Step-by-step guide to printf on NRF51

[RPDben]

Hi,

I can't seem to get printf working on the ble_app_cts_c example. I can't seem to find a definitive step-by-step guide as to how to get this working. Any help would be much appreciated.

Some more info:

I am using the main.c and retarget.c from Martin's post here: devzone.nordicsemi.com/.../

I then Build and Load it onto the nRF51 dk. I then click Debug -> Start Debugging. Then I open the Debug (printf) Viewer and run the program.

Nothing appears in the box. I am using Kiel v5.16.

Thanks,

EDIT:

Termite is communicating but receiving these values

[Petter Myhre]

It seems the Debug Viewer uses ITM:

The Debug (printf) Viewer is a special serial window that can exchange data with the microcontoller. For Cortex-M microcontrollers, the window displays printf-data received from the Instrumentation Trace Macrocell (ITM). With some special target code (see CMSIS) data can be sent to a Cortex-M microcontroller.

The CPU in nRF51 doesn't include an ITM, the CPU in nRF52 has it, but I haven't tested this functionality myself.

You can send your printf-data through the virual com port provided by the Segger chip, and see it in a terminal on your computer.

This tutorial should be helpful to you.

[RPDben]

I have this working already, I specifically wanted to get printf working. Is it not possible to use printf with the nrf51? The reason for this is I want to use the example as-is, without having to change every single printf function (there are a lot!).

[Petter Myhre]

I just tested the ble_app_cts_c example from SDK 10.0.0. The printf works out of the box, CTS Start! appears in the terminal. Maybe you can explain a bit more about what you are doing? What version of the SDK are you using?

[RPDben]

Which terminal are you talking about? The Kiel built-in one that I mentioned?

I am using SDK 9.0.0 with softdevice 8.0.0

[RPDben]

I have just downloaded and tried with SDK 10.0.0 and still nothing comes up in Debug (printf) viewer I assume for the same reason as before. Nothing also comes up if I try Termite. What terminal are you using to view this?