Confused with the pins assigned to NRF_LOG_INFO() and printf()

RE: Confused with the pins assigned to NRF_LOG_INFO() and printf()

beemavishnu — Mon, 01 Jul 2019 08:55:26 GMT

Now I got better clarity. Thank a lot for your inputs.

RE: Confused with the pins assigned to NRF_LOG_INFO() and printf()

Simonr — Mon, 01 Jul 2019 08:51:38 GMT

1. Please read more on RTT here, as it is a SEGGER proprietary technology. RTT uses the debug channel for communication, so it won't interfere with the UART peripheral.

2. Correct.

3. This is not a question. The link you provided explains how to configure the NRF_LOG modules.

Best regards,

Simon

RE: Confused with the pins assigned to NRF_LOG_INFO() and printf()

beemavishnu — Fri, 28 Jun 2019 13:57:53 GMT

Hello,

Now I am able to print using my custom board. I have further queries.

1) I got your point with respect to ‘ble_app_blinky’. Trying to understanding your statement “Applications using UART for serial communication can use the RTT (NRF_LOG_BACKEND_RTT_ENABLED) for debugging output” better. Assume in case ble_app_uart, serial communication uses UART and debug prints are configured to use over RTT.

a) If Serial communications uses UART then what peripheral is used to communicate to RTT.

b) Whether RTT uses UART or some other peripheral to communicate RTT viewer.

2) Whether “Debug Terminal” within Segger IDE is same as RTT viewer. For "Debug Terminal" I don't think UART is required.

3) I have gone through below link, but I could not find much details about “Log UART backend” and “Log RTT backend”.

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.3.0%2Fgroup__nrf__log.html&resultof=%22%4e%52%46%5f%4c%4f%47%5f%49%4e%46%4f%22%20

Please correct me if I am wrong in above understanding.

Thanks & Regards

Vishnu Beema

RE: Confused with the pins assigned to NRF_LOG_INFO() and printf()

Simonr — Thu, 27 Jun 2019 12:33:31 GMT

Hi Vishnu

2. Applications using UART for serial communication can use the RTT (NRF_LOG_BACKEND_RTT_ENABLED) for debugging output, but the blinky example uses BACKEND_UART as it doesn't use the UART for anything else.

3. You don't see the NRF_LOG_INFO outputs as they are configured to be output by the RTT.

Hope this helps to clarify things for you.

Best regards,

Simon

RE: Confused with the pins assigned to NRF_LOG_INFO() and printf()

beemavishnu — Thu, 27 Jun 2019 09:04:32 GMT

Hello Simon,

Thank you for your inputs.

Yes I am trying to implement on my custom board and as you mentioned I changed NRF_LOG_BACKEND_UART_TX_PIN to my required pin and worked fine.

But to get better clarity, please let me know your inputs. Below queries are on Development kit.

2) If there is only one UART, then how to print debug prints and at the same time use UART to communicate with other device (Serial communications).

3) If I load ‘ble_app_uart’ example as is into Development kit I am seeing only debug prints in printf() but not in NRF_LOG_INFO(). If both use same UART why debug prints in NRF_LOG_INFO() are not printing.

Thanks & Regards

Vishnu Beema

RE: Confused with the pins assigned to NRF_LOG_INFO() and printf()

Simonr — Thu, 27 Jun 2019 08:38:26 GMT

Hi Vishnu

My bad. Seems like I misunderstood a few things in your inquiry. What you want, is to debug your custom board, am I right? I assumed you were struggling to print the ble_app_uart data from the pins on your external chip.

The NRF_LOG_INFO prints from ble_app_blinky are printed by NRF_LOG_BACKEND_UART, so you change the pin by setting NRF_LOG_BACKEND_UART_TX_PIN to what the output pin from your external board.

You could also take a look at the nRF52DK user guide to see how to debug an external board using your DK.

Best regards,

Simon

RE: Confused with the pins assigned to NRF_LOG_INFO() and printf()

beemavishnu — Wed, 26 Jun 2019 13:20:15 GMT

Hi Simo,

Sorry, still I am confused.

1) In ble_app_blinky how to change UART pins without changing pca10040.h file. In this example there is no ‘comm_params’ as in ‘uart’ example.

2) If there is only one UART, then how to print debug prints and at the same time use UART to communicate with other device (Serial communications).

Thanks & Regards

Vishnu Beema

RE: Confused with the pins assigned to NRF_LOG_INFO() and printf()

Simonr — Wed, 26 Jun 2019 12:57:25 GMT

Hi Vishnu

1. This is correct!

2. You should not make any changes in pca10040.h. Please leave all the pca100xx.h files the way they were when you downloaded the SDK. If you want to change the pins for UART, please configure this in the uart_init function by replacing the RX, TX, RTS, and CTS_PIN_NUMBERs with the values you want.

Yes, NRF_LOG_INFO uses UART to communicate with the terminal. The rest of your questions should be solved by configuring the UART pins correctly.

Best regards,

Simon