KY-025 Magnetic Reed Switch Sensor Module with LM393 for Arduino
KY-025 Magnetic Reed Switch Sensor Module with LM393 for Arduino
KY-025 Magnetic Reed Switch Sensor Module with LM393 for Arduino
Buy the KY-025 Magnetic Reed Switch Sensor Module with LM393 online in Pakistan from Robostan.pk. This compact magnetic detection module is designed for Arduino, ESP32, Raspberry Pi, robotics, smart home automation, security alarm systems, and DIY electronics projects.
The KY-025 Reed Switch Module uses a normally open magnetic reed switch that responds to a nearby magnet. When a suitable magnetic field is present, the switch contacts close, changing the electrical signal available to the connected microcontroller.
The module includes an LM393 voltage comparator, adjustable potentiometer, analog-labeled output (AO), digital output (DO), and onboard indicator LEDs, providing convenient connections for electronic switching and magnetic detection applications.
Key Features
- KY-025 magnetic reed switch sensor module
- Normally open (NO) magnetic reed switch
- Integrated LM393 voltage comparator
- Operating voltage typically 3.3V to 5V DC
- Four-pin connection interface
- Analog-labeled output (AO)
- Digital comparator output (DO)
- Adjustable comparator reference using onboard potentiometer
- Power and detection indicator LEDs
- Sealed glass reed switch sensor
- Contactless magnetic activation
- Compatible with Arduino digital inputs
- Suitable for ESP32 and Raspberry Pi with appropriate interfacing
- Compact PCB with mounting hole on common versions
- Ideal for magnetic alarms and position detection
Technical Specifications
- Product Name: KY-025 Magnetic Reed Switch Sensor Module
- Model Number: KY-025
- Sensor Type: Magnetic Reed Switch
- Switch Configuration: Normally Open (NO)
- Comparator IC: LM393
- Operating Voltage: Typically 3.3V to 5V DC
- Output Interfaces: AO and DO
- Digital Output: HIGH / LOW Comparator Signal
- AO Output: Reed Switch Signal
- Reference Adjustment: Onboard Trimmer Potentiometer
- Common Potentiometer: 3296W-104
- Common Reed Switch Size: Approximately 2 x 14mm
- Indicator LEDs: Power and Detection
- Connection Pins: AO, GND, VCC, DO
- Typical PCB Dimensions: Approximately 36 x 15mm
- Detection Method: Magnetic Contact Switching
- Compatible Platforms: Arduino, ESP32, Raspberry Pi and Other Suitable Microcontrollers
Applications
- Arduino magnetic detection projects
- Door and window security alarms
- Smart home automation
- Magnetic proximity sensing
- Cabinet and drawer position detection
- Robotics position monitoring
- Magnetic limit-switch projects
- DIY security monitoring circuits
- ESP32 IoT alarm systems
- Raspberry Pi GPIO projects
- Electronic switching experiments
- Educational sensor projects
- Equipment position monitoring
How Does the KY-025 Magnetic Sensor Work?
The KY-025 Magnetic Reed Sensor contains two flexible metal contacts enclosed in a sealed glass capsule.
In the absence of a suitable magnetic field, the contacts remain open. When a magnet approaches, the magnetic force causes the contacts to close, completing an electrical connection.
This switching action changes the sensor circuit signal. The onboard LM393 comparator processes the signal and generates a digital output that can be monitored by a microcontroller.
The KY-025 is suitable for detecting the presence or absence of a magnet rather than measuring precise magnetic field strength.
KY-025 Analog and Digital Outputs
The module commonly provides two output terminals:
- AO (Analog-Labeled Output): Provides the electrical signal associated with the reed switch circuit.
- DO (Digital Output): Provides a comparator-controlled HIGH or LOW signal.
Important: Although one terminal is labeled AO, the KY-025 uses a mechanical reed switch. This output should not be advertised as an accurate continuous measurement of magnetic field strength.
The onboard potentiometer adjusts the comparator reference level, not the inherent magnetic sensitivity of the reed switch itself.
KY-025 Module Pinout
- AO: Reed switch signal output
- GND: Ground connection
- VCC: Positive power supply
- DO: Digital comparator output
Always follow the actual PCB pin labels, as connector arrangements can vary between manufacturers.
Arduino Compatibility
The KY-025 is compatible with Arduino UNO, Arduino Nano, Arduino Mega, and other controllers with suitable digital input pins.
A typical Arduino UNO wiring arrangement is:
- KY-025 VCC: Arduino 5V
- KY-025 GND: Arduino GND
- KY-025 DO: Arduino digital pin D3
- KY-025 AO: Arduino A0, if the second output is required
The Arduino can monitor the digital output using the digitalRead() function and respond when the magnetic switch changes state.
Applications include controlling a buzzer, turning on an LED, recording magnetic switching events, or activating a suitable alarm circuit.
ESP32 and Raspberry Pi Compatibility
The KY-025 can also be used in compatible ESP32 and Raspberry Pi projects.
When working with 3.3V-only GPIO systems, select a suitable module supply and ensure that all output signal levels remain within the controller's permitted voltage range.
A Raspberry Pi can monitor the digital output through a GPIO input. If analog sampling is required, an external analog-to-digital converter may be used.
Door and Window Magnetic Alarm Projects
The KY-025 Reed Switch Module is useful for creating simple magnetic door and window monitoring systems.
Place the sensor near a compatible magnet mounted on a moving door, window, or cabinet.
As the magnet moves toward or away from the sensor, the reed switch changes state. A connected controller can use this information to operate an audible alarm, indicator light, or wireless notification system.
Detection distance depends on magnet strength, orientation, mounting position, and the switch characteristics.
KY-025 vs KY-021 Magnetic Reed Switch
- KY-025: A magnetic reed switch breakout commonly equipped with an LM393 comparator, potentiometer, indicator LEDs, and separate output terminals.
- KY-021: A smaller and simpler magnetic reed switch breakout intended for basic digital magnetic detection.
Choose the KY-025 when the larger comparator-equipped module is required. For straightforward digital reed contact detection, the KY-021 may be sufficient.
KY-025 vs KY-024 Hall Effect Sensor
- KY-025: Uses a mechanical reed switch that opens and closes in a magnetic field.
- KY-024: Uses a solid-state linear Hall Effect sensor for magnetic field sensing.
Unlike the KY-024, the KY-025 does not provide calibrated analog magnetic field measurements.
Why Choose the KY-025?
Simple Magnetic Detection: Detects suitable magnets without physical contact between the magnet and module.
Built-In Comparator: Provides a convenient digital output for microcontroller applications.
Adjustable Reference: Onboard potentiometer allows adjustment of the digital comparator setting.
Compact Construction: Suitable for small electronic projects and monitoring systems.
Educational Value: Useful for learning magnetic switching, digital inputs, comparators, and sensor circuits.
Important Usage Notes
- The KY-025 uses a mechanical reed switch, not a Hall Effect IC.
- Magnetic detection depends on magnet strength and orientation.
- The AO output does not provide calibrated magnetic field strength.
- The potentiometer does not change the magnetic switching characteristics of the reed capsule.
- Mechanical switch contact bouncing may occur.
- Software debouncing may be needed for stable detection.
- Handle the sealed glass reed switch carefully.
- Verify the actual PCB pinout before applying power.
- Use a regulated supply within the specified voltage range.
- Keep output voltages compatible with the connected microcontroller.
- Do not connect high-current loads directly to the sensor outputs.
- Use a suitable relay or driver circuit for external loads.
- Do not use this module as the sole safety device in critical installations.
Package Contents
- 1 x KY-025 Magnetic Reed Switch Sensor Module with LM393
External magnet, Arduino board, and connecting wires are not included unless specified separately.
Buy KY-025 Magnetic Reed Sensor in Pakistan
Looking for a KY-025 Magnetic Reed Switch Module with LM393 in Pakistan? Shop online at Robostan.pk for magnetic sensors, reed switch modules, Arduino electronics, ESP32 boards, Raspberry Pi accessories, robotics components, and DIY electronic project supplies.
The KY-025 is suitable for students, engineers, technicians, hobbyists, and electronics developers working on magnetic detection and automation projects.
Order your KY-025 Reed Switch Sensor Module from Robostan.pk with nationwide delivery across Pakistan, including Lahore, Karachi, Islamabad, Rawalpindi, Faisalabad, Multan, Peshawar, and other cities.
Robostan.pk – Build. Innovate. Create.
Pickup available at Robostan
Usually ready in 24 hours
KY-025 Magnetic Reed Switch Sensor Module with LM393 for Arduino
Buy the KY-025 Magnetic Reed Switch Sensor Module with LM393 online in Pakistan from Robostan.pk. This compact magnetic detection module is designed for Arduino, ESP32, Raspberry Pi, robotics, smart home automation, security alarm systems, and DIY electronics projects.
The KY-025 Reed Switch Module uses a normally open magnetic reed switch that responds to a nearby magnet. When a suitable magnetic field is present, the switch contacts close, changing the electrical signal available to the connected microcontroller.
The module includes an LM393 voltage comparator, adjustable potentiometer, analog-labeled output (AO), digital output (DO), and onboard indicator LEDs, providing convenient connections for electronic switching and magnetic detection applications.
Key Features
- KY-025 magnetic reed switch sensor module
- Normally open (NO) magnetic reed switch
- Integrated LM393 voltage comparator
- Operating voltage typically 3.3V to 5V DC
- Four-pin connection interface
- Analog-labeled output (AO)
- Digital comparator output (DO)
- Adjustable comparator reference using onboard potentiometer
- Power and detection indicator LEDs
- Sealed glass reed switch sensor
- Contactless magnetic activation
- Compatible with Arduino digital inputs
- Suitable for ESP32 and Raspberry Pi with appropriate interfacing
- Compact PCB with mounting hole on common versions
- Ideal for magnetic alarms and position detection
Technical Specifications
- Product Name: KY-025 Magnetic Reed Switch Sensor Module
- Model Number: KY-025
- Sensor Type: Magnetic Reed Switch
- Switch Configuration: Normally Open (NO)
- Comparator IC: LM393
- Operating Voltage: Typically 3.3V to 5V DC
- Output Interfaces: AO and DO
- Digital Output: HIGH / LOW Comparator Signal
- AO Output: Reed Switch Signal
- Reference Adjustment: Onboard Trimmer Potentiometer
- Common Potentiometer: 3296W-104
- Common Reed Switch Size: Approximately 2 x 14mm
- Indicator LEDs: Power and Detection
- Connection Pins: AO, GND, VCC, DO
- Typical PCB Dimensions: Approximately 36 x 15mm
- Detection Method: Magnetic Contact Switching
- Compatible Platforms: Arduino, ESP32, Raspberry Pi and Other Suitable Microcontrollers
Applications
- Arduino magnetic detection projects
- Door and window security alarms
- Smart home automation
- Magnetic proximity sensing
- Cabinet and drawer position detection
- Robotics position monitoring
- Magnetic limit-switch projects
- DIY security monitoring circuits
- ESP32 IoT alarm systems
- Raspberry Pi GPIO projects
- Electronic switching experiments
- Educational sensor projects
- Equipment position monitoring
How Does the KY-025 Magnetic Sensor Work?
The KY-025 Magnetic Reed Sensor contains two flexible metal contacts enclosed in a sealed glass capsule.
In the absence of a suitable magnetic field, the contacts remain open. When a magnet approaches, the magnetic force causes the contacts to close, completing an electrical connection.
This switching action changes the sensor circuit signal. The onboard LM393 comparator processes the signal and generates a digital output that can be monitored by a microcontroller.
The KY-025 is suitable for detecting the presence or absence of a magnet rather than measuring precise magnetic field strength.
KY-025 Analog and Digital Outputs
The module commonly provides two output terminals:
- AO (Analog-Labeled Output): Provides the electrical signal associated with the reed switch circuit.
- DO (Digital Output): Provides a comparator-controlled HIGH or LOW signal.
Important: Although one terminal is labeled AO, the KY-025 uses a mechanical reed switch. This output should not be advertised as an accurate continuous measurement of magnetic field strength.
The onboard potentiometer adjusts the comparator reference level, not the inherent magnetic sensitivity of the reed switch itself.
KY-025 Module Pinout
- AO: Reed switch signal output
- GND: Ground connection
- VCC: Positive power supply
- DO: Digital comparator output
Always follow the actual PCB pin labels, as connector arrangements can vary between manufacturers.
Arduino Compatibility
The KY-025 is compatible with Arduino UNO, Arduino Nano, Arduino Mega, and other controllers with suitable digital input pins.
A typical Arduino UNO wiring arrangement is:
- KY-025 VCC: Arduino 5V
- KY-025 GND: Arduino GND
- KY-025 DO: Arduino digital pin D3
- KY-025 AO: Arduino A0, if the second output is required
The Arduino can monitor the digital output using the digitalRead() function and respond when the magnetic switch changes state.
Applications include controlling a buzzer, turning on an LED, recording magnetic switching events, or activating a suitable alarm circuit.
ESP32 and Raspberry Pi Compatibility
The KY-025 can also be used in compatible ESP32 and Raspberry Pi projects.
When working with 3.3V-only GPIO systems, select a suitable module supply and ensure that all output signal levels remain within the controller's permitted voltage range.
A Raspberry Pi can monitor the digital output through a GPIO input. If analog sampling is required, an external analog-to-digital converter may be used.
Door and Window Magnetic Alarm Projects
The KY-025 Reed Switch Module is useful for creating simple magnetic door and window monitoring systems.
Place the sensor near a compatible magnet mounted on a moving door, window, or cabinet.
As the magnet moves toward or away from the sensor, the reed switch changes state. A connected controller can use this information to operate an audible alarm, indicator light, or wireless notification system.
Detection distance depends on magnet strength, orientation, mounting position, and the switch characteristics.
KY-025 vs KY-021 Magnetic Reed Switch
- KY-025: A magnetic reed switch breakout commonly equipped with an LM393 comparator, potentiometer, indicator LEDs, and separate output terminals.
- KY-021: A smaller and simpler magnetic reed switch breakout intended for basic digital magnetic detection.
Choose the KY-025 when the larger comparator-equipped module is required. For straightforward digital reed contact detection, the KY-021 may be sufficient.
KY-025 vs KY-024 Hall Effect Sensor
- KY-025: Uses a mechanical reed switch that opens and closes in a magnetic field.
- KY-024: Uses a solid-state linear Hall Effect sensor for magnetic field sensing.
Unlike the KY-024, the KY-025 does not provide calibrated analog magnetic field measurements.
Why Choose the KY-025?
Simple Magnetic Detection: Detects suitable magnets without physical contact between the magnet and module.
Built-In Comparator: Provides a convenient digital output for microcontroller applications.
Adjustable Reference: Onboard potentiometer allows adjustment of the digital comparator setting.
Compact Construction: Suitable for small electronic projects and monitoring systems.
Educational Value: Useful for learning magnetic switching, digital inputs, comparators, and sensor circuits.
Important Usage Notes
- The KY-025 uses a mechanical reed switch, not a Hall Effect IC.
- Magnetic detection depends on magnet strength and orientation.
- The AO output does not provide calibrated magnetic field strength.
- The potentiometer does not change the magnetic switching characteristics of the reed capsule.
- Mechanical switch contact bouncing may occur.
- Software debouncing may be needed for stable detection.
- Handle the sealed glass reed switch carefully.
- Verify the actual PCB pinout before applying power.
- Use a regulated supply within the specified voltage range.
- Keep output voltages compatible with the connected microcontroller.
- Do not connect high-current loads directly to the sensor outputs.
- Use a suitable relay or driver circuit for external loads.
- Do not use this module as the sole safety device in critical installations.
Package Contents
- 1 x KY-025 Magnetic Reed Switch Sensor Module with LM393
External magnet, Arduino board, and connecting wires are not included unless specified separately.
Buy KY-025 Magnetic Reed Sensor in Pakistan
Looking for a KY-025 Magnetic Reed Switch Module with LM393 in Pakistan? Shop online at Robostan.pk for magnetic sensors, reed switch modules, Arduino electronics, ESP32 boards, Raspberry Pi accessories, robotics components, and DIY electronic project supplies.
The KY-025 is suitable for students, engineers, technicians, hobbyists, and electronics developers working on magnetic detection and automation projects.
Order your KY-025 Reed Switch Sensor Module from Robostan.pk with nationwide delivery across Pakistan, including Lahore, Karachi, Islamabad, Rawalpindi, Faisalabad, Multan, Peshawar, and other cities.
Robostan.pk – Build. Innovate. Create.
