I decided to create an article regarding this type of potentiometer: multi-turn rectangular potentiometer, which is similar to what is shown below:
As you can see in the image above, you see number 3, 2, and 1. The lead below 1 is for VCC (+5V), lead below 2 is for Signal (usually an analog pin in the Arduino board), and the lead below 3 is for GND. The red jumper wire is connected to the lead below 1. The blue jumper wire is connected to lead below 2, and the green jumper wire is connected to lead below 3. Please refer to the image below.
Now, we need to connected these jumper wires to the following:
Red – VCC on the board (power rail, can be connected to Atmega328 pin 22)
Blue – Analog pin 0 (A0 or Atmega328 pin 23)
Green – GND on the board (power rail, can be connected to Atmega328 pin 20)
Image below shows the connection from the potentiometer to the DIY Arduino board:
The alternative way of connecting VCC and GND is through the Atmega328P-PU microcontroller pins as shown below. This is tantamount to getting power from the chip itself, and not from the power source before reaching the microcontroller (as above).
Once all these are already connected accordingly, then we can upload a sketch to the board, using the following codes.
Open the Serial Monitor from the Arduino IDE, and try to rotate the small golden knob at the top. Values should change as you rotate the knob.
I hope this article helped you one way or the other, as tutorial on how this kind of potentiometer is rarely seen in the Internet.
I hope to hear some comments as well. Thanks!