How to printing double type variable at SEGGER_RTT_printf?

[Gon]

Hi, all.

I'm using "SEGGER_RTT_printf" for debugging. Because have no uart port on my development board. I want print double type variable like below.

---

double pi = 3.141592;

SEGGER_RTT_printf(0, "print double type : %lf\n", pi);

---

But print result is nothing. What can i do for using it?

Please kindly guide.

[Vidar Berg]

Hi,

SEGGER_RTT_printf doesn't support the double format, but you can use sprintf or similar to generate a string beforehand that you can pass to this function.

[Anders Strand]

If precision is not important , doing (%d, (int) value) will work.

[Gon]

Hi, Vidar Berg.

Firstly, thanks to your kindly comment. I think the use of "sprintf" is a good idea.

But i just want a way to add "double type print" in "SEGGER_RTT_printf()". I guess to difficult add that way. But If it makes the function, i think it will be convenient at debugging.

[Vidar Berg]

Happy to help. The RTT related code is provided by Segger, but assume the reason for not having float conversion is to reduce memory footprint.

[Gon]

Hi, Vidar Berg.

I understood. I'll take using "sprintf" for optimization source. Thank you!