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

Relays and Drivers



A driver circuit and single 5V relay that can control greater voltages/currents. Can make a direct connection to the microprocessor as this board has a relay driver circuit to drive the relay coil. Contacts typically rated for 10 amps.

Also called: relay, one channel relay, KY019.

Found in kits: 20 sensors, 37 sensors, 45 sensors.


(Typical relay module)
• Voltage: 3.3V to 5.0V
• LED: Power
• Size: 20mm X 60mm
• Relay ratings are shown on the relay. Often 30VDC or 120VAC at greater the 5A.
• Typically SPST, NC/C/NO.

Some boards have a 1N4007 flyback diode for the relay’s coil.

May have activation LED. Transistor-driven with pulldown.

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.

Module Pin-out:

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

Alternate Modules:

There are relay modules that are alternates to the one included in the 37 sensor kits. Some are mechanical relays, some are solid-state relays.
Image: Single 5V relay module. LED indicates operation. Relay operated from Vcc with the jumper in place, or from pin marked JD_VCC if the jumper is removed. Relay activated by grounding the signal input.

Image: Single 5V relay module. Red LED indicates power. Green LED indicates operation. Input at 5V operates the relay.

Image: Eight 5V relay module. Eight individual LEDs indicates operation. Relay operated from Vcc with the jumper in place, or from pin marked RVCC if the jumper is removed. Relay activated by grounding the signal input.

Image: Dual MOSFET PWM control module 400W 5V-36V. LED indicates operation.


Image: IRF520-based solid-state relay. 3.3V-5V operation. LED indicates activation. Can drive 0-24V at 1 amp without a heat sink. Could drive up to 5 amps with a heat sink. Signal input at Vcc operates the relay.

For the IRF520 module, the pin connections are the logic-side (microcontroller) connections. Ground and VCC are the control circuit ground and +5V respectively. SIG is the activation line. Active is a high level (5V) and inactive is 0V.

(SIG can be driven at up to 10V to fully turn on the IRF520. Driving SIG at 5V actually only partially turns on the IRF520, and as a result it dissipates more heat.)

VIN and GND on the screw terminal is for the connection to the power supply (0-24V) on the driven side of the module. The V+ and V- connections on the other screw terminal are for the load. To drive a 12V incandescent lamp, for example, V+ and V- connect to the lamp. VIN would be 12V.

V+ and VIN are connected on the board.

IRF520 datasheet:
Linked file: irf520ns.pdf

Image: Single 5V solid-state relay module. LED indicates operation. Input at 5V operates the relay. Can drive 240VAC at 2 amps.

Image: Solid-state relay. 3-32VDC activation. LED indicates activation. Can control 24-380VAC at 40 amps.

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