Where does printf print to?

[Protoneer]

I have a PCA10001 setup and I am using SDK v9. I have opened the UART example in CrossStudio.

It compiles/builds and I am debugging with breakpoints.

My question is where does printf 's get displayed? I am not seeing it on the UART but I know UART is working because the app_uart_put is echoing my input text.

I am however not seeing the printf's...

[Einar Thorsrud]

I have no experience with CrossStudio, but it seems you have to customize __putchar(), which is used by printf().

[Protoneer]

I see. Lets take CrossStudio out of the picture. If I use GCC and make files, where will the SDK example output it then?

[Einar Thorsrud]

You have to retarget printf() by using a custom _write() (If you were using Keil you would have to use a custom fputc() instead). This is implemented in the SDK, but you have to including components/libraries/uart/retarget.c in your Makefile. There are more details in this thread.