Chapter 1: Introduction to Sensors and Modules
Movement Sensor
Radio-Frequency Identification (RFID)
Magnetic Field Sensor
Touch Sensor
Tracking Sensor
Flame Sensor
Heartbeat Sensor
Led Modules
Joystick Modules
Sound Modules
Relay Modules
What Are Sensors and Modules?
Sensors: Devices that detect and measure physical properties such as temperature, humidity, distance, light, gas concentration, etc., and convert them into signals that can be read by a microcontroller.
Modules: Pre-assembled units that provide specific functionality, such as relays for switching high-power devices, motor drivers, communication interfaces, etc.
Importance in Embedded Systems
Data Collection: Sensors collect essential data from the environment.
Actuation: Modules control various devices based on sensor inputs and logic.
Automation: Enable the creation of smart, automated systems.
General Applications
Home Automation: Automated control of lights, appliances, and security systems.
Environmental Monitoring: Monitoring of weather conditions, air quality, and soil moisture.
Robotics: Sensors and modules for navigation, obstacle detection, and interaction.
Healthcare Devices: Monitoring vital signs such as heart rate, temperature, and blood oxygen levels.
Industrial Automation: Automation of manufacturing processes, monitoring equipment, and ensuring safety.
Agriculture: Monitoring soil conditions, controlling irrigation systems, and ensuring optimal growth conditions for crops
Chapter 2: Types of Sensors
Different Types of Sensors
Sensors can be categorized into two main types:
Direct Sensors: These sensors can convert a non-electrical stimulus directly into an electrical signal without any intermediate stages. Example: a thermocouple, which converts temperature to voltage.
Indirect Sensors: These sensors require multiple conversion steps to transform the measured signal into an electrical signal. Example: a fiber-optic displacement sensor, which converts light to current, then to photons, and back to current.
All sensors generally fall into one of these two categories. However, there are other ways to classify them:
Active and Passive Sensors
Active Sensors: Require an external power source to operate and are also known as parametric sensors, meaning their output is a function of the parameter being measured.
Passive Sensors: Generate their own electrical signal without needing an external power source, also known as self-generating sensors.
Contact and Non-contact Sensors
Contact Sensors: Require physical contact with the stimulus to operate.
Non-contact Sensors: Do not require physical contact with the stimulus to function.
Absolute and Relative Sensors
Absolute Sensors: Measure stimuli on an absolute scale, providing a direct measurement.
Relative Sensors: Measure stimuli relative to a fixed or variable reference.
List of Sensors
Here is a comprehensive list of the most commonly used sensors:
Infrared Sensor (IR Sensor)
An IR sensor is an electronic device that measures and detects infrared radiation in its surrounding environment. Essentially, it is a light-emitting diode that can detect changes in color, heat, and IR radiation. Read more about the IR sensor here.
Temperature Sensor
Temperature sensors measure the amount of heat energy or coldness generated by an object or system, allowing us to detect any physical change in temperature. These sensors produce either an analog or digital output. More details on temperature sensors can be found here.
Proximity Sensor
A proximity sensor detects the presence of nearby objects without any physical contact. It often emits an electromagnetic field or a beam of electromagnetic radiation (like infrared) and looks for changes in the field or return signal. Different targets require different proximity sensors.
Ultrasonic Sensor
An ultrasonic sensor measures the distance of a target object by emitting ultrasonic sound waves and converting the reflected sound into an electrical signal.
Accelerometers
Accelerometers measure proper acceleration, which is the rate of change of velocity of a body in its own instantaneous rest frame. This differs from coordinate acceleration, which is acceleration in a fixed coordinate system.
Gyroscope Sensor
A gyroscope sensor measures and maintains the orientation and angular velocity of an object. More advanced than accelerometers, gyroscopes can measure the tilt and lateral orientation of the object.
Pressure Sensor
A pressure sensor measures the pressure of gases or liquids. Pressure is the force required to stop a fluid from expanding, expressed as force per unit area. These sensors usually act as transducers, generating a signal as a function of the pressure imposed.
Hall Effect Sensor
A Hall effect sensor measures the magnitude of a magnetic field, with output voltage proportional to the magnetic field strength. These sensors are used for proximity sensing, positioning, speed detection, and current sensing applications.
Load Cell
A load cell is a force transducer that converts forces like tension, compression, pressure, or torque into an electrical signal. As the applied force increases, the electrical signal changes proportionally.
Light Sensor
A light sensor is a passive device that converts light energy, whether visible or in the infrared spectrum, into an electrical signal. Often known as photoelectric devices or photo sensors, they convert light energy (photons) into electricity (electrons).
Color Sensor
A color sensor detects the color of a material, usually on the RGB scale, categorizing the color as red, blue, or green. These sensors often include filters to reject unwanted IR and UV light.
Touch Sensor
Touch sensors detect touch and operate as switches when touched. They are used in lamps, touch screens of mobile devices, and other applications requiring an intuitive user interface.
Tilt Sensor
A tilt sensor measures the change in tilt and monitors inclination and vertical rotation in structures. It produces an electrical signal proportional to the degree of tilt in multiple axes (uniaxial and biaxial).
Vibration Sensor
Also known as a piezoelectric sensor, a vibration sensor is a flexible device used to measure various processes involving vibrations.
Water Flow Sensor
A water flow sensor measures the flow rate of water and calculates the amount of water flowing through a pipe, typically measured in liters per hour or cubic meters.
Heartbeat Sensor
A heartbeat sensor measures the heart rate, or the speed of the heartbeat.
Level Sensor
Level sensors detect the level of liquids, fluids, and fluidized solids, including slurries, granular materials, and powders with an upper free surface.
Gas Sensor
Gas sensors, also known as gas detectors, detect and identify different types of gases. They are commonly used to detect toxic or explosive gases and to measure gas concentration.
Soil Moisture Sensor
A soil moisture sensor measures the volumetric content of water within the soil.
Rotary Encoder
A rotary encoder, or shaft encoder, is an electro-mechanical device that converts the angular position or motion of a shaft or axle into analog or digital output signals.
Tachometer
A tachometer, or revolution counter, measures the rotation speed of a shaft or disk in a motor or machine, usually displaying the revolutions per minute (RPM) on a calibrated analog dial or digital display.
Chapter 3: Types of Modules
List of Modules
Relay Module
A relay module is an electrically operated switch used to control high-power devices. It allows a low-power microcontroller to switch high-power circuits safely.
Motor Driver Module
Motor driver modules, such as the L298N or DRV8825, are used to control the speed and direction of motors. These modules can drive various types of motors, including DC and stepper motors.
Bluetooth Module
Bluetooth modules, such as the HC-05 and HC-06, enable wireless communication between devices. They are commonly used for remote control and data transfer applications.
Wi-Fi Module
Wi-Fi modules like the ESP8266 and ESP32 provide wireless connectivity to the internet. They are used in IoT projects to connect devices to the network.
GSM Module
GSM modules, such as the SIM900 and SIM800, allow microcontrollers to communicate over cellular networks for sending SMS, making calls, and accessing the internet.
GPS Module
GPS modules, such as the Neo-6M, provide location data by receiving signals from GPS satellites. They are used in navigation and tracking applications.
OLED Display Module
OLED display modules are used to display information with high contrast and low power consumption. They come in various sizes and resolutions.
LCD Display Module
LCD display modules, like the 16x2 and 20x4 character displays, are used to show alphanumeric data. They are widely used in projects requiring user interface displays.
Touchscreen Module
Touchscreen modules combine a display with touch input capability, allowing for intuitive user interfaces. Common types include resistive and capacitive touchscreens.
Camera Module
Camera modules, such as the Raspberry Pi Camera Module, capture still images and video. They are used in surveillance, photography, and computer vision projects.
SD Card Module
SD card modules enable microcontrollers to read from and write to SD cards, providing expandable storage for data logging and file storage applications.
RFID Module
RFID modules, like the MFRC522, are used for reading and writing data to RFID tags. They are commonly used in access control and inventory management systems.
NFC Module
NFC (Near Field Communication) modules, such as the PN532, allow for short-range wireless communication between devices. They are used in contactless payment systems and data transfer.
Buzzer Module
Buzzer modules produce sound and are used for alarms, notifications, and user feedback in various projects.
IR Transmitter and Receiver Module
IR transmitter and receiver modules enable remote control communication using infrared light. They are commonly used in TV remotes and other consumer electronics.
Sound Sensor Module
Sound sensor modules detect sound levels and convert them into electrical signals. They are used in sound-activated projects and noise monitoring.
PIR Motion Sensor Module
PIR (Passive Infrared) motion sensor modules detect human movement by sensing infrared radiation changes. They are used in security and automation applications.
Gas Sensor Module
Gas sensor modules detect various gases, such as methane, carbon monoxide, and smoke. They are used in safety and environmental monitoring.
Light Sensor Module
Light sensor modules measure light intensity and convert it into an electrical signal. They are used in automatic lighting and environmental monitoring.
Soil Moisture Sensor Module
Soil moisture sensor modules measure the moisture content in soil. They are used in agriculture and gardening to monitor and control irrigation systems.
Water Flow Sensor Module
Water flow sensor modules measure the flow rate of water through a pipe. They are used in water management and conservation projects.
pH Sensor Module
pH sensor modules measure the acidity or alkalinity of a solution. They are used in environmental monitoring, aquariums, and agriculture.
Current Sensor Module
Current sensor modules, such as the ACS712, measure the current flowing through a circuit. They are used in power monitoring and energy management applications.
Voltage Sensor Module
Voltage sensor modules measure the voltage level in a circuit. They are used to monitor battery levels and power supplies.