How to implement soft uart in Pca10028?

RE: How to implement soft uart in Pca10028?

bjorn-spockeli — Mon, 17 Jul 2017 13:22:16 GMT

See the comment section of the answer below for more context regarding this solution.

RE: How to implement soft uart in Pca10028?

bjorn-spockeli — Tue, 11 Jul 2017 09:16:19 GMT

Happy to help!

RE: How to implement soft uart in Pca10028?

Newbie — Tue, 11 Jul 2017 09:08:23 GMT

Hi, Its working now. I used NRF_LOG_DEFERRED to 0 and now I can see the output in RTT viewer. Thanks, Shailav

RE: How to implement soft uart in Pca10028?

bjorn-spockeli — Tue, 11 Jul 2017 09:02:41 GMT

Try setting NRF_LOG_DEFERRED to 0 and then comment out NRF_LOG_PROCESS() in main.

RE: How to implement soft uart in Pca10028?

Newbie — Tue, 11 Jul 2017 09:00:19 GMT

None of the above call NRF_LOG_INFO works in BLE_GAP_EVT_ADV_REPORT. I am using NRF_LOG_PROCESS() in the main . Though when I am printing // Start scanning for peripherals and initiate connection // with devices that advertise NUS UUID. NRF_LOG_INFO("Uart_c Scan started\r\n");

scan_start();

The above code works but when I am calling NRF_LOG_INFO in BLE_GAP_ADV_REPORT it doesn't works. Thanks

RE: How to implement soft uart in Pca10028?

bjorn-spockeli — Tue, 11 Jul 2017 08:52:33 GMT

So none of the NRF_LOG_INFO calls under the BLE_GAP_EVT_ADV_REPORT case in on_ble_evt() shows up in RTT viewer? Did you set NRF_LOG_DEFERRED to 0 or did you call NRF_LOG_PROCESS() in the main while loop?

RE: How to implement soft uart in Pca10028?

Newbie — Tue, 11 Jul 2017 08:35:40 GMT

Hi, I am able to print something on RTT_viewer by implementing your suggestions but I also want to print the mac address, Rssi and adv data of nearby ble devices as I am using ble_app_uart_c(central) code. I am not able to see above data in rtt_viewer. My code snippet is as follows

const ble_gap_evt_adv_report_t * p_adv_report = &p_gap_evt->params.adv_report;
{
         // scan is automatically stopped by the connect
         err_code = bsp_indication_set(BSP_INDICATE_IDLE);
            APP_ERROR_CHECK(err_code);
             NRF_LOG_INFO("Mac address %02x%02x%02x%02x%02x%02x\r\n",
               p_adv_report->peer_addr.addr[5],
               p_adv_report->peer_addr.addr[4],
               p_adv_report->peer_addr.addr[3],
               p_adv_report->peer_addr.addr[2],
               p_adv_report->peer_addr.addr[1],
               p_adv_report->peer_addr.addr[0]
            );

		NRF_LOG_INFO("Data: ");

	        for(i=0;i<17;i++)
		{
		     NRF_LOG_INFO("%02x", p_adv->data[i]);
		}
									
		NRF_LOG_INFO(" \r\nRSSI: %d\n", p_adv->rssi);							
}

RE: How to implement soft uart in Pca10028?

bjorn-spockeli — Tue, 11 Jul 2017 07:37:57 GMT

You also need to either set NRF_LOG_DEFERRED to 0 in sdk_config.c or call NRF_LOG_PROCESS() in the main while loop.

RE: How to implement soft uart in Pca10028?

Newbie — Tue, 11 Jul 2017 07:01:27 GMT

Hi, I am unable to see any output using NRF_LOG_INFO. I am attaching my sdk_config.h file and main.c file above. Thanks

RE: How to implement soft uart in Pca10028?

bjorn-spockeli — Tue, 11 Jul 2017 06:53:13 GMT

You should use the NRF_LOG_INFO macro instead of SEGGER_RTT_printf() , e.g.

NRF_LOG_INFO("Heart Rate Sensor Start!\r\n");

RE: How to implement soft uart in Pca10028?

Newbie — Tue, 11 Jul 2017 05:49:37 GMT

Hi Bjørn, I was able to set up RTT viewer. When I am writing this SEGGER_RTT_WriteString(0, "Hello World!\n"); I am able to see output in RTT viewer but when I am using the printf function for example SEGGER_RTT_printf(0, "variable value: %d\n", err_code); I am getting error as ._build\nrf51422_xxac.axf: Error: L6218E: Undefined symbol SEGGER_RTT_printf (referred from main.o). What can be the problem? Thanks, Shailav

RE: How to implement soft uart in Pca10028?

bjorn-spockeli — Mon, 10 Jul 2017 13:01:24 GMT

Yes, you can use Segger's RTT instead of the UART by setting NRF_LOG_BACKEND_SERIAL_USES_RTT to 1 and NRF_LOG_BACKEND_SERIAL_USES_UART to 0 in skd_config.h. See this Infocenter page for more information on the logger module.

RE: How to implement soft uart in Pca10028?

Newbie — Mon, 10 Jul 2017 12:49:44 GMT

Hi Bjørn, As of now I am not using nrf52840. I have nrf51 and nrf52832(pca10040). My application is as follows: I am scanning the nearby ble devices using code ble_app_uart_c(central role). Now uart pins 11 and 9 are used for tx and rx so that I can see the output on my terminal. Can I see the output in terminal without wasting this pins? I want to send some at commands to esp8266 using pins 11 and 9 but as these pins are already in use I am not able to do this. Any suggestions? Thanks

RE: How to implement soft uart in Pca10028?

Mahesh Venkitachalam — Mon, 10 Jul 2017 09:54:32 GMT

A bit banged UART is not that hard to implement, especially for low baud rates - for a simple example see:

electronut.in/.../

RE: How to implement soft uart in Pca10028?

bjorn-spockeli — Mon, 10 Jul 2017 09:05:34 GMT

Hi Shailav,

I am afraid that we do not have any examples showing how create a software-based("bit-banged") UART for the nRF51 Series. Have you considered using the nRF52840 that has two UARTs?

Best regards

Bjørn