Understanding IoT Sensors: A Comprehensive Guide

This tutorial section focuses on IoT (Internet of Things) and covers these sub-topics:

• Main tutorial IoT section
• IoT article
• Cellular IoT
• Components
• Sensors
• INDIAN companies
• Antenna Types
• Wireless technologies
• IoT transceiver SoC

As we know, the IoT market is booming, and sensors are a major component with huge market potential.

There are two main divisions in an IoT network: the digital back end and the front end, which mainly consists of IoT sensors.

A major benefit of this booming market is that semiconductor companies will capture a significant portion of it.

We’ll explore IoT sensors used for optical, ambient light, temperature, pressure, inertia, humidity, proximity, gesture, touch, and fingerprint sensing applications. These sensors are based on MEMS (Micro Electro-Mechanical Systems) technology.

If the sensors are digital, it’s straightforward to interface with a microcontroller using SPI. If the sensors are analog, an Analog-to-Digital converter is needed (as mentioned later from Analog Devices). Alternatively, a Sigma Delta modulator can be used to convert analog data to SPI output. It’s easy to interface SPI signals with any microcontroller device.

Pressure Sensor

This type of sensor detects pressure around the Earth, which is very useful for developing altimeters and barometers.

The LPS25H pressure sensor from ST-Microelectronics is one such IoT sensing device, often used for GPS-based navigation.

Accelerometer and Gyroscope

An accelerometer is used to detect vibration, tilt, and linear acceleration.

It is used for implementation of pedometers, leveling, vibration alerts, anti-theft systems, and more.

A gyroscope is used to measure angular velocity. Gyroscopes are mainly used in 3D mice, games, and athlete training.

InvenSense Inc. has developed the ICM-20628, which is a low-power 6-axis combined accelerometer and gyroscope solution.

Temperature Sensor

It’s used to control the performance of an IoT device at varied temperatures.

One example of a temperature sensor is the ADT7320.

It is a digital temperature sensor with a range from -40°C to +150°C.

It is interfaced directly with a microcontroller in an IoT device.

Humidity Sensor

Similar to a temperature sensor, it’s also used to control the performance of the device.

The HTU21D from Measurement Specialties is a digital humidity sensor.

The NPA-700 series of humidity sensors from GE Sensing provides digital output data using the industry-standard I2C protocol. The Si70xx series from Silicon Laboratories Inc. is also used as humidity and temperature sensors.

Proximity Sensor

Silicon Labs’ optical sensor family enables sensing UV Index, ambient light, long-range proximity, heart rate/pulse oximetry, and motion with 2D or 3D gestures.

Model series Si114x, Si1132, Si1120, and Si1102 are sensors from Silicon Labs used as infrared proximity sensors.

Touch Sensor

Silicon Labs has 8-bit and 32-bit Microcontrollers that are used as capacitive touch sense applications, such as sliders, wheels, touch buttons, liquid level sensing, and capacitive proximity sensing.

Analog to Digital Converter

The AD7176-2 from Analog Devices is used as an analog-to-digital converter.

It works on very low bandwidth input signals originating from sensors.

It has a faster settling time. It is very accurate and has a high-resolution sigma-delta ADC.