FRDM boards - DAP link

This is specifically regarding the FRDM-KL25Z board, but I assume it is similar for others.

Someone running one of my old creations had some issues, so lets try a new software version. That bricked everything. So I tried it on my side with two W10 laptops and an old KL25Z board: I got a 50/50 of succesful programming on one laptop, and via docking station of the other laptop. Direct connection to other laptop failed every single time.

I checked the website here: Nop, was running latest interface firmware. I remembered some old issues with W10 and USB disks, so I googled it, and via that I got in the end to: Which has way newer firmware available than what the mbed website claims is latest one! So a general request, maybe just put a link to that webpage for all the FRDM boards? Yes they are old, but they should work.

Next of course the question: Did this help? I put on the latest KL25Z firmware (0254), and behold, it now failed every single time…
Well, that was not what I was hoping for, maybe others have more luck, but I wonder what was changed exactly in 0254. Because since I now had to fix it anyway, I tried 0253, who knows? And on both my laptops, with and without docking station in between, it got a 100% functionality. Not a single time programming failed.

Anyway, I sent the person running my creation that 0253 firmware too, he used that, and also on his side everything ran flawless again.


  1. If you got issues with FRDM boards and programming, try other firmware from, and don’t only try the latest one if that doesn’t solve it.
  2. For Mbed staff, maybe just remove everything related to firmware versions from this website, and put instead links to

Hello Erik,

It’s good to see you back! How is Wim doing?
We miss your valuable support!



Wim must have been so long ago I don’t remember him anymore :grimacing:

And I did like looking into such stuff again (well more the code than the debugging why programming didn’t work). But I have little ideas on what to implement to really come back. Problem is you buy stuff these days which is cheaper / more effective than what you implement yourself.

I wasn’t a big fan of the larger push towards RTOS, but I do like how now there is the split option of going bare metal and RTOS. (Also happy I saw in time the old compiler would be shut down and I could copy my data).

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Hello Erik,
I learned also from your code when I started with Mbed, happy also to see your’e back.

The simple switch between baremetal and RTOS is really a great feature, although some controllers with enough resources for RTOS are pretty cheap. E.g. the RP2040 / Raspberry Pico.


Welcome back Erik, it is you!

This is the first time Erik has posted — let’s welcome them to our community!

This is on top of this thread, was your old username/account removed or why is this your first post?

I was not certain if we got second Erik or the old one is back to mbed. I reached out to you to the email I still have around, just before I was reading this thread.

If you got issues with the firmware, the best would be to create an issue in the Daplink Github repository. In this case, someone from NXP should review.

  1. For Mbed staff, maybe just remove everything related to firmware versions from this website, and put instead links to

I’ll ask Daplink codeowners if we shall do this. I would.

Because these forums didn’t exist yet when I left :wink: . We had different ones, and primarily the questions and answers section.