nRF51 uart pin config

[shadowsky]

Hi everyone,

I pass few days to try to fix my issue whiteout success.

I'm working on UART example provide by SDK 10 and tried to set up a communication from my computer to the nRF51422 board. There is the code used:

#define RX_PIN_NUMBER 11
#define TX_PIN_NUMBER 9

void uart_error_handle(app_uart_evt_t * p_event) {
  uint8_t cr;
  switch(p_event->evt_type) {
    case APP_UART_DATA_READY:
      while(app_uart_get(&cr) != NRF_SUCCESS);
      SEGGER_RTT_printf(0, "%c", cr);
      break;
    default:
      break;
  }
}

int main(void) {
  uint32_t err_code;
  const app_uart_comm_params_t comm_params = 
  {
    RX_PIN_NUMBER,
    TX_PIN_NUMBER,
    RTS_PIN_NUMBER,
    CTS_PIN_NUMBER,
    APP_UART_FLOW_CONTROL_DISABLED,
    false,
    UART_BAUDRATE_BAUDRATE_Baud38400
  };

  APP_UART_FIFO_INIT(&comm_params,
    UART_RX_BUF_SIZE,
    UART_TX_BUF_SIZE,
    uart_error_handle,
    APP_IRQ_PRIORITY_LOW,
    err_code);
  APP_ERROR_CHECK(err_code);

  while (true);
  }
}

Everything works well with this settings and I can get the communication through the JTAG port, but is not what I want.

My problem happened when I modify :

#define RX_PIN_NUMBER 11
#define TX_PIN_NUMBER 9
/**** to ****/
#define RX_PIN_NUMBER 1
#define TX_PIN_NUMBER 2

Then I can't get anything else than an error. When I connect a wire to the pin P.01 the device restart again and again after APP_UART_FIFO_INIT. Even the TX from the Nordic device to my computer don't work with this configuration.

Thank for your help.

[shadowsky]

I found what was wrong and it's not from the code. My mistake was to thing UART and RS232 are the same protocol. Following this picture we can see the difference between them.