Library for PMT9123 for Nordic nRF51


This section highlights the setup and operating guide to integrating PMT9213 with the ST Nucelo L476 Development Board.



  • 1. PC or Notebook with Windows Operating System
  • 2. ST Nucelo L476 Development Board
  • 3. PMK9123IP-TVIT Aduino Enabled Board
  • 4. USB Cable (one end with Mini-B)


Please connect the board as show below.


Supplying Power

Connect the one end of the USB to the PC USB and the other to the Nucleo USB Mini-B as shown in the figure below.


I am assuming that you already know and are able to download the code at this point. For ST Nucleo Dev Board, no RESET is needed after the code is downloaded. You should observe that the RED LED will change color to GREEN after the code is downloaded successfully, as illustrated below.


Functional Test

To quickly make sure that the PMK9123 is functional with the ST Nucleo Dev Board, you can turn on the knob to see if the LED on the left, changes intensity.

  • Clockwise: LED D1 should get brighter
  • Counter Clockwise: LED D1 should get dimmer


If the intensity changes, that means you are good to go.

Tera Term

For those who seek to quantify the movement of the wheel (or how much it has moved), you can use another method to see the relative movement of the wheel and how it translates to numbers. Here are a few more steps to get there:

1. Open up Tera Term. If you do not have Tera Term, you can download here.

2. Once you have your Tera Term open, go to File > New Connection or use the Hot Key "Alt + N".

3. Select "Serial".

4. On the Port selection, click on the drop down menu and select the port that describes "STMicroelectronics STLink Virtual Com Port".


5. Click on "OK"

6. You should then see a tera term window with blinking cursor. Now you can rotate the wheel in either clockwise or counter clockwise direction.

  • Clockwise direction yields increasing number.
  • Counter clockwise yields decreasing number.

Have fun with this and let us know if you have any further questions!

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