[Urgent][Stuck Problem] BLE setValue in callback function! #592

void dataSyncCharCharacteristicWritten(BLEDevice central, BLECharacteristic characteristic) {
// 1. read external serial flash 
//  code here
// 2. save data in buffer from serial flash memory  
// code here 
// 3. nofity and send to application buff Value 
for (int i = 0; i < register_index; i++) {
    syncChar.setValue(syncBuff[i], SAVE_UNIT_STEP);
}
}

BLECharacteristic syncChar("FFF2", BLERead | BLEWrite | BLENotify , 20);