printf() make something wrong

[zhengrui]

Hi ,I'm working on nrf_MESH v2.20 and nrf_SDK v15.0 and SESV3.40.

In the project of light_switch->proxy_client ,I use printf() to print something and it can work well and everything is OK.But after I pull out USB (for debugging ) the board can not work anymore.I have test it and I know that printf() in main(void) and in other functions ,for example, prov_provisionee_cb_link_established(prov_bearer_t * p_bearer) can cause different resoult.

It still work when I print something in main() after I pull out USB,but it doesn't work in other functions.And there is no information if I don't add printf() but it show the error when I use printf().

Also I remember I ever changed the codes about put_char() in SDKv15.0 because it isn't compatible with SES but  I don't think it is important for this trouble because I don't use uart.

So anyone have the same question and I need your help .

Thanks in advance.

[Håkon Alseth]

Hi,

 

In the project of light_switch->proxy_client ,I use printf() to print something and it can work well and everything is OK.But after I pull out USB (for debugging ) the board can not work anymore.

If I understand correctly, your firmware does not run when not in debug mode.

Could this be the issue? https://devzone.nordicsemi.com/f/nordic-q-a/34784/conflicting-types-for-_putchar/133776#133776

 

Kind regards,

Håkon

[zhengrui]

Thanks ,it works now though it still has an error report just as the picture above.

I can find the _putchar() is defined in retarget.c but I don't use it or .h file.Is there some connection?

And I have tried this file in ble_uart example,I find that if I define RETARGET_ENABLE as true and remove retarget.c it still works in debug mode but never run when not in debug mode (if RETARGET_ENABLE as failure my firmware will always run).

I don't know why the program acts this way.

[Håkon Alseth]

zhengrui said:

Thanks ,it works now though it still has an error report just as the picture above.

Could you explain in step-by-step what you are doing and what error message is shown?

From your current sequence, it seems like you are removing power from the debugger while the debug session is on-going, which will terminate the session. 

[zhengrui]

In the ble_uart example we can know it use retarget.c file and the code-changed function _putchar() is defined in it.Also RETARGET_ENABLE is true in sdk_config.h.

Now I remove retarget.c in ble_uart project and it can work in debug mode but the firmware does not run when not in debug mode (RETARGET_ENABLE is true).

If I define RETARGET_ENABLE as 0, the firmware can run anytime.

[Håkon Alseth]

zhengrui said:

If I define RETARGET_ENABLE as 0, the firmware can run anytime.

 That is good, meaning that SES then disables the inbuilt __putchar() used for the debugging terminal.

 Keep this to 0 if you are not debugging.

 

Kind regards,

Håkon