NanoBoy reference board 

The MK20DX256 based
NanoBoy reference board
with SWD debugger interface





  • Open source, license free.
  • No warranty, either express or implied, is given for the PCB.  Agree our terms before buying the PCB. No alteration on silkscreens. We shall not be liable for any claims, expenses, damages, and loss of profits, opportunities or information arising from the use of this PCB.



1) Many through hole parts, easier to assemble for DIY users

2) SWD interface ready for programming and debugging

3) SWD clock activity LED indicator to monitor SWD operation.

4) Low cost SWD programmer/debugger made by EVBplus, selling at $22 (USBDM-SWD)

5) Debugging using the free Freescale's KDS without memory size limit or the free Keil IDE with memory size limit
usbdm.sourceforge.net/USBDM_V4.12/html/index.html.   It uses a FRDM board as a SWD debugger.
If the above link does not work, you can cut and paste it to the URL address bar.

Keil IDE tutorial

6) It's open source, license free. 

The Gerber files are available at Oshpark



Our journey to make a Teensy 3.2 with a debugger:


Added a SWD header on
the Teensy 3.1


Tested it with our SWD debugger and it worked OK


Made the rev. A,
and it worked OK


Made the rev. B,
and it worked OK



The top view
after it's snapped and
broken into 2 pieces.


The bottom view
after it's snapped and
broken into 2 pieces.


The right section can be  connected to a debugger.




Many engineers, EE students and universities use commercial IDE, such as KDS and Keil IDE.  We will make a Teensy3 compatible board with a debugger for professional and educational markets. 


Arduino UNO is a registered trademark of Arduino LLC.

Teensy is a trademark of PJRC.com LLC

NanoBoy is a trademark of EVBplus LLC