changing the BLE device name, BLE service and GATT Characteristics dynamically

Question

Hi, I am using nRF52832 module (GAP peripheral, GATT server) with nRF5SDK, ble_app_uart_pca10040_s112 application. 
 I need some help on dynamically changing the BLE device name, BLE service and GATT Characteristics. 
 What I tried: In main(), I initialized only the UART module. Once UART is up, the nRF module receives data from an application chip (MCU). In uart_event_handle function, I use a function call to process the received data and set the BLE device name accordingly, inside this function call I am initializing BLE stack, GAP parameters, GATT Init, Services Init followed by BLE advertisement. 
 This way, I was successfully able to set BLE device name and Services dynamically. However, after few minutes of communication with a GATT client, incorrect/incomplete data is being transmitted to that peer device. 
 Is it good to initialize BLE this way? If not, what should be done? 
 Also, I have found few of the forum discussions on how to change the BLE Device name in run time, but not seen anything related to changing GATT characteristics dynamically. Please help, Thank you in advance.

dejans · Accepted Answer

Hi, Could you please replace your uart_event_handle() with the one provided below and try to reproduce your issue?

Fullscreen 
 1588.PKANNAN_uart_event_handle.c 
 Download 
 
 /**@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' '
' (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)
{
 // Keep static keep word
 static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
 uint8_t process_data_array[BLE_NUS_MAX_DATA_LEN];
 static uint8_t index = 0;
 uint32_t err_code;
 uint16_t length;

switch (p_event->evt_type)
 {
 case APP_UART_DATA_READY:
 UNUSED_VARIABLE(app_uart_get(&data_array[index]));
 index++;

if ((data_array[index - 1] == '
') ||
 (data_array[index - 1] == '') ||
 (index >= m_ble_nus_max_data_len))
 {
 if (index > 1)
 {
 if(data_array[0]=='#')
 {
 // Copy the array like this
 memcpy(&process_data_array, &data_array, index);
 err_code = process_mcu_data(&process_data_array[0]);
 }

else
 {
 do
 {
 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:
 APP_ERROR_HANDLER(p_event->data.error_communication);
 break;

case APP_UART_FIFO_ERROR:
 APP_ERROR_HANDLER(p_event->data.error_code);
 break;

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

Best regards, Dejan

changing the BLE device name, BLE service and GATT Characteristics dynamically

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