SONGLE Single Relay Module for Arduino

  • Type: SPDT (Singe Pole Double Throw)
  • Coil Voltage: 5VDC
  • Contact Rating: 10A 250VAC/10A 125VAC/10A 30VDC


Click to access SRD(T73).pdf

3 Pin design requires 5V supply, Ground and a signal pulled to HIGH for switching. A clue to whether this type of relay is working or not is that the switch is audible.




These pins function as follows:

SO: The module’s serial output.   Your Arduino will read this output.

CS:  Chip Select.   Setting low, selects the Module and tells it to supply an output that is synchronize with a clock

SCK : The Serial Clock… an input from your Arduino.

VCC: 5V supply

GND:  Ground.

– (or Minus):   The K thermocouple minus input.

+ ( or Plus):  The K Thermocouple plus input.

IMPORTANT NOTE– Most K thermocouples come with a red lead and a yellow lead.  The red lead is normally your negative connection and the yellow lead is your positive.  That is industry standard.

That said, some of the suppliers for the module are different, and will provide you a thermocouple with red indicating positive.

The way to know is if you increase the temperature at the thermocouple tip, and the indication goes lower. (Henry’s bench, 2017)


Artwork: The basic idea of a thermocouple: two dissimilar metals (gray curves) are joined together at their two ends. If one end of the thermocouple is placed on something hot (the hot junction) and the other end on something cold (the cold junction), a voltage (potential difference) develops. You can measure it by placing a voltmeter (V) across the two junctions. (Explainstuff, 2018)

DS18B20 One Wire Thermometer


Click to access DS18B20.pdf


Explainstuff, 2018. Thermocuples. [online] Available at: <; [Accessed 12 April 2018].
Henry’s Bench, 2017. MAX6675 Temp module arduino manual and tutorial. [online] Available at: <> [Accessed 12 April 2018].



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