ble_nus_data_send sending the wrong data

Hi,

I am writing a program that sends numbers counting up sequentially from my dev board to my phone on 500ms intervals. I used the ble_app_uart example as my base. I am trying to use the command ble_nus_data_send(&m_nus, up_counter, &length, m_conn_handle); to send the data to my phone. When I start the process, I can successfully send the string "Counting up." to my phone, but the counting numbers do not display properly. Instead, some unreadable text shows up on my phone; it looks like a problem when a device cannot interpret an ascii code. Does anyone know why I might be encountering this problem? For reference, my code and a screenshot of the output are posted below; the problem is on line 903.

/**
 * Copyright (c) 2014 - 2021, Nordic Semiconductor ASA
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
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 *    engineered, decompiled, modified and/or disassembled.
 *
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 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
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 */
/** @file
 *
 * @defgroup ble_sdk_uart_over_ble_main main.c
 * @{
 * @ingroup  ble_sdk_app_nus_eval
 * @brief    UART over BLE application main file.
 *
 * This file contains the source code for a sample application that uses the Nordic UART service.
 * This application uses the @ref srvlib_conn_params module.
 */


#include <stdint.h>
#include <string.h>
#include <time.h>

#include "nrf_delay.h"

#include "nordic_common.h"
#include "nrf.h"
#include "ble_hci.h"
#include "ble_advdata.h"
#include "ble_advertising.h"
#include "ble_conn_params.h"
#include "nrf_sdh.h"
#include "nrf_sdh_soc.h"
#include "nrf_sdh_ble.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_qwr.h"
#include "app_timer.h"
//#include "app_scheduler.h"
#include "nrf_drv_clock.h"
#include "ble_nus.h"
#include "app_uart.h"
#include "app_util_platform.h"
#include "bsp_btn_ble.h"
#include "nrf_pwr_mgmt.h"

#if defined (UART_PRESENT)
#include "nrf_uart.h"
#endif
#if defined (UARTE_PRESENT)
#include "nrf_uarte.h"
#endif

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

/*
#include "nrf_cli.h"
#include "nrf_cli_rtt.h"
#include "nrf_cli_types.h"
*/
#define APP_BLE_CONN_CFG_TAG            1                                           /**< A tag identifying the SoftDevice BLE configuration. */

#define DEVICE_NAME                     "Nordic_UART"                               /**< Name of device. Will be included in the advertising data. */
#define NUS_SERVICE_UUID_TYPE           BLE_UUID_TYPE_VENDOR_BEGIN                  /**< UUID type for the Nordic UART Service (vendor specific). */

#define APP_BLE_OBSERVER_PRIO           3                                           /**< Application's BLE observer priority. You shouldn't need to modify this value. */

#define APP_ADV_INTERVAL                64                                          /**< The advertising interval (in units of 0.625 ms. This value corresponds to 40 ms). */

#define APP_ADV_DURATION                18000                                       /**< The advertising duration (180 seconds) in units of 10 milliseconds. */

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(20, UNIT_1_25_MS)             /**< Minimum acceptable connection interval (20 ms), Connection interval uses 1.25 ms units. */
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(75, UNIT_1_25_MS)             /**< Maximum acceptable connection interval (75 ms), Connection interval uses 1.25 ms units. */
#define SLAVE_LATENCY                   0                                           /**< Slave latency. */
#define CONN_SUP_TIMEOUT                MSEC_TO_UNITS(4000, UNIT_10_MS)             /**< Connection supervisory timeout (4 seconds), Supervision Timeout uses 10 ms units. */
#define FIRST_CONN_PARAMS_UPDATE_DELAY  APP_TIMER_TICKS(5000)                       /**< Time from initiating event (connect or start of notification) to first time sd_ble_gap_conn_param_update is called (5 seconds). */
#define NEXT_CONN_PARAMS_UPDATE_DELAY   APP_TIMER_TICKS(30000)                      /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
#define MAX_CONN_PARAMS_UPDATE_COUNT    3                                           /**< Number of attempts before giving up the connection parameter negotiation. */

#define DEAD_BEEF                       0xDEADBEEF                                  /**< Value used as error code on stack dump, can be used to identify stack location on stack unwind. */

#define UART_TX_BUF_SIZE                256                                         /**< UART TX buffer size. */
#define UART_RX_BUF_SIZE                256                                         /**< UART RX buffer size. */

#define UP_HIGH_LIM 255
#define UP_LOW_LIM 0
#define UP_DELAY_TIME 50

#define DN_HIGH_LIM 1000
#define DN_LOW_LIM 1 
#define DN_DELAY_TIME 500
#define DELAY_TIME 500

BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT);                                   /**< BLE NUS service instance. */
NRF_BLE_GATT_DEF(m_gatt);                                                           /**< GATT module instance. */
NRF_BLE_QWR_DEF(m_qwr);                                                             /**< Context for the Queued Write module.*/
BLE_ADVERTISING_DEF(m_advertising);                                                 /**< Advertising module instance. */
APP_TIMER_DEF(m_repeated_timer_id);
APP_TIMER_DEF(m_single_shot_timer_id); 

uint8_t timer_flag = 0;
static uint16_t   m_conn_handle          = BLE_CONN_HANDLE_INVALID;                 /**< Handle of the current connection. */
static uint16_t   m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - 3;            /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
static ble_uuid_t m_adv_uuids[]          =                                          /**< Universally unique service identifier. */
{
    {BLE_UUID_NUS_SERVICE, NUS_SERVICE_UUID_TYPE}
};


/**@brief Function for assert macro callback.
 *
 * @details This function will be called in case of an assert in the SoftDevice.
 *
 * @warning This handler is an example only and does not fit a final product. You need to analyse
 *          how your product is supposed to react in case of Assert.
 * @warning On assert from the SoftDevice, the system can only recover on reset.
 *
 * @param[in] line_num    Line number of the failing ASSERT call.
 * @param[in] p_file_name File name of the failing ASSERT call.
 */
void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
{
    app_error_handler(DEAD_BEEF, line_num, p_file_name);
}

/**@brief Function for initializing the timer module.
 */
static void timers_init(void)
{
    ret_code_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
}

/**@brief Function starting the internal LFCLK oscillator.
 *
 * @details This is needed by RTC1 which is used by the Application Timer
 *          (When SoftDevice is enabled the LFCLK is always running and this is not needed).
 */
static void lfclk_request(void)
{
    ret_code_t err_code = nrf_drv_clock_init();
    APP_ERROR_CHECK(err_code);
    nrf_drv_clock_lfclk_request(NULL);
}

/**@brief Timeout handler for the repeated timer.
 */
static void repeated_timer_handler(void * p_context)
{
    //nrf_drv_gpiote_out_toggle(LED_1);
    //nrf_delay_ms(500);
    //app_timer_stop(m_repeated_timer_id);
    //timer_flag = 1;
    count_up();
}


/**@brief Timeout handler for the single shot timer.
 */
static void single_shot_timer_handler(void * p_context)
{
    //nrf_drv_gpiote_out_clear(LED_2);
    timer_flag = 1;
}

/**@brief Create timers.
 */
static void create_timers()
{
    ret_code_t err_code;

    // Create timers
    err_code = app_timer_create(&m_repeated_timer_id,
                                APP_TIMER_MODE_REPEATED,
                                repeated_timer_handler);
    APP_ERROR_CHECK(err_code);
}

/**@brief Function for the GAP initialization.
 *
 * @details This function will set up all the necessary GAP (Generic Access Profile) parameters of
 *          the device. It also sets the permissions and appearance.
 */

APP_SCHED_INIT(SCHED_MAX_EVENT_DATA_SIZE, SCHED_QUEUE_SIZE);

static void gap_params_init(void)
{
    uint32_t                err_code;
    ble_gap_conn_params_t   gap_conn_params;
    ble_gap_conn_sec_mode_t sec_mode;

    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

    err_code = sd_ble_gap_device_name_set(&sec_mode,
                                          (const uint8_t *) DEVICE_NAME,
                                          strlen(DEVICE_NAME));
    APP_ERROR_CHECK(err_code);

    memset(&gap_conn_params, 0, sizeof(gap_conn_params));

    gap_conn_params.min_conn_interval = MIN_CONN_INTERVAL;
    gap_conn_params.max_conn_interval = MAX_CONN_INTERVAL;
    gap_conn_params.slave_latency     = SLAVE_LATENCY;
    gap_conn_params.conn_sup_timeout  = CONN_SUP_TIMEOUT;

    err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling Queued Write Module errors.
 *
 * @details A pointer to this function will be passed to each service which may need to inform the
 *          application about an error.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void nrf_qwr_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@brief Function for handling the data from the Nordic UART Service.
 *
 * @details This function will process the data received from the Nordic UART BLE Service and send
 *          it to the UART module.
 *
 * @param[in] p_evt       Nordic UART Service event.
 */
/**@snippet [Handling the data received over BLE] */
static void nus_data_handler(ble_nus_evt_t * p_evt)
{
    NRF_LOG_DEBUG("NUS data handler.");

    uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
    uint8_t b[BLE_NUS_MAX_DATA_LEN];

    if (p_evt->type == BLE_NUS_EVT_RX_DATA)
    {
        uint32_t err_code;

        NRF_LOG_DEBUG("Received data from BLE NUS. Writing data on UART.");
        NRF_LOG_HEXDUMP_DEBUG(p_evt->params.rx_data.p_data, p_evt->params.rx_data.length);
        for (uint32_t i = 0; i < p_evt->params.rx_data.length; i++)
        {
            //b[i] = app_uart_get(&data_array[i]);
            b[i] = app_uart_get(&data_array[i]);
            do
            {
                err_code = app_uart_put(p_evt->params.rx_data.p_data[i]);
                if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", err_code);
                    APP_ERROR_CHECK(err_code);
                }
            } while (err_code == NRF_ERROR_BUSY);
        }
        if (p_evt->params.rx_data.p_data[p_evt->params.rx_data.length - 1] == '\r')
        {
            while (app_uart_put('\n') == NRF_ERROR_BUSY);
        }
        if((memcmp(p_evt->params.rx_data.p_data,"0x01", p_evt->params.rx_data.length) == 0))
        {
            NRF_LOG_DEBUG("Sending response.");
            
            char a[BLE_NUS_MAX_DATA_LEN] = "Counting up.";
            int length = BLE_NUS_MAX_DATA_LEN;

            ble_nus_data_send(&m_nus, a, &length, m_conn_handle);

            uint32_t time_err_code;
            static uint32_t timeout = 0;
            NRF_LOG_DEBUG("TX data ready.");

            for(int i = 0; i <= 255; ++i)
            {
                timeout += 500;
                time_err_code = app_timer_start(m_repeated_timer_id, APP_TIMER_TICKS(timeout), NULL);
                //count_up((uint8_t *)i);
            }
        }else if((memcmp(p_evt->params.rx_data.p_data,"0x02", p_evt->params.rx_data.length) == 0))
        {
            NRF_LOG_DEBUG("Sending response.");
            char a[BLE_NUS_MAX_DATA_LEN] = "Counting down.";
            int length = BLE_NUS_MAX_DATA_LEN;

            //ble_nus_data_send(&m_nus, a, &length, m_conn_handle);
        }

    }

}


/**@snippet [Handling the data received over BLE] */


/**@brief Function for initializing services that will be used by the application.
 */
static void services_init(void)
{
    uint32_t           err_code;
    ble_nus_init_t     nus_init;
    nrf_ble_qwr_init_t qwr_init = {0};

    // Initialize Queued Write Module.
    qwr_init.error_handler = nrf_qwr_error_handler;

    err_code = nrf_ble_qwr_init(&m_qwr, &qwr_init);
    APP_ERROR_CHECK(err_code);

    // Initialize NUS.
    memset(&nus_init, 0, sizeof(nus_init));

    nus_init.data_handler = nus_data_handler;

    err_code = ble_nus_init(&m_nus, &nus_init);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling an event from the Connection Parameters Module.
 *
 * @details This function will be called for all events in the Connection Parameters Module
 *          which are passed to the application.
 *
 * @note All this function does is to disconnect. This could have been done by simply setting
 *       the disconnect_on_fail config parameter, but instead we use the event handler
 *       mechanism to demonstrate its use.
 *
 * @param[in] p_evt  Event received from the Connection Parameters Module.
 */
static void on_conn_params_evt(ble_conn_params_evt_t * p_evt)
{
    uint32_t err_code;

    if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED)
    {
        err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
        APP_ERROR_CHECK(err_code);
    }
}


/**@brief Function for handling errors from the Connection Parameters module.
 *
 * @param[in] nrf_error  Error code containing information about what went wrong.
 */
static void conn_params_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@brief Function for initializing the Connection Parameters module.
 */
static void conn_params_init(void)
{
    uint32_t               err_code;
    ble_conn_params_init_t cp_init;

    memset(&cp_init, 0, sizeof(cp_init));

    cp_init.p_conn_params                  = NULL;
    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
    cp_init.start_on_notify_cccd_handle    = BLE_GATT_HANDLE_INVALID;
    cp_init.disconnect_on_fail             = false;
    cp_init.evt_handler                    = on_conn_params_evt;
    cp_init.error_handler                  = conn_params_error_handler;

    err_code = ble_conn_params_init(&cp_init);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for putting the chip into sleep mode.
 *
 * @note This function will not return.
 */
static void sleep_mode_enter(void)
{
    uint32_t err_code = bsp_indication_set(BSP_INDICATE_IDLE);
    APP_ERROR_CHECK(err_code);

    // Prepare wakeup buttons.
    err_code = bsp_btn_ble_sleep_mode_prepare();
    APP_ERROR_CHECK(err_code);

    // Go to system-off mode (this function will not return; wakeup will cause a reset).
    err_code = sd_power_system_off();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling advertising events.
 *
 * @details This function will be called for advertising events which are passed to the application.
 *
 * @param[in] ble_adv_evt  Advertising event.
 */
static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
{
    uint32_t err_code;

    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
            err_code = bsp_indication_set(BSP_INDICATE_ADVERTISING);
            APP_ERROR_CHECK(err_code);
            break;
        case BLE_ADV_EVT_IDLE:
            sleep_mode_enter();
            break;
        default:
            break;
    }
}


/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
volatile uint8_t m_last_successful_conn_handle = 0;
static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    uint32_t err_code;
    NRF_LOG_INFO("BLE event handler.");

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            NRF_LOG_INFO("Connected");
            err_code = bsp_indication_set(BSP_INDICATE_CONNECTED);
            APP_ERROR_CHECK(err_code);
            m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
            err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr, m_conn_handle);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected");
            // LED indication will be changed when advertising starts.
            m_conn_handle = BLE_CONN_HANDLE_INVALID;
            break;

        /*case BLE_GATTS_EVT_HVN_TX_COMPLETE:
        {
            uint32_t time_err_code;
            static uint32_t timeout = 0;
            NRF_LOG_DEBUG("TX data ready.");

            for(int i = 0; i <= 255; ++i)
            {
                timeout += 500;
                time_err_code = app_timer_start(m_repeated_timer_id, APP_TIMER_TICKS(timeout), NULL);
                //count_up((uint8_t *)i);
            }
        } break;*/
        
        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_INFO("PHY update request.");
            ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
            err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
            // Pairing not supported
            NRF_LOG_INFO("Pairing not supported.");
            err_code = sd_ble_gap_sec_params_reply(m_conn_handle, BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP, NULL, NULL);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_SYS_ATTR_MISSING:
            // No system attributes have been stored.
            NRF_LOG_INFO("No system attributes have been stored.");
            err_code = sd_ble_gatts_sys_attr_set(m_conn_handle, NULL, 0, 0);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            NRF_LOG_INFO("Timeout from client.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_TIMEOUT:
            // Disconnect on GATT Server timeout event.
            NRF_LOG_INFO("Timeout from server.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for the SoftDevice initialization.
 *
 * @details This function initializes the SoftDevice and the BLE event interrupt.
 */
static void ble_stack_init(void)
{
    ret_code_t err_code;

    err_code = nrf_sdh_enable_request();
    APP_ERROR_CHECK(err_code);

    // Configure the BLE stack using the default settings.
    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
    APP_ERROR_CHECK(err_code);

    // Enable BLE stack.
    err_code = nrf_sdh_ble_enable(&ram_start);
    APP_ERROR_CHECK(err_code);

    // Register a handler for BLE events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
}


/**@brief Function for handling events from the GATT library. */
void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
{
    if ((m_conn_handle == p_evt->conn_handle) && (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED))
    {
        m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
        NRF_LOG_INFO("Data len is set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
    }
    NRF_LOG_DEBUG("ATT MTU exchange completed. central 0x%x peripheral 0x%x",
                  p_gatt->att_mtu_desired_central,
                  p_gatt->att_mtu_desired_periph);
}


/**@brief Function for initializing the GATT library. */
void gatt_init(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling events from the BSP module.
 *
 * @param[in]   event   Event generated by button press.
 */
void bsp_event_handler(bsp_event_t event)
{
    uint32_t err_code;
    switch (event)
    {
        case BSP_EVENT_SLEEP:
            sleep_mode_enter();
            break;

        case BSP_EVENT_DISCONNECT:
            err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            if (err_code != NRF_ERROR_INVALID_STATE)
            {
                APP_ERROR_CHECK(err_code);
            }
            break;

        case BSP_EVENT_WHITELIST_OFF:
            if (m_conn_handle == BLE_CONN_HANDLE_INVALID)
            {
                err_code = ble_advertising_restart_without_whitelist(&m_advertising);
                if (err_code != NRF_ERROR_INVALID_STATE)
                {
                    APP_ERROR_CHECK(err_code);
                }
            }
            break;

        default:
            break;
    }
}


/**@brief   Function for handling app_uart events.
 *
 * @details This function will receive a single character from the app_uart module and append it to
 *          a string. The string will be be sent over BLE when the last character received was a
 *          'new line' '\n' (hex 0x0A) or if the string has reached the maximum data length.
 */
/**@snippet [Handling the data received over UART] */
void uart_event_handle(app_uart_evt_t * p_event)
{
    static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
    static uint8_t index = 0;
    uint32_t       err_code;
    
    NRF_LOG_INFO("UART event handler.");

    switch (p_event->evt_type)
    {
        case APP_UART_DATA_READY:
            NRF_LOG_INFO("Data is ready.");
            UNUSED_VARIABLE(app_uart_get(&data_array[index]));
            index++;

            if ((data_array[index - 1] == '\n') ||
                (data_array[index - 1] == '\r') ||
                (index >= m_ble_nus_max_data_len))
            {
                if (index > 1)
                {
                    NRF_LOG_DEBUG("Ready to send data over BLE NUS");
                    NRF_LOG_HEXDUMP_DEBUG(data_array, index);

                    do
                    {
                        uint16_t length = (uint16_t)index;
                        err_code = ble_nus_data_send(&m_nus, data_array, &length, m_conn_handle);
                        if ((err_code != NRF_ERROR_INVALID_STATE) &&
                            (err_code != NRF_ERROR_RESOURCES) &&
                            (err_code != NRF_ERROR_NOT_FOUND))
                        {
                            APP_ERROR_CHECK(err_code);
                        }
                    } while (err_code == NRF_ERROR_RESOURCES);
                }
                
                index = 0;
            }
            break;

        case APP_UART_COMMUNICATION_ERROR:
            NRF_LOG_INFO("App UART communicatino error.");
            APP_ERROR_HANDLER(p_event->data.error_communication);
            break;

        case APP_UART_FIFO_ERROR:
            NRF_LOG_INFO("App UART FIFO error.");
            APP_ERROR_HANDLER(p_event->data.error_code);
            break;

        default:
            break;
    }
}
/**@snippet [Handling the data received over UART] */


/**@brief  Function for initializing the UART module.
 */
/**@snippet [UART Initialization] */
static void uart_init(void)
{
    uint32_t                     err_code;
    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
    };

    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);
}
/**@snippet [UART Initialization] */


/**@brief Function for initializing the Advertising functionality.
 */
static void advertising_init(void)
{
    uint32_t               err_code;
    ble_advertising_init_t init;

    memset(&init, 0, sizeof(init));

    init.advdata.name_type          = BLE_ADVDATA_FULL_NAME;
    init.advdata.include_appearance = false;
    init.advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;

    init.srdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    init.srdata.uuids_complete.p_uuids  = m_adv_uuids;

    init.config.ble_adv_fast_enabled  = true;
    init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
    init.config.ble_adv_fast_timeout  = APP_ADV_DURATION;
    init.evt_handler = on_adv_evt;

    err_code = ble_advertising_init(&m_advertising, &init);
    APP_ERROR_CHECK(err_code);

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}


/**@brief Function for initializing buttons and leds.
 *
 * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to wake the application up.
 */
static void buttons_leds_init(bool * p_erase_bonds)
{
    bsp_event_t startup_event;

    uint32_t err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, bsp_event_handler);
    APP_ERROR_CHECK(err_code);

    err_code = bsp_btn_ble_init(NULL, &startup_event);
    APP_ERROR_CHECK(err_code);

    *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}


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

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


/**@brief Function for initializing power management.
 */
static void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the idle state (main loop).
 *
 * @details If there is no pending log operation, then sleep until next the next event occurs.
 */
static void idle_state_handle(void)
{
    if (NRF_LOG_PROCESS() == false)
    {
        nrf_pwr_mgmt_run();
    }
    
}
/*
static void cli_process(void)
{
#if CLI_OVER_USB_CDC_ACM
    nrf_cli_process(&m_cli_cdc_acm);
#endif

#if CLI_OVER_UART
    nrf_cli_process(&m_cli_uart);
#endif

    nrf_cli_process(&m_cli_rtt);
}*/

/**@brief Function for starting advertising.
 */
static void advertising_start(void)
{
    uint32_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
    APP_ERROR_CHECK(err_code);
}

/*
void write_response(char message);
void count_up(void);
static void count_dn();

void write_response(char message)
{
    
    if (message == '0x01')
    {
        count_up();
    }else if (message == '0x02')
    {
        count_dn();
    }else
    {
        printf("%c\n", message);
        NRF_LOG_INFO("Your message is: %c",message);
    }
}

void count_up(void)
{
    for(int i = UP_LOW_LIM; i <= UP_HIGH_LIM; ++i)
    {
        NRF_LOG_DEBUG("%d", i);
        sleep(2);

    } 
}

static void count_dn()
{
    for(int i = DN_HIGH_LIM; i >= UP_LOW_LIM; --i)
    {
        printf("%d", i);
        //delay(DN_DELAY_TIME);

    }
}

void delay(int number_of_milliseconds);

void delay(int number_of_milliseconds)
{
    // Storing start time
    clock_t start_time = clock();

    // looping while required time is not achieved
    while(clock() < start_time + number_of_milliseconds)
        ;
}*/
void count_up();
uint8_t up_counter = 0;

void count_up()
{
    int length = BLE_NUS_MAX_DATA_LEN;
    ble_conn_state_conn_handle_list_t conn_handles = ble_conn_state_periph_handles();
    uint32_t err_code;
    //uint32_t time_err_code;
    //static uint32_t timeout = 0;
    

    for (uint8_t i=m_last_successful_conn_handle; i<conn_handles.len; i++)
    {
        err_code = ble_nus_data_send(&m_nus, up_counter, &length, m_conn_handle);
        NRF_LOG_DEBUG("%d", up_counter);

        if(err_code == NRF_SUCCESS)
        {
            m_last_successful_conn_handle++;
        }
        else if (err_code == NRF_ERROR_RESOURCES)
        {
            // Queue is full. Break the loop, and countinue with the m_last_successful_conn_handle after TX_COMPLETE
            break;
        }
        
    }
    
    if (m_last_successful_conn_handle == conn_handles.len)
    {
        m_last_successful_conn_handle = 0;
    }

    if(up_counter == 255)
    {
        up_counter == 0;
    } else
    {
        up_counter++;
    }
}

/**@brief Application main function.
 */
int main(void)
{
    bool erase_bonds;

    // Initialize.
    uart_init();
    log_init();
    timers_init();
    lfclk_request();
    create_timers();
    //app_sched_execute();
    buttons_leds_init(&erase_bonds);
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    services_init();
    advertising_init();
    conn_params_init();

    // Start execution.
    printf("\r\nUART started.\r\n");
    NRF_LOG_INFO("Debug logging for UART over RTT started.");
    advertising_start();

    // Enter main loop.
    for (;;)
    {
        idle_state_handle();

        if(timer_flag)
        {
            // Run code previously in timeout handler
            //timer_flag = 0;
            
        }
    }
}


/**
 * @}
 */

Thank you

Parents
  • Hi,

    Your up_counter is an uint8_t, starting from 0. So you are sending raw numbers, not ascii characters. When the receiver prints these as if they were ascii characters, that will result in a lot of strange charcters and is expected. I assume what you want to do is send an ascii representatnion of th enumber? If so, use snprintf() or itoa() or similar to convert it to a string before sending it with ble_nus_data_send().

Reply
  • Hi,

    Your up_counter is an uint8_t, starting from 0. So you are sending raw numbers, not ascii characters. When the receiver prints these as if they were ascii characters, that will result in a lot of strange charcters and is expected. I assume what you want to do is send an ascii representatnion of th enumber? If so, use snprintf() or itoa() or similar to convert it to a string before sending it with ble_nus_data_send().

Children
  • Thank you for answering. I have tried to implement the itoa function, but it doesnt seem to be working. The output to my phone still looks the same. I even tried to look at the output in the debugger, and it's also incorrect. I posted my code and the debugger output below. Do you see whether I did something wrong?

    void count_up();
    int up_counter = 0;
    
    void count_up()
    {
        int length = BLE_NUS_MAX_DATA_LEN;
        ble_conn_state_conn_handle_list_t conn_handles = ble_conn_state_periph_handles();
        uint32_t err_code;
        char counter_char[sizeof(int)*8+1];
        //uint32_t time_err_code;
        //static uint32_t timeout = 0;
        
    
        for (uint8_t i=m_last_successful_conn_handle; i<conn_handles.len; i++)
        {
            itoa(up_counter, counter_char, 10);
            NRF_LOG_DEBUG("Converted String: %c", counter_char);
            err_code = ble_nus_data_send(&m_nus, counter_char, &length, m_conn_handle);
    
            if(err_code == NRF_SUCCESS)
            {
                m_last_successful_conn_handle++;
            }
            else if (err_code == NRF_ERROR_RESOURCES)
            {
                // Queue is full. Break the loop, and countinue with the m_last_successful_conn_handle after TX_COMPLETE
                break;
            }
            
        }
        
        if (m_last_successful_conn_handle == conn_handles.len)
        {
            m_last_successful_conn_handle = 0;
        }
    
        if(up_counter == 255)
        {
            up_counter == 0;
        } else
        {
            up_counter++;
        }
    }

    Thank you.

    Edit: removed a line from the code that was obviously wrong. The output is still the same, unfortunately.

  • I think I have it solved now. In the line ble_nus_data_send(&m_nus, counter_char, &length, m_conn_handle), length was set to BLE_NUS_MAX_DATA_LEN, which is some large number. I set length to 4 (the program should terminate before the counter reaches 1000), and the output is correct as far as I know. My code is posted below for reference.

    void count_up();
    volatile int up_counter = 0;
    
    void count_up()
    {
        //int length = BLE_NUS_MAX_DATA_LEN;
        int length = 4;
        ble_conn_state_conn_handle_list_t conn_handles = ble_conn_state_periph_handles();
        uint32_t err_code;
        char counter_char[20];
        //uint32_t time_err_code;
        //static uint32_t timeout = 0;
        
    
        for (uint8_t i=m_last_successful_conn_handle; i<conn_handles.len; i++)
        {
            itoa(up_counter, counter_char, 10);
            //NRF_LOG_DEBUG("Integer: %d   Converted String: %c\n", up_counter, counter_char);
            err_code = ble_nus_data_send(&m_nus, counter_char, &length, m_conn_handle);
    
            if(err_code == NRF_SUCCESS)
            {
                m_last_successful_conn_handle++;
            }
            else if (err_code == NRF_ERROR_RESOURCES)
            {
                // Queue is full. Break the loop, and countinue with the m_last_successful_conn_handle after TX_COMPLETE
                break;
            }
            //err_code = ble_nus_data_send(&m_nus, up_counter, &length, m_conn_handle);
            
        }
        
        if (m_last_successful_conn_handle == conn_handles.len)
        {
            m_last_successful_conn_handle = 0;
        }
    
        if(up_counter == 255)
        {
            up_counter == 0;
        } else
        {
            up_counter++;
        }
    }

    Thank you for your help.

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