers are large and reliable, offering a standard size that makes them portable between ships, trains, and trucks.  However, the loss of items transported via containers is not an uncommon problem in the shipping industry.…

Cardiac disease is a concern as people age. In fact, heart problems are fairly common in men over the age of 50 but are increasingly affecting younger adults, regardless of gender. This is attributed, at least partially, to more sedentary and stressful lifestyles and unhealthy habits. But genetics may also play a role. Electrocardiogram (ECG)…