How to take ESP32 BLE Notify

[HuyYuh]

Hello, I'm trying to take data whenever BLE Server noyify, here is my callback function

Code: Select all

static void notifyCallback(BLERemoteCharacteristic* pBLERemoteCharacteristic,
                            uint8_t* pData, size_t length, 
                            bool isNotify)
{
  Serial.print("Length: ");
  Serial.println(length);
  Serial.print("pData :");
  Serial.println((char *)pData);
  char temp[length];
  for (int i=0; i<length; i++) {
    temp[i] = (char)pData[i];
  }
  Serial.print("temp: ");
  Serial.println(temp);
}

However, I cannot take notify data:

Length: 3
pData :chi⸮⸮?
temp: chi⸮⸮⸮?⸮⸮⸮?8⸮⸮?⸮Z
⸮⸮⸮⸮?
Length: 3
pData :hay⸮⸮?
temp: hay⸮⸮⸮?⸮⸮⸮?8⸮⸮?⸮Z
⸮⸮⸮⸮?
Length: 9
pData :heyGoogle
temp: heyGoogle⸮⸮?8⸮⸮?⸮Z
⸮⸮⸮⸮?
Length: 2
pData :hiyGoogle
temp: hi
⸮⸮⸮?⸮⸮⸮?8⸮⸮?⸮Z
⸮⸮⸮⸮?
Length: 5
pData :motayogle
temp: motay⸮⸮?⸮⸮⸮?8⸮⸮?⸮Z
⸮⸮⸮⸮?
Length: 6

I don't know how to do it. Please help me.
Thanks in advance

[chegewara]

From what i can see it is working good. The problem is in your code.

You need to create array with size length + 1, to have null terminated string.