How to print UART message in "ble_app_uart" project in SDK15.2

RE: How to print UART message in "ble_app_uart" project in SDK15.2

Vidar Berg — Fri, 22 Mar 2019 09:46:07 GMT

Hi Chianglin,

There's only one UART instance on the 52832. The Jlink chip acts as a UART<->USB bridge when you use P.0.06 and P.0.08

RE: How to print UART message in "ble_app_uart" project in SDK15.2

chianglin — Fri, 22 Mar 2019 09:32:38 GMT

Hi Vidar,,

As well know, EVM have a "JLINK CDC UART".

I use EVM to test "ble_app_uart" project and I execute following setting:

    app_uart_comm_params_t const comm_params =
    {
        .rx_pin_no    = RX_PIN_NUMBER,
        .tx_pin_no    = TX_PIN_NUMBER\,
        .rts_pin_no   = RTS_PIN_NUMBER,
        .cts_pin_no   = CTS_PIN_NUMBER,
        .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
        .use_parity   = false,
#if defined (UART_PRESENT)
        .baud_rate    = NRF_UART_BAUDRATE_115200
#else
        .baud_rate    = NRF_UARTE_BAUDRATE_115200
#endif
    };

When I use "printf" function to out a debug message via UART interface, both "CDC UART" and "UART which use P0.06 for TXD and P0.08 for RXD" will get the same debug message.

Can I print different debug message to these two UART port?

For example, print "ABC" to CDC UART, and print "123" to the other UART port.

Thank you,

Chianglin

RE: How to print UART message in "ble_app_uart" project in SDK15.2

Vidar Berg — Wed, 20 Mar 2019 12:04:24 GMT

Hi,

Glad to hear that it works now, thanks for the update.

Best regards,

Vidar

RE: How to print UART message in "ble_app_uart" project in SDK15.2

chianglin — Wed, 20 Mar 2019 11:38:49 GMT

Hi Vidar,

It's work now. It should have something wrong in my previous process step.

Thank you for your serious support.

Best Regards,

Chianglin

RE: How to print UART message in "ble_app_uart" project in SDK15.2

chianglin — Wed, 20 Mar 2019 11:26:49 GMT

Hi Vidar,

I think P0.18 and P0.19 don't have problem to define as UART, because this 2 pins can work correct when I use "peripheral\uart" project.

The "nRF UART APP" can not find the BLE device which describe In my previous mail. May be the device had been crash, so BLE can not work.

The only change between “BLE can work or not" is "I modify the tx_pin_no and rx_pin_no in structure "comm_params".

Would you please tell me why my device is crash after I do these change?

Thank you,

Chianglin

RE: How to print UART message in "ble_app_uart" project in SDK15.2

Vidar Berg — Wed, 20 Mar 2019 11:10:10 GMT

[quote userid="34970" url="~/f/nordic-q-a/44952/how-to-print-uart-message-in-ble_app_uart-project-in-sdk15-2/177288"]Can I modify TXD to P0.18 and RXD to P0.19 for UART output?[/quote]

It shouldn't be a problem, but make sure that the RXD pin isn't left floating as that may cause framing errors, etc due to noise.

RE: How to print UART message in "ble_app_uart" project in SDK15.2

chianglin — Wed, 20 Mar 2019 10:39:25 GMT

Hi Vidar,

Can I modify TXD to P0.18 and RXD to P0.19 for UART output?

Can I modify following code to do this purpose?

static void uart_init(void)
{
    uint32_t                     err_code;
    app_uart_comm_params_t const comm_params =
    {
        .rx_pin_no    = 19	/*RX_PIN_NUMBER*/,
        .tx_pin_no    = 18	/*TX_PIN_NUMBER*/,
        .rts_pin_no   = RTS_PIN_NUMBER,
        .cts_pin_no   = CTS_PIN_NUMBER,
        .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
        .use_parity   = false,
#if defined (UART_PRESENT)
        .baud_rate    = NRF_UART_BAUDRATE_115200
#else
        .baud_rate    = NRF_UARTE_BAUDRATE_115200
#endif
    };

    APP_UART_FIFO_INIT(&comm_params,
                       UART_RX_BUF_SIZE,
                       UART_TX_BUF_SIZE,
                       uart_event_handle,
                       APP_IRQ_PRIORITY_LOWEST,
                       err_code);
    APP_ERROR_CHECK(err_code);
}

In original source code, the TXD, RXD is define at P0.06, P0.08. The UART can print message and I can find BLE device on "RF UART APP".

But when I modify to P0.18 and P0.19, the "nRF UART APP” can not find this BLE device.

Do I also need to do something?

Thank you,

Chianglin

RE: How to print UART message in "ble_app_uart" project in SDK15.2

Vidar Berg — Wed, 20 Mar 2019 09:20:08 GMT

Hi Chianglin,

You can change the pin numbers in uart_init(), but the UART pins will not be routed to the JLink chip then.

Best regards,

Vidar

RE: How to print UART message in "ble_app_uart" project in SDK15.2

chianglin — Wed, 20 Mar 2019 08:51:59 GMT

Hi Vidar,

I am using the EVM board like following image.

Yes, it can print debug message via "JLink CDC UART Port" to PC.

If I want to print debug message to other UART pin (for example: P0.06 for TXD and P0.08 for RXD), how to modify the source code to do this job?

Thank you,

Chianglin

RE: How to print UART message in "ble_app_uart" project in SDK15.2

Vidar Berg — Wed, 20 Mar 2019 06:55:11 GMT

Hi Chianglin,

Is this the Nordic devkit (nRF52 DK - PCA10040)? In that case, you shouldn't need to modify anything, UART data will be written to the JLINK CDC UART port (virtual com port) on your PC. You just need a serial client and select the correct COM port and baudrate (default 115200)

Best regards,

Vidar

RE: How to print UART message in "ble_app_uart" project in SDK15.2

chianglin — Tue, 19 Mar 2019 15:07:47 GMT

Hi Vidar,

I had try to use printf() to write data to UART, and the UART interface is connect to PC, but I can not find any data in PC console.

My environment is:

1. Use Nordic's nRF52832 EVM board.

2. Use "ble_app_uart" project of SDK15.2, and I doesn't modify any thing. Actually, there have "printf()" function in main.c.

But I still can not found any message from PC via UART interface.

How can I fix this problem?

Thank you,

Chianglin

RE: How to print UART message in "ble_app_uart" project in SDK15.2

Vidar Berg — Tue, 19 Mar 2019 14:37:17 GMT

Hi,

The ble_app_uart project prints debug messages over Segger RTT by default. But you can use printf() if you wish to write data to the UART.

Vidar