Serial port on the nRF52840 Dongle

[Jimmy@zone]

Hi I am trying to init the serial on the nRF52840 Dongle but there are some defines missing in the boards/pca10069.h

I run this on the nRF52840 DK and it works fine.

NRF_SERIAL_DRV_UART_CONFIG_DEF(m_uart0_drv_config,
    RX_PIN_NUMBER, TX_PIN_NUMBER,
    RTS_PIN_NUMBER, CTS_PIN_NUMBER,
    NRF_UART_HWFC_ENABLED, NRF_UART_PARITY_EXCLUDED,
    NRF_UART_BAUDRATE_115200,
    UART_DEFAULT_CONFIG_IRQ_PRIORITY);

file: boards/pca10056.h

#define RX_PIN_NUMBER  8
#define TX_PIN_NUMBER  6
#define CTS_PIN_NUMBER 7
#define RTS_PIN_NUMBER 5
#define HWFC           true

[Jørgen Holmefjord]

Hi,

There is no UART to USB bridge on the nRF52840 Dongle (the Segger debugger chip is used for that on the Development Kits), and therefore there is no default UART pins. 

You can use any pins for the UART peripheral, but it is recommended to stay away from the pins marked "low frequency I/O only" in the ball assignment documentation.

Also make sure that you choose some pins that is not used by other peripherals/components on the dongle, for instance P0.06 and P0.08 is used for LEDs.

If you are communicating with a PC, you can also setup the dongle with USB CDC ACM to send data through virtual USB COM port. There is an example available in the SDK.

Best regards,
Jørgen

[Jimmy@zone]

Is there a way to get the sample to run as a pure Serial device e.g not using any AT commands. I tried to change the APP_USBD_CDC_COMM_PROTOCOL_AT_V250 to APP_USBD_CDC_COMM_PROTOCOL_NONE but still there is no data sent when I trie to send it using the Linux 

_fd = open(_port.c_str(), O_RDWR | O_NOCTTY | O_SYNC);
    if (_fd < 0)
    {
        fprintf(stderr, "Error Failed to open post '%s' : %s\n", _port.c_str(), strerror(errno));
        return false;
    }
    
      struct termios tty;
    memset(&tty, 0, sizeof tty);
    if (tcgetattr(_fd, &tty) != 0)
    {
        fprintf(stderr, "Error failed to get attributs from serial %s\n", strerror(errno));
        return false;
    }
    fprintf(stdout, "Setting speed %d\n", speed);
    cfsetospeed(&tty, speed);
    cfsetispeed(&tty, speed);

    tty.c_cflag = (tty.c_cflag & ~CSIZE) | CS8; // 8-bit chars
    // disable IGNBRK for mismatched speed tests; otherwise receive break as \000 chars
    tty.c_iflag &= ~IGNBRK; // disable break processing
    tty.c_lflag = 0;        // no signaling chars, no echo,
                            // no canonical processing
    tty.c_oflag = 0;        // no remapping, no delays
    tty.c_cc[VMIN] = 0;     // read doesn't block
    tty.c_cc[VTIME] = 5;    // 0.5 seconds read timeout

    tty.c_iflag &= ~(IXON | IXOFF | IXANY); // shut off xon/xoff ctrl

    tty.c_cflag |= (CLOCAL | CREAD);   // ignore modem controls,
                                       // enable reading
    tty.c_cflag &= ~(PARENB | PARODD); // shut off parity
    tty.c_cflag |= parity;
    tty.c_cflag &= ~CSTOPB;
    tty.c_cflag &= ~CRTSCTS;

    if (tcsetattr(_fd, TCSANOW, &tty) != 0)
    {
        fprintf(stderr, "Error setting attributes on serail %s\n", strerror(errno));
        return false;
    }
    return true;
    
    
    write(_fd, "baja maja", strlen("baja maja"));

[awneil]

Jimmy@zone said:

run as a pure Serial device

Not quite sure what you mean by that?

Do you just want to send/receive stuff from/to the microcontroller locally via its UART pins?

Or are you talking about transferring stuff over BLE?

For the latter, see the Nordic UART Service (NUS) example ... 

[Jimmy@zone]

I am looking to send data from my PC to the DK or the Dongle using serial or any other mean of simple communication.

[Jørgen Holmefjord]

You should be able to use the example as a standard serial device with terminal software, for instance putty. Please have a look at the Terminal settings documentation to see the recommended settings.

[Jimmy@zone]

I want to do it thru a c program and not thru putty or minicom thy both work. I am guessing thy both use AT commands and I want to use a serial port with no protocol attached to it. Like the UART normal serial but that was not available on the dongle.

[Jimmy@zone]

Can this usb connection not be used ??? 

[awneil]

Jimmy@zone said:

I am guessing thy both use AT commands

No - PuTTY et al *are* (in effect, if not in actual fact) "just 'C' programs" - they just send the bytes you type to a COM port, and display the bytes they receive from the COM port.

So that's "all" (sic) your 'C' program would need to do.

See: devzone.nordicsemi.com/.../161825

Jimmy@zone said:

I want to use a serial port with no protocol

So you do want a wired connection, then?

In which case, see my earlier replies ...

[awneil]

Jimmy@zone said:

Can this usb connection not be used ?

We seem to be going round in circles here.

If you want to use that USB connection, then you will have to implement the USB CDC ACM on the nRF52840 - which you just said you didn't want to do?

[Jimmy@zone]

Missing bit to get the serial to work =) thanks for the help.

int bits;

    bits = 0;

ioctl(_fd, TIOCMGET, &bits);

printf("bits:%d\n", bits);

bits = TIOCM_DTR | TIOCM_RTS;

    ioctl( _fd, TIOCMSET, &bits );