MCUXpresso SDKのトピックPRINTF (DbgConsole_Printf) doesn't work for negative float

PRINTF (DbgConsole_Printf) doesn't work for negative float

blmckinley — Thu, 29 Jan 2026 16:00:14 GMT

Using MCUXpresso
Product: MCUXpresso IDE
Version: MCUXpresso IDE v24.12 [Build 148] [2025-01-10]
Operating system: Windows 11
VM: OpenJDK 64-Bit Server VM (64 bit)

The PRINTF macro that resolves to DbgConsole_Printf is supposed to provide small, lightweight print to terminal features. But it does not print negative float values correctly. This is apparently a known issue but it took me 2 solid days of fooling around with my code trying to figure out why my values had the wrong sign.

The solution proposed in https://community.nxp.com/t5/MCUXpresso-SDK/Printing-negative-floats-with-DbgConsole-Printf-in-mcuxpresso/m-p/1795964#M4587
is not really adequate since stdio brings in all kinds of other libraries and expands the amount of flash memory required. That is the whole reason that the SDK even provides a lightweight print function.

So it is really NOT a good solution, and the issue should remain open. How is it that this bug still exists in the SDK after TWO entire years? This is a ridiculously straightforward problem to solve. Please fix the SDK and stop wasting your developers' valuable time.

Re: PRINTF (DbgConsole_Printf) doesn't work for negative float

mayliu1 — Mon, 16 Mar 2026 04:07:18 GMT

Hi @blmckinley ,

Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.

I suggest you can refer to this NXP community post:

Solved: Printing negative floats with DbgConsole_Printf in mcuxpresso SDK 2.15 - NXP Community

Please try it.

Best Regards

MayLiu

Re: PRINTF (DbgConsole_Printf) doesn't work for negative float

blmckinley — Tue, 17 Mar 2026 13:28:45 GMT

Thank you for the reply. As I mention in my post, although the printf() function does work for negative numbers, that is not a solution for a bug in the SDK function DbgConsole_Printf().

Your users deserve bug-free SDKs and I highly recommend you fix the bug as outlined.

Re: PRINTF (DbgConsole_Printf) doesn't work for negative float

mayliu1 — Mon, 30 Mar 2026 06:36:58 GMT

Hi @blmckinley ,

Thanks for your feedback, I have already created an internal ticket for your question.

Best Regards

May Liu