37 Sensors Overview

Sensor.Engine MICRO

  1. Sensor.Engine MICRO Features
  2. Pinout and Pin use
  3. BASIC Overview
  4. SEM Library functions

37+ Sensors

  1. Analog Hall-effect
  2. Analog Joystick
  3. Analog Temperature
  4. Ball Switch
  5. Bi-color LED
  6. Button
  7. Character LCD
  8. Flame
  9. Hall-effect Switch
  10. HMI Display
  11. Humidity and Temperature
  12. IR Receiver
  13. IR Transmitter
  14. Keypad
  15. LASER
  16. Light Cup
  17. Liquid
  18. Mercury Switch
  19. Microphone
  20. Multicolor Flashing LED
  21. Obstacle Avoidance
  22. Photo Interruptor
  23. Photoresistor
  24. Piezo Driver or Annunciator
  25. Pulse
  26. Reed Switch
  27. Relays and Drivers
  28. RGB LED
  29. Rotary Encoder
  30. Servo
  31. Shock and Impulse
  32. Speaker
  33. Temperature 18B20
  34. Temperature Threshold
  35. Touch Sensor
  36. Tracking
  37. Ultrasonic Distance

USBmicro U4xx

  1. U401
  2. U421
  3. U451



  1. Controlling MedeaWiz Sprite

Reed Switch



A switch that closes in the presence of a magnetic field. Module outputs the analog sensor signal, as well as (for some modules) a digital signal that is switched high when the sensor level crosses a preset threshold. The threshold is set via the potentiometer.

Also called: magnetic spring switch, mini reed switch, KY025.

Found in kits: 20 sensors, 37 sensors, 45 sensors (larger board).

Found in kits: 37 sensors, 45 sensors (smaller board).


• Voltage: 3.3V to 5.0V
• LED: Power
• Size: 20mm X 60mm

The mini reed switch module includes a 10k ohm resistor for pull-up or pull-down, depending on wiring. Normally open, closed in presence of magnetic field.

There are a number of different sources for these modules. Not every module that looks similar to the ones here behaves exactly the same. Check the specific module that you have for differences in function, voltage levels, pinout, and inactive/active states. Some modules have been found to have incorrectly labeled pins and even poorly soldered components.

Image: Reed switch schematic. Reed switch represented by button.

Module Pin-out:

Image: Typical/common pinout. Always check the pinout for the module that you have.

Image: Typical/common pinout. Always check the pinout for the module that you have.

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