Completing the FRDM-KL25Z Board

I had pre-ordered some FRDM-KL25Z boards, and they came with the extra headers in plastic bags (see this post):

Pre-ordered Freedom board with headers

Pre-ordered Freedom board with headers

I have received as well a batch of the production boards, and for these I need to order the missing parts. So for everyone else, here are the Farnell part numbers:

Here is a table of all the parts which are on the pre-production ‘white’ board, but not populated on the ‘black’ production board, with reference to the board schematics:

Schematics Farnell Part# # Description Comment
J10 1668351 1 SAMTEC – SSW-106-01-G-D ‘Arduino’ header 2×6, 2.54 mm
J1, J9 1668364 2 SAMTEC – SSW-108-02-G-D ‘Arduino’ header 2×8, 2.54 mm
J2 1668373 1 SAMTEC – SSW-110-01-G-D ‘Arduino’ header 2×10, 2.54 mm
J3, J4, J11 1704910 3 MOLEX – 22-28-4022 – BOARD-BOARD CONNECTOR HEADER, 2WAY, 1ROW Jumper header, 2.54 mm
J6, J8 1667728 2 SAMTEC – FTS-105-01-L-D Debug Connector 2×5 1.27 mm, (FYI, mating cable is 1667659)
U5 2136670 1 ATMEL – AT45DB161E-SHD-B – DATAFLASH, 16MBIT, SPI, 8WSOIC Serial flash (connected to OpenSDA K20, *not* to the KL25Z!)
BT1 908654 1 KEYSTONE – 3003 – BATTERYHOLDER 20mm Battery holder for CR2032 battery
(BT1) 1823479 1 CR 2032 Coin Li Battery,  3V CR2032 battery

I assume that things like the jumper headers are readily available, and are only required if I cut the trace between the jumpers on the board.

Alternative parts from for the SWD/JTAG parts:

  • JTAG/SWD cable: 855-M50-9110542
  • JTAG/SWD connector: 855-M50-3600542
  • JTAG/SWD plug: 855-M50-3300542

One or two debug connectors are only needed if I want to bypass OpenSDA, or to recover a CPU directly with a P&E Universal Multilink.

The Serial Flash chip is only connected to the K20 OpenSDA device, and currently not used.

❗ Note: On some(!!!!) of the black production boards, R25 (near the 8 MHz crystal) is not populated, while it is on the white boards. Having the 1 MOhm resistor requires the PEE (USB) clock to run in ‘high gain’ main, while without R25 it has to run in ‘low power’ mode. See Tutorial: USB CDC with the KL25Z Freedom Board.

Happy upgrading 🙂


22 thoughts on “Completing the FRDM-KL25Z Board

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  9. Hi Erich,
    I have bought all the parts you suggest and “completed” my KL25Z (and also KL05Z and K20D50M using similar parts) but I’m facing a puzzle.

    I added the battery holder as suggested, but when I place a battery in the socket the board does not start up. I programmed a simple “blink” program to the board using USB, and checked that as soon as I plug in the USB power it starts blinking. However, it does not blink (in fact none of the LEDs light up) with a CR2032 in the battery holder.

    I have scoured the Freescale documentation, but all I can find is vague words about how it can work with USB power, direct DC input, or battery. So far I have found nothing which tells me *how* to get it working from a battery. I guess there must be something I am missing.

    Have you ever powered any of these boards from the CR2032? Can you gove any hints on how to do it?

    Many thanks,


    • Hi Frank,
      I have not powered it with a coin battery (yet). I saw that with the RevE boards ( they have changed the circuit around the battery, maybe because of the issue you are seeing? Looking at the RevD schematics I see the diode D1, and I know this diode has caused problems for me ( Can you measure the voltage after that didode? Maybe the voltage drop is too high for the current you have, so shortcutting/removing that diode will help?


  10. Hi Erich,
    I got a FRDM Kl25Z board and i started learning about it. As soon as we connect the board to the computer using opensda, we will get a drive with name FRDM-KL25Z showing 127 MB free of 127 MB. what is this 127 MB actually means because we have only 128 Kb of flash and 16 Kb of RAM.


    • No, these numbers are only virtual, and not real. There are no files stored on the board that way, it is only used to fake a memory stick so you can copy the files to it to program the KL25Z.


      • Thank you very much for your response..
        Do we have a process to create a file in that FRDM-KL25Z drive to store data in to that file directly. if we can do so then is that same as writing data in to flash..?.


        • Yes, there are several options for that. The OpenSDA MSD bootloader writes to the flash of the KL25Z. But you can implement as well a MSD bootloader or other USB class on the KL25Z to implement whatever you want/need.


  11. Hi Erich,
    Can i implement this by using any components in code warrior…?
    Is this similar to your “USB MSD Host for the Freedom Board” in any form. Can i use FAT_filemanager component to create file to store data in flash..?
    please excuse me if my questioning in not in proper way or order..

    Thanks in advance


  12. Pingback: Using the Freescale Freedom (FRDM-KL43Z) to Debug other Boards | MCU on Eclipse

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