app_usbd_cdc_acm_write multiple write

[kleanthise]

Hello i am using an nrf52840 s140 and i am trying to write a specific event when takes place to the usb port. I am using the usbd_uart example. 

It works fine for the first write command but when i am trying to write for a second time it just writes random stuff.

i am basically updating the value of a characteristic using a counter and i would like that value of the counter to be transferred over to usb virtual port

Looking forward for your help on this

#include "sdk_common.h"
#if NRF_MODULE_ENABLED(BLE_NUS)
#include "ble.h"
#include "ble_nus_custom.h"
#include "ble_srv_common.h"

#define NRF_LOG_MODULE_NAME ble_nus
#if BLE_NUS_CONFIG_LOG_ENABLED
#define NRF_LOG_LEVEL BLE_NUS_CONFIG_LOG_LEVEL
#define NRF_LOG_INFO_COLOR BLE_NUS_CONFIG_INFO_COLOR
#define NRF_LOG_DEBUG_COLOR BLE_NUS_CONFIG_DEBUG_COLOR
#else // BLE_NUS_CONFIG_LOG_ENABLED
#define NRF_LOG_LEVEL 0
#endif // BLE_NUS_CONFIG_LOG_ENABLED
#include "nrf_log.h"
NRF_LOG_MODULE_REGISTER();

#define BLE_UUID_NUS_TX_CHARACTERISTIC 0x0003 /**< The UUID of the TX Characteristic. */
#define BLE_UUID_NUS_RX_CHARACTERISTIC 0x0002 /**< The UUID of the RX Characteristic. */
#define PROGRESS_VALUE_CHAR_UUID 0x0004	      /**< The UUID for Progress Characteristic */
#define RESULTS_VALUE_CHAR_UUID 0x0005	      /**< The UUID for Results Characteristic */

#define BLE_NUS_MAX_RX_CHAR_LEN BLE_NUS_MAX_DATA_LEN /**< Maximum length of the RX Characteristic (in bytes). */
#define BLE_NUS_MAX_TX_CHAR_LEN BLE_NUS_MAX_DATA_LEN /**< Maximum length of the TX Characteristic (in bytes). */

#define NUS_BASE_UUID                                                                                                  \
	{                                                                                                              \
		{                                                                                                      \
			0x9E, 0xCA, 0xDC, 0x24, 0x0E, 0xE5, 0xA9, 0xE0, 0x93, 0xF3, 0xA3, 0xB5, 0x00, 0x00, 0x40, 0x6E \
		}                                                                                                      \
	} /**< Used vendor specific UUID. */

/**@brief Function for handling the @ref BLE_GAP_EVT_CONNECTED event from the SoftDevice.
 *
 * @param[in] p_nus     Nordic UART Service structure.
 * @param[in] p_ble_evt Pointer to the event received from BLE stack.
 */
static void on_connect(ble_nus_t *p_nus, ble_evt_t const *p_ble_evt)
{
	ret_code_t err_code;
	ble_nus_evt_t evt;
	ble_gatts_value_t gatts_val;
	uint8_t cccd_value[2];
	ble_nus_client_context_t *p_client = NULL;

	err_code = blcm_link_ctx_get(p_nus->p_link_ctx_storage,
	    p_ble_evt->evt.gap_evt.conn_handle,
	    (void *)&p_client);
	if (err_code != NRF_SUCCESS) {
		NRF_LOG_ERROR("Link context for 0x%02X connection handle could not be fetched.",
		    p_ble_evt->evt.gap_evt.conn_handle);
	}

	/* Check the hosts CCCD value to inform of readiness to send data using the RX characteristic */
	memset(&gatts_val, 0, sizeof(ble_gatts_value_t));
	gatts_val.p_value = cccd_value;
	gatts_val.len = sizeof(cccd_value);
	gatts_val.offset = 0;

	err_code = sd_ble_gatts_value_get(p_ble_evt->evt.gap_evt.conn_handle,
	    p_nus->tx_handles.cccd_handle,
	    &gatts_val);

	if ((err_code == NRF_SUCCESS) &&
	    (p_nus->data_handler != NULL) &&
	    ble_srv_is_notification_enabled(gatts_val.p_value)) {
		if (p_client != NULL) {
			p_client->is_notification_enabled = true;
		}

		memset(&evt, 0, sizeof(ble_nus_evt_t));
		evt.type = BLE_NUS_EVT_COMM_STARTED;
		evt.p_nus = p_nus;
		evt.conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
		evt.p_link_ctx = p_client;

		p_nus->data_handler(&evt);
	}
}

/**@brief Function for handling the @ref BLE_GATTS_EVT_WRITE event from the SoftDevice.
 *
 * @param[in] p_nus     Nordic UART Service structure.
 * @param[in] p_ble_evt Pointer to the event received from BLE stack.
 */
static void on_write(ble_nus_t *p_nus, ble_evt_t const *p_ble_evt)
{
	ret_code_t err_code;
	ble_nus_evt_t evt;
	ble_nus_client_context_t *p_client;
	ble_gatts_evt_write_t const *p_evt_write = &p_ble_evt->evt.gatts_evt.params.write;

	err_code = blcm_link_ctx_get(p_nus->p_link_ctx_storage,
	    p_ble_evt->evt.gatts_evt.conn_handle,
	    (void *)&p_client);
	if (err_code != NRF_SUCCESS) {
		NRF_LOG_ERROR("Link context for 0x%02X connection handle could not be fetched.",
		    p_ble_evt->evt.gatts_evt.conn_handle);
	}

	memset(&evt, 0, sizeof(ble_nus_evt_t));
	evt.p_nus = p_nus;
	evt.conn_handle = p_ble_evt->evt.gatts_evt.conn_handle;
	evt.p_link_ctx = p_client;

	if ((p_evt_write->handle == p_nus->tx_handles.cccd_handle) &&
	    (p_evt_write->len == 2)) {
		if (p_client != NULL) {
			if (ble_srv_is_notification_enabled(p_evt_write->data)) {
				p_client->is_notification_enabled = true;
				evt.type = BLE_NUS_EVT_COMM_STARTED;
			} else {
				p_client->is_notification_enabled = false;
				evt.type = BLE_NUS_EVT_COMM_STOPPED;
			}

			if (p_nus->data_handler != NULL) {
				p_nus->data_handler(&evt);
			}
		}
	} else if ((p_evt_write->handle == p_nus->rx_handles.value_handle) &&
		   (p_nus->data_handler != NULL)) {
		evt.type = BLE_NUS_EVT_RX_DATA;
		evt.params.rx_data.p_data = p_evt_write->data;
		evt.params.rx_data.length = p_evt_write->len;

		p_nus->data_handler(&evt);
	} else {
		// Do Nothing. This event is not relevant for this service.
	}
}

/**@brief Function for handling the @ref BLE_GATTS_EVT_HVN_TX_COMPLETE event from the SoftDevice.
 *
 * @param[in] p_nus     Nordic UART Service structure.
 * @param[in] p_ble_evt Pointer to the event received from BLE stack.
 */
static void on_hvx_tx_complete(ble_nus_t *p_nus, ble_evt_t const *p_ble_evt)
{
	ret_code_t err_code;
	ble_nus_evt_t evt;
	ble_nus_client_context_t *p_client;

	err_code = blcm_link_ctx_get(p_nus->p_link_ctx_storage,
	    p_ble_evt->evt.gatts_evt.conn_handle,
	    (void *)&p_client);
	if (err_code != NRF_SUCCESS) {
		NRF_LOG_ERROR("Link context for 0x%02X connection handle could not be fetched.",
		    p_ble_evt->evt.gatts_evt.conn_handle);
		return;
	}

	if ((p_client->is_notification_enabled) && (p_nus->data_handler != NULL)) {
		memset(&evt, 0, sizeof(ble_nus_evt_t));
		evt.type = BLE_NUS_EVT_TX_RDY;
		evt.p_nus = p_nus;
		evt.conn_handle = p_ble_evt->evt.gatts_evt.conn_handle;
		evt.p_link_ctx = p_client;

		p_nus->data_handler(&evt);
	}
}

void ble_nus_on_ble_evt(ble_evt_t const *p_ble_evt, void *p_context)
{
	if ((p_context == NULL) || (p_ble_evt == NULL)) {
		return;
	}

	ble_nus_t *p_nus = (ble_nus_t *)p_context;

	switch (p_ble_evt->header.evt_id) {
	case BLE_GAP_EVT_CONNECTED:
		on_connect(p_nus, p_ble_evt);
		break;

	case BLE_GATTS_EVT_WRITE:
		on_write(p_nus, p_ble_evt);
		break;

	case BLE_GATTS_EVT_HVN_TX_COMPLETE:
		on_hvx_tx_complete(p_nus, p_ble_evt);
		break;

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

// Add the RX Characteristic.

static uint32_t rx_char_add(ble_nus_t *p_nus, const ble_nus_init_t *p_nus_init)
{
	uint32_t err_code;
	ble_gatts_char_md_t char_md;
	ble_gatts_attr_md_t cccd_md;
	ble_gatts_attr_md_t attr_md;
	ble_gatts_attr_t attr_char_value;
	ble_uuid_t ble_uuid;

	// Initiliaze the structures
	memset(&cccd_md, 0, sizeof(cccd_md));
	memset(&char_md, 0, sizeof(char_md));
	memset(&attr_md, 0, sizeof(attr_md));
	memset(&attr_char_value, 0, sizeof(attr_char_value));

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);

	// Client Characteristic Configuration Descriptor metadata.
	cccd_md.vloc = BLE_GATTS_VLOC_STACK; // decide where to store the descriptor (the value of the CCCD), and once again we store it in the SoftDevice controlled part of memory (as we did with the characteristic)
	char_md.char_props.read = 0;	     // Enable read
	char_md.char_props.write = 1;	     // Enable write
	char_md.char_props.write_wo_resp = 1;
	char_md.char_props.notify = 0; // Enable notifications
	char_md.p_char_user_desc = NULL;
	char_md.p_char_pf = NULL;
	char_md.p_user_desc_md = NULL;
	char_md.p_cccd_md = &cccd_md;

	char_md.p_sccd_md = NULL;

	ble_uuid.type = p_nus->uuid_type;
	ble_uuid.uuid = BLE_UUID_NUS_RX_CHARACTERISTIC;

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm);

	attr_md.read_perm = p_nus_init->rx_char_attr_md.read_perm;
	attr_md.write_perm = p_nus_init->rx_char_attr_md.write_perm;
	attr_md.vloc = BLE_GATTS_VLOC_STACK; // BLE_GATTS_VLOC_STACK is the memory location (stack memory) to store the attributes (characteristic)
	attr_md.rd_auth = 0;
	attr_md.wr_auth = 0;
	attr_md.vlen = 0;

	attr_char_value.p_uuid = &ble_uuid;
	attr_char_value.p_attr_md = &attr_md;
	attr_char_value.init_len = sizeof(uint8_t); // sizeof(uint8_t);
	attr_char_value.init_offs = 0;
	attr_char_value.max_len = BLE_NUS_MAX_RX_CHAR_LEN; // sizeof(uint8_t);

	err_code = sd_ble_gatts_characteristic_add(p_nus->service_handle, &char_md, &attr_char_value, &p_nus->rx_handles);
	if (err_code != NRF_SUCCESS) {
		return err_code;
	}

	return NRF_SUCCESS;
}

// Add the TX Characteristic.

static uint32_t tx_char_add(ble_nus_t *p_nus, const ble_nus_init_t *p_nus_init)
{
	uint32_t err_code;
	ble_gatts_char_md_t char_md;
	ble_gatts_attr_md_t cccd_md;
	ble_gatts_attr_md_t attr_md;
	ble_gatts_attr_t attr_char_value;
	ble_uuid_t ble_uuid;

	// Initiliaze the structures
	memset(&cccd_md, 0, sizeof(cccd_md));
	memset(&char_md, 0, sizeof(char_md));
	memset(&attr_md, 0, sizeof(attr_md));
	memset(&attr_char_value, 0, sizeof(attr_char_value));

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);

	// Client Characteristic Configuration Descriptor metadata.
	cccd_md.vloc = BLE_GATTS_VLOC_STACK; // decide where to store the descriptor (the value of the CCCD), and once again we store it in the SoftDevice controlled part of memory (as we did with the characteristic)
	char_md.char_props.read = 1;	     // Enable read
	char_md.char_props.notify = 1;	     // Enable notifications
	char_md.p_char_user_desc = NULL;
	char_md.p_char_pf = NULL;
	char_md.p_user_desc_md = NULL;
	char_md.p_cccd_md = &cccd_md;

	char_md.p_sccd_md = NULL;

	ble_uuid.type = p_nus->uuid_type;
	ble_uuid.uuid = BLE_UUID_NUS_TX_CHARACTERISTIC;

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm);

	attr_md.read_perm = p_nus_init->tx_char_attr_md.read_perm;
	attr_md.write_perm = p_nus_init->tx_char_attr_md.write_perm;
	attr_md.vloc = BLE_GATTS_VLOC_STACK; // BLE_GATTS_VLOC_STACK is the memory location (stack memory) to store the attributes (characteristic)
	attr_md.rd_auth = 0;
	attr_md.wr_auth = 0;
	attr_md.vlen = 0;

	attr_char_value.p_uuid = &ble_uuid;
	attr_char_value.p_attr_md = &attr_md;
	attr_char_value.init_len = sizeof(uint8_t); // sizeof(uint8_t);
	attr_char_value.init_offs = 0;
	attr_char_value.max_len = BLE_NUS_MAX_TX_CHAR_LEN; // sizeof(uint8_t);

	err_code = sd_ble_gatts_characteristic_add(p_nus->service_handle, &char_md, &attr_char_value, &p_nus->tx_handles);
	if (err_code != NRF_SUCCESS) {
		return err_code;
	}

	return NRF_SUCCESS;
}

// Add the Progress Characteristic.

static uint32_t progress_char_add(ble_nus_t *p_nus, const ble_nus_init_t *p_nus_init)
{
	uint32_t err_code;
	ble_gatts_char_md_t char_md;
	ble_gatts_attr_md_t cccd_md;
	ble_gatts_attr_md_t attr_md;
	ble_gatts_attr_t attr_char_value;
	ble_uuid_t ble_uuid;

	// Initiliaze the structures
	memset(&cccd_md, 0, sizeof(cccd_md));
	memset(&char_md, 0, sizeof(char_md));
	memset(&attr_md, 0, sizeof(attr_md));
	memset(&attr_char_value, 0, sizeof(attr_char_value));

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);

	// Client Characteristic Configuration Descriptor metadata.
	cccd_md.vloc = BLE_GATTS_VLOC_STACK; // decide where to store the descriptor (the value of the CCCD), and once again we store it in the SoftDevice controlled part of memory (as we did with the characteristic)
	char_md.char_props.read = 1;	     // Enable read
	char_md.char_props.notify = 1;	     // Enable notifications
	char_md.p_char_user_desc = NULL;
	char_md.p_char_pf = NULL;
	char_md.p_user_desc_md = NULL;
	char_md.p_cccd_md = &cccd_md;

	char_md.p_sccd_md = NULL;

	ble_uuid.type = p_nus->uuid_type;
	ble_uuid.uuid = PROGRESS_VALUE_CHAR_UUID;

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm);

	attr_md.read_perm = p_nus_init->progress_char_attr_md.read_perm;
	attr_md.write_perm = p_nus_init->progress_char_attr_md.write_perm;
	attr_md.vloc = BLE_GATTS_VLOC_STACK; // BLE_GATTS_VLOC_STACK is the memory location (stack memory) to store the attributes (characteristic)
	attr_md.rd_auth = 0;
	attr_md.wr_auth = 0;
	attr_md.vlen = 0;

	attr_char_value.p_uuid = &ble_uuid;
	attr_char_value.p_attr_md = &attr_md;
	attr_char_value.init_len = sizeof(uint8_t); // sizeof(uint8_t);
	attr_char_value.init_offs = 0;
	attr_char_value.max_len = sizeof(uint8_t); // sizeof(uint8_t);

	err_code = sd_ble_gatts_characteristic_add(p_nus->service_handle, &char_md, &attr_char_value, &p_nus->progress_handles);
	if (err_code != NRF_SUCCESS) {
		return err_code;
	}

	return NRF_SUCCESS;
}

// Add the Results Characteristic.

static uint32_t results_char_add(ble_nus_t *p_nus, const ble_nus_init_t *p_nus_init)
{
	uint32_t err_code;
	ble_gatts_char_md_t char_md;
	ble_gatts_attr_md_t cccd_md;
	ble_gatts_attr_md_t attr_md;
	ble_gatts_attr_t attr_char_value;
	ble_uuid_t ble_uuid;

	// Initiliaze the structures
	memset(&cccd_md, 0, sizeof(cccd_md));
	memset(&char_md, 0, sizeof(char_md));
	memset(&attr_md, 0, sizeof(attr_md));
	memset(&attr_char_value, 0, sizeof(attr_char_value));

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);

	// Client Characteristic Configuration Descriptor metadata.
	cccd_md.vloc = BLE_GATTS_VLOC_STACK; // decide where to store the descriptor (the value of the CCCD), and once again we store it in the SoftDevice controlled part of memory (as we did with the characteristic)
	char_md.char_props.read = 1;	     // Enable read
	char_md.char_props.notify = 1;	     // Enable notifications
	char_md.p_char_user_desc = NULL;
	char_md.p_char_pf = NULL;
	char_md.p_user_desc_md = NULL;
	char_md.p_cccd_md = &cccd_md;

	char_md.p_sccd_md = NULL;

	ble_uuid.type = p_nus->uuid_type;
	ble_uuid.uuid = RESULTS_VALUE_CHAR_UUID;

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm);

	attr_md.read_perm = p_nus_init->results_char_attr_md.read_perm;
	attr_md.write_perm = p_nus_init->results_char_attr_md.write_perm;
	attr_md.vloc = BLE_GATTS_VLOC_STACK; // BLE_GATTS_VLOC_STACK is the memory location (stack memory) to store the attributes (characteristic)
	attr_md.rd_auth = 0;
	attr_md.wr_auth = 0;
	attr_md.vlen = 0;

	attr_char_value.p_uuid = &ble_uuid;
	attr_char_value.p_attr_md = &attr_md;
	attr_char_value.init_len = 8; // sizeof(uint8_t);
	attr_char_value.init_offs = 0;
	attr_char_value.max_len = 8; // sizeof(uint8_t);

	err_code = sd_ble_gatts_characteristic_add(p_nus->service_handle, &char_md, &attr_char_value, &p_nus->results_handles);
	if (err_code != NRF_SUCCESS) {
		return err_code;
	}

	return NRF_SUCCESS;
}

// This is where we will implement the notification
uint32_t ble_progress_update(ble_nus_t *p_nus, uint8_t custom_value)
{
	NRF_LOG_INFO("In ble_cus_custom_value_update. \r\n");
	if (p_nus == NULL) {
		return NRF_ERROR_NULL;
	}

	uint32_t err_code = NRF_SUCCESS;
	ble_gatts_value_t gatts_value;
	ble_nus_evt_t evt;

	// Initialize value struct.
	memset(&gatts_value, 0, sizeof(gatts_value));

	gatts_value.len = sizeof(custom_value);
	gatts_value.offset = 0;
	gatts_value.p_value = &custom_value;

	// Update database.
	err_code = sd_ble_gatts_value_set(p_nus->conn_handle,
	    p_nus->progress_handles.value_handle,
	    &gatts_value);
	if (err_code != NRF_SUCCESS) {
		return err_code;
	}

	// Send value if connected and notifying.
	if ((p_nus->conn_handle != BLE_CONN_HANDLE_INVALID)) {
		ble_gatts_hvx_params_t hvx_params;

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

		hvx_params.handle = p_nus->progress_handles.value_handle;
		hvx_params.type = BLE_GATT_HVX_NOTIFICATION;
		hvx_params.offset = gatts_value.offset;
		hvx_params.p_len = &gatts_value.len;
		hvx_params.p_data = gatts_value.p_value;

		err_code = sd_ble_gatts_hvx(p_nus->conn_handle, &hvx_params);
		// NRF_LOG_INFO("sd_ble_gatts_hvx result: %x. \r\n", err_code);
	} else {
		err_code = NRF_ERROR_INVALID_STATE;
		NRF_LOG_INFO("sd_ble_gatts_hvx result: NRF_ERROR_INVALID_STATE. \r\n");
	}
	evt.type = UART_RX_DATA;
	NRF_LOG_INFO("Event type: %d", evt.type);
	p_nus->data_handler(&evt);

	return err_code;
}

uint32_t ble_results_update(ble_nus_t *p_nus, uint8_t *results_value)
{
	NRF_LOG_INFO("In ble_cus_results_value_update. \r\n");
	if (p_nus == NULL) {
		return NRF_ERROR_NULL;
	}

	uint32_t err_code = NRF_SUCCESS;
	ble_gatts_value_t gatts_value;

	// Initialize value struct.
	memset(&gatts_value, 0, sizeof(gatts_value));

	gatts_value.len = sizeof(results_value);
	gatts_value.offset = 0;
	gatts_value.p_value = results_value;

	// Update database.
	err_code = sd_ble_gatts_value_set(p_nus->conn_handle,
	    p_nus->results_handles.value_handle,
	    &gatts_value);
	if (err_code != NRF_SUCCESS) {
		return err_code;
	}

	// Send value if connected and notifying.
	if ((p_nus->conn_handle != BLE_CONN_HANDLE_INVALID)) {
		ble_gatts_hvx_params_t hvx_params;

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

		hvx_params.handle = p_nus->results_handles.value_handle;
		hvx_params.type = BLE_GATT_HVX_NOTIFICATION;
		hvx_params.offset = gatts_value.offset;
		hvx_params.p_len = &gatts_value.len;
		hvx_params.p_data = gatts_value.p_value;

		err_code = sd_ble_gatts_hvx(p_nus->conn_handle, &hvx_params);
		NRF_LOG_INFO("sd_ble_gatts_hvx result: %x. \r\n", err_code);
	} else {
		err_code = NRF_ERROR_INVALID_STATE;
		NRF_LOG_INFO("sd_ble_gatts_hvx result: NRF_ERROR_INVALID_STATE. \r\n");
	}

	return err_code;
}

uint32_t ble_nus_init(ble_nus_t *p_nus, ble_nus_init_t const *p_nus_init)
{
	ret_code_t err_code;
	ble_uuid_t ble_uuid;
	ble_uuid128_t nus_base_uuid = NUS_BASE_UUID;
	ble_add_char_params_t add_char_params;

	VERIFY_PARAM_NOT_NULL(p_nus);
	VERIFY_PARAM_NOT_NULL(p_nus_init);

	// Initialize the service structure.
	p_nus->data_handler = p_nus_init->data_handler;

	/**@snippet [Adding proprietary Service to the SoftDevice] */
	// Add a custom base UUID.
	err_code = sd_ble_uuid_vs_add(&nus_base_uuid, &p_nus->uuid_type);
	VERIFY_SUCCESS(err_code);

	ble_uuid.type = p_nus->uuid_type;
	ble_uuid.uuid = BLE_UUID_NUS_SERVICE;

	// Add the service.
	err_code = sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY,
	    &ble_uuid,
	    &p_nus->service_handle);
	/**@snippet [Adding proprietary Service to the SoftDevice] */
	VERIFY_SUCCESS(err_code);

	err_code = rx_char_add(p_nus, p_nus_init);
	if (err_code != NRF_SUCCESS) {
		return err_code;
	}

	err_code = tx_char_add(p_nus, p_nus_init);
	if (err_code != NRF_SUCCESS) {
		return err_code;
	}

	err_code = progress_char_add(p_nus, p_nus_init);
	if (err_code != NRF_SUCCESS) {
		return err_code;
	}

	err_code = results_char_add(p_nus, p_nus_init);
	if (err_code != NRF_SUCCESS) {
		return err_code;
	}
}

uint32_t ble_nus_data_send(ble_nus_t *p_nus,
    uint8_t *p_data,
    uint16_t *p_length,
    uint16_t conn_handle)
{
	ret_code_t err_code;
	ble_gatts_hvx_params_t hvx_params;
	ble_nus_client_context_t *p_client;

	VERIFY_PARAM_NOT_NULL(p_nus);

	err_code = blcm_link_ctx_get(p_nus->p_link_ctx_storage, conn_handle, (void *)&p_client);
	VERIFY_SUCCESS(err_code);

	if ((conn_handle == BLE_CONN_HANDLE_INVALID) || (p_client == NULL)) {
		return NRF_ERROR_NOT_FOUND;
	}

	if (!p_client->is_notification_enabled) {
		return NRF_ERROR_INVALID_STATE;
	}

	if (*p_length > BLE_NUS_MAX_DATA_LEN) {
		return NRF_ERROR_INVALID_PARAM;
	}

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

	hvx_params.handle = p_nus->tx_handles.value_handle;
	hvx_params.p_data = p_data;
	hvx_params.p_len = p_length;
	hvx_params.type = BLE_GATT_HVX_NOTIFICATION;

	return sd_ble_gatts_hvx(conn_handle, &hvx_params);
}

#endif // NRF_MODULE_ENABLED(BLE_NUS)

[kleanthise]

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

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

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

#include "nrf_delay.h"
#include "nrf_drv_clock.h"
#include "nrf_drv_power.h"
#include "nrf_drv_usbd.h"
#include "nrf_gpio.h"

#include "app_error.h"
#include "app_usbd.h"
#include "app_usbd_cdc_acm.h"
#include "app_usbd_core.h"
#include "app_usbd_serial_num.h"
#include "app_usbd_string_desc.h"
#include "app_util.h"

#include "config.h"

#define LED_BLE_NUS_CONN (BSP_BOARD_LED_0)
#define LED_BLE_NUS_RX (BSP_BOARD_LED_1)
#define LED_CDC_ACM_CONN (BSP_BOARD_LED_2)
#define LED_CDC_ACM_RX (BSP_BOARD_LED_3)

#define LED_BLINK_INTERVAL 800

APP_TIMER_DEF(m_blink_ble);
APP_TIMER_DEF(m_blink_cdc);
APP_TIMER_DEF(m_notification_timer_id);

//---------------------------------------------------------------------------------------------------------------------------

#define COMMAND_ACTIVATION 0x01
#define COMMAND_TERMINATION 0x02
bool m_device_state = true;
static int counter = 0;
int number_of_steps = 5;

/**
 * @brief App timer handler for blinking the LEDs.
 *
 * @param p_context LED to blink.
 */
void blink_handler(void *p_context)
{
	bsp_board_led_invert((uint32_t)p_context);
}

#define ENDLINE_STRING "\r\n"

/**
 * @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 analyze
 *          how your product is supposed to react in case of an 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);
}

static void app_timer_handler(void *p_context)
{

	UNUSED_PARAMETER(p_context);
	ret_code_t err_code;
	// uint16_t ResData[7] = {0,1,0,0,0,1,1};
	static int8_t results_value[] = {1, 1, 0, 1, 1, 1, 1}; //{ResData[0], ResData[1], ResData[2], ResData[3], ResData[4], ResData[5], ResData[6]};
	counter++;

	NRF_LOG_INFO("Step event %d", counter);

	err_code = ble_progress_update(&m_nus, counter);
	APP_ERROR_CHECK(err_code);

	if (counter == number_of_steps) {

		err_code = ble_results_update(&m_nus, results_value);
		APP_ERROR_CHECK(err_code);
		NRF_LOG_INFO("Samples analysis is finished");
		NRF_LOG_INFO("Results");
		NRF_LOG_INFO("-------");
		NRF_LOG_INFO("E.Coli 0157 %d", false);
		NRF_LOG_INFO("Salmonella %d", false);
		NRF_LOG_INFO("Imidacloprid %d", true);
		NRF_LOG_INFO("Acrylamide %d", false);
		NRF_LOG_INFO("Ochratoxin A %d", false);
		NRF_LOG_INFO("Deoxynivalenol %d", false);
		NRF_LOG_INFO("Aflatoxin B2 %d", true);

		app_timer_stop(m_notification_timer_id);
		m_device_state = false;
	}
}

/** @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);
	err_code = app_timer_create(&m_blink_ble, APP_TIMER_MODE_REPEATED, blink_handler);
	APP_ERROR_CHECK(err_code);
	err_code = app_timer_create(&m_blink_cdc, APP_TIMER_MODE_REPEATED, blink_handler);
	APP_ERROR_CHECK(err_code);
	err_code = app_timer_create(&m_notification_timer_id, APP_TIMER_MODE_REPEATED, app_timer_handler);
	APP_ERROR_CHECK(err_code);
}

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

static void on_cus_evt(ble_nus_t *p_nus_service,
    ble_nus_evt_t *p_evt)
{
	ret_code_t err_code;

	switch (p_evt->type) {
	case BLE_CUS_EVT_NOTIFICATION_ENABLED:

		err_code = app_timer_start(m_notification_timer_id, COUNTER_INTERVAL, NULL);
		APP_ERROR_CHECK(err_code);
		break;

	case BLE_CUS_EVT_NOTIFICATION_DISABLED:

		err_code = app_timer_stop(m_notification_timer_id);
		APP_ERROR_CHECK(err_code);
		break;

	case BLE_CUS_EVT_CONNECTED:
		break;

	case BLE_CUS_EVT_DISCONNECTED:
		break;

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

/**
 * @brief Function for handling the data from the Nordic UART Service.
 *
 * @details This function processes the data received from the Nordic UART BLE Service and sends
 *          it to the USBD CDC ACM module.
 *
 * @param[in] p_evt Nordic UART Service event.
 */

static void nus_data_handler(ble_nus_evt_t *p_evt)
{
	ret_code_t err_code;
	if (p_evt->type == BLE_NUS_EVT_RX_DATA) {

		// bsp_board_led_invert(LED_BLE_NUS_RX);
		NRF_LOG_DEBUG("Received data from BLE NUS. Writing data on CDC ACM.");
		NRF_LOG_HEXDUMP_DEBUG(p_evt->params.rx_data.p_data, p_evt->params.rx_data.length);
		memcpy(m_nus_data_array, p_evt->params.rx_data.p_data, p_evt->params.rx_data.length);

		//// Add endline characters
		uint16_t length = p_evt->params.rx_data.length;
		if (length + sizeof(ENDLINE_STRING) < BLE_NUS_MAX_DATA_LEN) {
			memcpy(m_nus_data_array + length, ENDLINE_STRING, sizeof(ENDLINE_STRING));
			length += sizeof(ENDLINE_STRING);
		}

		if (p_evt->params.rx_data.p_data[0] == COMMAND_ACTIVATION) {
			if (m_device_state) {
				NRF_LOG_INFO("Device is activated.");
				err_code = app_timer_start(m_notification_timer_id, COUNTER_INTERVAL, NULL);
				APP_ERROR_CHECK(err_code);
				while (app_uart_put(COMMAND_ACTIVATION) != NRF_SUCCESS)
					;
			}
		} else {
			if (p_evt->params.rx_data.p_data[0] == COMMAND_TERMINATION) {
				m_device_state = false;
			}
			if (m_device_state == false) {
				NRF_LOG_INFO("Device is not activated.");
				while (app_uart_put(COMMAND_TERMINATION) != NRF_SUCCESS)
					;
				err_code = app_timer_stop(m_notification_timer_id);
				APP_ERROR_CHECK(err_code);
			}
		}

		// Send data through CDC ACM
		ret_code_t ret = app_usbd_cdc_acm_write(&m_app_cdc_acm,
		    m_nus_data_array,
		    length);

		if (ret != NRF_SUCCESS) {
			NRF_LOG_INFO("CDC ACM unavailable, data received: %s", m_nus_data_array);
		}
	}

	if (p_evt->type == UART_RX_DATA) {
		ret_code_t ret;
		uint16_t length = p_evt->params.tx_data.length;
		if (length + sizeof(ENDLINE_STRING) < BLE_NUS_MAX_DATA_LEN) {
			// memcpy(m_nus_data_array + length, ENDLINE_STRING, sizeof(ENDLINE_STRING));
			length += sizeof(ENDLINE_STRING);
		}
		NRF_LOG_INFO("UART_TX");
                nrf_delay_ms(100);
		ret = app_usbd_cdc_acm_write(&m_app_cdc_acm, m_nus_data_array, length);
		if (ret != NRF_SUCCESS) {
			NRF_LOG_INFO("CDC ACM unavailable, data received: %s", counter);
		}
	}
}

/** @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;

	ble_nus_init_t nus_init = {0};
	// memset(&nus_init, 0, sizeof(nus_init));
	/* Initialize Queued Write Module.*/

	nus_init.data_handler = nus_data_handler;

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.results_char_attr_md.cccd_write_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.results_char_attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.results_char_attr_md.write_perm);

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.progress_char_attr_md.cccd_write_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.progress_char_attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.progress_char_attr_md.write_perm);

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.rx_char_attr_md.cccd_write_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.rx_char_attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.rx_char_attr_md.write_perm);

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.tx_char_attr_md.cccd_write_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.tx_char_attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&nus_init.tx_char_attr_md.write_perm);

	err_code = ble_nus_init(&m_nus, &nus_init);
	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 = true;
	cp_init.evt_handler = NULL;
	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 does 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 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);
}

/**
 * @brief Function for handling advertising events.
 *
 * @details This function is 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 = app_timer_start(m_blink_ble,
		    APP_TIMER_TICKS(LED_BLINK_INTERVAL),
		    (void *)LED_BLE_NUS_CONN);
		APP_ERROR_CHECK(err_code);
		break;
	case BLE_ADV_EVT_IDLE:
		NRF_LOG_INFO("Advertising timeout, restarting.")
		advertising_start();
		break;
	default:
		break;
	}
}

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

	switch (p_ble_evt->header.evt_id) {
	case BLE_GAP_EVT_CONNECTED:
		NRF_LOG_INFO("BLE NUS connected");
		err_code = app_timer_stop(m_blink_ble);
		APP_ERROR_CHECK(err_code);
		bsp_board_led_on(LED_BLE_NUS_CONN);
		m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
		break;

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

	case BLE_GAP_EVT_PHY_UPDATE_REQUEST: {
		NRF_LOG_DEBUG("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.
		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_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST: {
		ble_gap_data_length_params_t dl_params;

		// Clearing the struct will effectively set members to @ref BLE_GAP_DATA_LENGTH_AUTO.
		memset(&dl_params, 0, sizeof(ble_gap_data_length_params_t));
		err_code = sd_ble_gap_data_length_update(p_ble_evt->evt.gap_evt.conn_handle, &dl_params, NULL);
		APP_ERROR_CHECK(err_code);
	} break;

	case BLE_GATTS_EVT_SYS_ATTR_MISSING:
		// 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.
		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.
		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;

	case BLE_EVT_USER_MEM_REQUEST:
		err_code = sd_ble_user_mem_reply(p_ble_evt->evt.gattc_evt.conn_handle, NULL);
		APP_ERROR_CHECK(err_code);
		break;

	case BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST: {
		ble_gatts_evt_rw_authorize_request_t req;
		ble_gatts_rw_authorize_reply_params_t auth_reply;

		req = p_ble_evt->evt.gatts_evt.params.authorize_request;

		if (req.type != BLE_GATTS_AUTHORIZE_TYPE_INVALID) {
			if ((req.request.write.op == BLE_GATTS_OP_PREP_WRITE_REQ) ||
			    (req.request.write.op == BLE_GATTS_OP_EXEC_WRITE_REQ_NOW) ||
			    (req.request.write.op == BLE_GATTS_OP_EXEC_WRITE_REQ_CANCEL)) {
				if (req.type == BLE_GATTS_AUTHORIZE_TYPE_WRITE) {
					auth_reply.type = BLE_GATTS_AUTHORIZE_TYPE_WRITE;
				} else {
					auth_reply.type = BLE_GATTS_AUTHORIZE_TYPE_READ;
				}
				auth_reply.params.write.gatt_status = APP_FEATURE_NOT_SUPPORTED;
				err_code = sd_ble_gatts_rw_authorize_reply(p_ble_evt->evt.gatts_evt.conn_handle,
				    &auth_reply);
				APP_ERROR_CHECK(err_code);
			}
		}
	} break; // BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST

	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, 64);
	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 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. */
static void buttons_leds_init(void)
{
	uint32_t err_code = bsp_init(BSP_INIT_LEDS, bsp_event_handler);
	APP_ERROR_CHECK(err_code);
}

/** @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 placing the application in low power state while waiting for events. */
static void power_manage(void)
{
	uint32_t err_code = sd_app_evt_wait();
	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)
{
	UNUSED_RETURN_VALUE(NRF_LOG_PROCESS());
	power_manage();
}

// USB CODE START
static bool m_usb_connected = false;

/** @brief User event handler @ref app_usbd_cdc_acm_user_ev_handler_t */
static void cdc_acm_user_ev_handler(app_usbd_class_inst_t const *p_inst,
    app_usbd_cdc_acm_user_event_t event)
{
	app_usbd_cdc_acm_t const *p_cdc_acm = app_usbd_cdc_acm_class_get(p_inst);

	switch (event) {
	case APP_USBD_CDC_ACM_USER_EVT_PORT_OPEN: {
		/*Set up the first transfer*/
		ret_code_t ret = app_usbd_cdc_acm_read(&m_app_cdc_acm,
		    m_cdc_data_array,
		    1);
		UNUSED_VARIABLE(ret);
		ret = app_timer_stop(m_blink_cdc);
		APP_ERROR_CHECK(ret);
		bsp_board_led_on(LED_CDC_ACM_CONN);
		NRF_LOG_INFO("CDC ACM port opened");
		break;
	}

	case APP_USBD_CDC_ACM_USER_EVT_PORT_CLOSE:
		NRF_LOG_INFO("CDC ACM port closed");
		if (m_usb_connected) {
			ret_code_t ret = app_timer_start(m_blink_cdc,
			    APP_TIMER_TICKS(LED_BLINK_INTERVAL),
			    (void *)LED_CDC_ACM_CONN);
			APP_ERROR_CHECK(ret);
		}
		break;

	case APP_USBD_CDC_ACM_USER_EVT_TX_DONE:
		break;

	case APP_USBD_CDC_ACM_USER_EVT_RX_DONE: {
		ret_code_t ret;
		static uint8_t index = 0;
		index++;

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

					do {
						uint16_t length = (uint16_t)index;
						if (length + sizeof(ENDLINE_STRING) < BLE_NUS_MAX_DATA_LEN) {
							memcpy(m_cdc_data_array + length, ENDLINE_STRING, sizeof(ENDLINE_STRING));
							length += sizeof(ENDLINE_STRING);
						}

						ret = ble_nus_data_send(&m_nus,
						    (uint8_t *)m_cdc_data_array,
						    &length,
						    m_conn_handle);

						if (ret == NRF_ERROR_NOT_FOUND) {
							NRF_LOG_INFO("BLE NUS unavailable, data received: %s", m_cdc_data_array);
							break;
						}

						if (ret == NRF_ERROR_RESOURCES) {
							NRF_LOG_ERROR("BLE NUS Too many notifications queued.");
							break;
						}

						if ((ret != NRF_ERROR_INVALID_STATE) && (ret != NRF_ERROR_BUSY)) {
							APP_ERROR_CHECK(ret);
						}
					} while (ret == NRF_ERROR_BUSY);
				}

				index = 0;
			}

			/*Get amount of data transferred*/
			size_t size = app_usbd_cdc_acm_rx_size(p_cdc_acm);
			NRF_LOG_DEBUG("RX: size: %lu char: %c", size, m_cdc_data_array[index - 1]);

			/* Fetch data until internal buffer is empty */
			ret = app_usbd_cdc_acm_read(&m_app_cdc_acm,
			    &m_cdc_data_array[index],
			    1);
			if (ret == NRF_SUCCESS) {
				index++;
			}
		} while (ret == NRF_SUCCESS);

		NRF_LOG_HEXDUMP_INFO(m_cdc_data_array, index);
		break;
	}
	default:
		break;
	}
}

static void usbd_user_ev_handler(app_usbd_event_type_t event)
{
	switch (event) {
	case APP_USBD_EVT_DRV_SUSPEND:
		break;

	case APP_USBD_EVT_DRV_RESUME:
		break;

	case APP_USBD_EVT_STARTED:
		break;

	case APP_USBD_EVT_STOPPED:
		app_usbd_disable();
		break;

	case APP_USBD_EVT_POWER_DETECTED:
		NRF_LOG_INFO("USB power detected");

		if (!nrf_drv_usbd_is_enabled()) {
			app_usbd_enable();
		}
		break;

	case APP_USBD_EVT_POWER_REMOVED: {
		NRF_LOG_INFO("USB power removed");
		ret_code_t err_code = app_timer_stop(m_blink_cdc);
		APP_ERROR_CHECK(err_code);
		bsp_board_led_off(LED_CDC_ACM_CONN);
		m_usb_connected = false;
		app_usbd_stop();
	} break;

	case APP_USBD_EVT_POWER_READY: {
		NRF_LOG_INFO("USB ready");
		ret_code_t err_code = app_timer_start(m_blink_cdc,
		    APP_TIMER_TICKS(LED_BLINK_INTERVAL),
		    (void *)LED_CDC_ACM_CONN);
		APP_ERROR_CHECK(err_code);
		m_usb_connected = true;
		app_usbd_start();
	} break;

	default:
		break;
	}
}

// USB CODE END

/** @brief Application main function. */
int main(void)
{
	ret_code_t ret;
	static const app_usbd_config_t usbd_config = {
	    .ev_state_proc = usbd_user_ev_handler};
	// Initialize.
	log_init();
	timers_init();

	buttons_leds_init();

	app_usbd_serial_num_generate();

	ret = nrf_drv_clock_init();
	APP_ERROR_CHECK(ret);

	NRF_LOG_INFO("USBD BLE UART example started.");

	ret = app_usbd_init(&usbd_config);
	APP_ERROR_CHECK(ret);

	app_usbd_class_inst_t const *class_cdc_acm = app_usbd_cdc_acm_class_inst_get(&m_app_cdc_acm);
	ret = app_usbd_class_append(class_cdc_acm);
	APP_ERROR_CHECK(ret);

	ble_stack_init();
	gap_params_init();
	gatt_init();
	services_init();
	advertising_init();
	conn_params_init();

	// Start execution.
	advertising_start();

	ret = app_usbd_power_events_enable();
	APP_ERROR_CHECK(ret);

	// Enter main loop.
	for (;;) {
		while (app_usbd_event_queue_process()) {

			
			/* Nothing to do */
		}

		idle_state_handle();
	}
}

/**
 * @}
 */

main code is attached as well

[kleanthise]

If it helps the issue is happening in the function nus_data_handler . I have a counter that is updating a characteristic value and i would like to send that value to the terminal via usb. When i am looking at the debug screen of segger everything seems to be working fine. However on the terminal screen the data send are wrong 

[Einar Thorsrud]

Where should this be printed? What you do here (except for the issues described in my previous post) is to take the integer value in the counter variable and convert it to a string in the buf char array. So now it resides as a C string in buf. But it is not printed by itself unless you do so.

[kleanthise]

This should be transferred over to the usb and printed on my computer terminal. I thought that this command : ret = app_usbd_cdc_acm_write(&m_app_cdc_acm, buf, j); would transfer the data over to my usb port and be printed on the terminal but this is not the case.

Is it correct the way i understood it ? or shall i use a different command to print the data to my terminal connection ?

[Einar Thorsrud]

Hi,

The app_usbd_cdc_acm_write() will write to USB CDC ACM, yes. So you should see it on your computer (provided things are done correctly and you have a terminal on your computer connected to that virtual UART port). You can see a simple example of the same in examples/peripheral/usbd_cdc_acm/main.c:

            static int  frame_counter;

            size_t size = sprintf(m_tx_buffer, "Hello USB CDC FA demo: %u\r\n", frame_counter);

            ret = app_usbd_cdc_acm_write(&m_app_cdc_acm, m_tx_buffer, size);
            if (ret == NRF_SUCCESS)
            {
                ++frame_counter;
            }

kleanthise said:

my terminal connection

If this is terminal via USB CDC ACM, then the above is the way to do it. If it is via UART or NUS, then other approaches are needed (see relevant samples for that). You have most of the code in your project though, the main thing should be to fix up the generic C programming mistakes we have discussed before in this thread.

[kleanthise]

Thanks a lot i have modified the code and now the counter is printed over to terminal. However the string is presented as an ascii. Is there a way to convert it to hex ? 

I have for example one condition in hex that is the command activation (0x01) when the user sends that command via BLE the code is activated and it runs a sequence. However when i switch my terminal to ascii i can only monitor the commands received from the counter and not the starting command. Is there a way to print the hex command while looking at ascii characters ? 

[Einar Thorsrud]

Convert the hex data to ascii(for instance using snprintf) so that everything you send to the terminal is ascii