UART RX, App UART Fifo Not Calling Event Handler

[Nadeem]

Dear All,

I am using the example UART in Peripherals

I can send data easily but have problem in receiving data. When I try to receive data the UART Fifo Event handler is never called... I tried many things but it seems nothing is working..Looking at the scope I can see the signals coming, but what's weird is when I run the code on the BLE, the voltage of the signal shrinks..as you can see in the second picture.

Not sure if this is related to the issue.. We are using a rs485 to ttl converter. The transmit side is perfect , only have issues with receive side. PLEASE HELP URGENTLY

.

.

[Nadeem]

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/** @file
 * @defgroup uart_example_main main.c
 * @{
 * @ingroup uart_example
 * @brief UART Example Application main file.
 *
 * This file contains the source code for a sample application using UART.
 *
 */

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include "app_uart.h"
#include "app_error.h"
#include "nrf_delay.h"
#include "nrf.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#include "bsp.h"
#include "nrf_log.h"
#include "nrf_gpio.h"
#include "SEGGER_RTT_Conf.h"
#if defined (UART_PRESENT)
#include "nrf_uart.h"
#endif
#if defined (UARTE_PRESENT)
#include "nrf_uarte.h"
#endif


#define ENABLE_LOOPBACK_TEST  /**< if defined, then this example will be a loopback test, which means that TX should be connected to RX to get data loopback. */

#define MAX_TEST_DATA_BYTES     (30U)                /**< max number of test bytes to be used for tx and rx. */
#define UART_TX_BUF_SIZE 256                         /**< UART TX buffer size. */
#define UART_RX_BUF_SIZE 256                         /**< UART RX buffer size. */


/**@brief Function for initializing logging. */
static void log_init(void)
{
    ret_code_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


void uart_error_handle(app_uart_evt_t * p_event)
{
   ret_code_t err_code;
   static uint8_t data_array[256];
	static uint8_t index = 0;
    if (p_event->evt_type == APP_UART_COMMUNICATION_ERROR)
    {
         NRF_LOG_ERROR("Communication error occurred while handling UART: %08X", p_event->data.error_communication );
            if( p_event->data.error_communication & UART_ERRORSRC_BREAK_Msk )
            {
                NRF_LOG_ERROR("   Break");
            }
            if( p_event->data.error_communication & UART_ERRORSRC_FRAMING_Msk )
            {
                NRF_LOG_ERROR("   Framing");
            }
            if( p_event->data.error_communication & UART_ERRORSRC_PARITY_Msk )
            {
                NRF_LOG_ERROR("   Parity");
            }
            if( p_event->data.error_communication & UART_ERRORSRC_OVERRUN_Msk )
            {
                NRF_LOG_ERROR("   Overrun");
            }
        APP_ERROR_HANDLER(p_event->data.error_communication);
    }
    else if (p_event->evt_type == APP_UART_FIFO_ERROR)
    {
        APP_ERROR_HANDLER(p_event->data.error_code);
    }
     else if (p_event->evt_type == APP_UART_DATA_READY)
    {
      nrf_gpio_pin_set(16);
       UNUSED_VARIABLE(app_uart_get(&data_array[index]));
			index++;
      nrf_gpio_pin_clear(16);
			
   
    }
}


#ifdef ENABLE_LOOPBACK_TEST
/* Use flow control in loopback test. */
#define UART_HWFC APP_UART_FLOW_CONTROL_ENABLED

/** @brief Function for setting the @ref ERROR_PIN high, and then enter an infinite loop.
 */
static void show_error(void)
{

    bsp_board_leds_on();
    while (true)
    {
        // Do nothing.
    }
}


/** @brief Function for testing UART loop back.
 *  @details Transmitts one character at a time to check if the data received from the loopback is same as the transmitted data.
 *  @note  @ref TX_PIN_NUMBER must be connected to @ref RX_PIN_NUMBER)
 */
static void uart_send()
{
    uint8_t * tx_data = (uint8_t *)("Abcdefghijklmnopqrstuvw");
 
     nrf_gpio_pin_set(19);
     nrf_delay_ms(100);
 
    // Start sending one byte and see if you get the same
    for (uint32_t i = 0; i < MAX_TEST_DATA_BYTES; i++)
    {
        
        uint32_t err_code;
         
        while (app_uart_put(tx_data[i]) != NRF_SUCCESS);
        nrf_delay_ms(10);

    }
       nrf_gpio_pin_clear(19);
       nrf_delay_ms(50);
    return;
}


 
#else
/* When UART is used for communication with the host do not use flow control.*/
#define UART_HWFC APP_UART_FLOW_CONTROL_DISABLED
#endif


/**
 * @brief Function for main application entry.
 */
int main(void)
{
    uint32_t err_code;

//    bsp_board_init(BSP_INIT_LEDS);
    log_init();
       NRF_LOG_INFO("Uart Sample"); 
       nrf_delay_ms(1000);
        nrf_gpio_pin_clear(19);
       
    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,
#if defined (UART_PRESENT)
          NRF_UART_BAUDRATE_19200
#else
          NRF_UARTE_BAUDRATE_115200
#endif
      };

    APP_UART_FIFO_INIT(&comm_params,
                         UART_RX_BUF_SIZE,
                         UART_TX_BUF_SIZE,
                         uart_error_handle,
                         APP_IRQ_PRIORITY_LOWEST,
                         err_code);

    APP_ERROR_CHECK(err_code);
   nrf_gpio_cfg_output(19);
  //  nrf_gpio_cfg_output(16);
 //  nrf_gpio_cfg_input(4,NRF_GPIO_PIN_PULLDOWN);
 //  nrf_gpio_pin_clear(19);
#ifndef ENABLE_LOOPBACK_TEST
  printf("A");

    while (true)
    {
        uint8_t cr;
        while (app_uart_get(&cr) != NRF_SUCCESS);
        while (app_uart_put(cr) != NRF_SUCCESS);
        nrf_delay_ms(500);
          
        if (cr == 'q' || cr == 'Q')
        {
            printf(" \r\nExit!\r\n");

            while (true)
            {
                // Do nothing.
            }
        }
    }
#else
 
    // This part of the example is just for testing the loopback .
    while (true)
    {
        
    
        //nrf_delay_ms(500);
    }
#endif
}

[Nadeem]

The update on this is. Now i got to work but when i implement the same thing on the ble appp blinky example..i keep getting overrun errorwhen i send data too it.

The baud rate is same on both sides

[run_ar]

Hi,

What buffer size do you have? If you small buffers and no hw flow control the application won't be able to empty the buffers, as the BLE protocol will have higher priority tasks. please consider using hw flow control if possible.