Step-by-step guide to printf on NRF51

RE: Step-by-step guide to printf on NRF51

Petter Myhre — Thu, 12 Nov 2015 09:15:34 GMT

Great that you got it working. Could you close the case or accept my answer by clicking the grey circle next to it?

RE: Step-by-step guide to printf on NRF51

RPDben — Wed, 11 Nov 2015 16:17:03 GMT

Turns out the last error was because I was mismatching the Baud rates. Thanks for helping me get something out, I will try and debug why it wasn't working initially.

RE: Step-by-step guide to printf on NRF51

RPDben — Wed, 11 Nov 2015 16:12:08 GMT

I tried re-setting up Termite and am now getting the output that is in the main question as a screenshot.

RE: Step-by-step guide to printf on NRF51

Petter Myhre — Wed, 11 Nov 2015 16:05:17 GMT

As I said in my answer Debug (printf) Viewer does not work on nRF51 because it doesn't have ITM. The tutorial I linked to explains how to set up Termite.

RE: Step-by-step guide to printf on NRF51

RPDben — Wed, 11 Nov 2015 15:59:05 GMT

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?

RE: Step-by-step guide to printf on NRF51

RPDben — Wed, 11 Nov 2015 15:35:57 GMT

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

RE: Step-by-step guide to printf on NRF51

Petter Myhre — Wed, 11 Nov 2015 15:33:42 GMT

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?

RE: Step-by-step guide to printf on NRF51

RPDben — Wed, 11 Nov 2015 15:11:41 GMT

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!).

RE: Step-by-step guide to printf on NRF51

Petter Myhre — Wed, 11 Nov 2015 15:04:06 GMT

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.