Issue with OTA Firmware Update (deprecated / off topic)

[FurqanChaudhary]

First of all, I would like to thank you immensely for the wonderful Firebase Arduino Client Library for ESP8266 and ESP32 (version 4.4.14). It has been instrumental in helping me develop many projects.

Currently, I'm encountering an issue related to OTA updates from Firebase Storage, and I need your assistance to resolve it urgently as this project is critical and needs to be completed as soon as possible

The specific error I receive is:

"Download firmware failed, not connected
not connected"

The code runs perfectly until I issue an "update" command from Firebase RTDB. When the command is received, the code enters the OTA update routine but then returns the error mentioned above, indicating "not connected." I'm unable to determine the cause of this error.

Could you please help me solve this problem? I've attached my code file for your reference.

#include <Arduino.h>
#if defined(ESP32)
#include <WiFi.h>
#elif defined(ESP8266)
#include <ESP8266WiFi.h>
#endif
#include <Firebase_ESP_Client.h>
#include <MCP23017.h>
#include <Wire.h>
#include <string.h>
// Provide the token generation process info.
#include "addons/TokenHelper.h"
// Provide the RTDB payload printing info and other helper functions.
#include "addons/RTDBHelper.h"
#include "EMONIC.h"

// Define Firebase Data object
FirebaseData fbdo;
FirebaseData stream;

FirebaseAuth auth;
FirebaseConfig config;

bool taskCompleted = false; // added for OTA update to make update to happen one time

unsigned long sendDataPrevMillis = 0;
uint8_t count = 0;
bool signupOK = false;

void status_reset();
void reset_floor();
void Operation_setup();
void configurePinsWithPinMode();
void ELEV_OPE_STA(const char *, const char *, const char *, const char *, const char *, const char *, const char *, const char *);

volatile bool dataChanged = false;

// Variable to save USER UID
String uid;
unsigned long int a = 0;

#define MCP23017_I2C_ADDRESS1 0x20 // I2C address of the MCP23017 IC ------INPUT IC MCP23017 -----U17
#define MCP23017_I2C_ADDRESS2 0x24 // I2C address of the MCP23017 IC ------OUTPUT IC MCP23017-----U18

unsigned long number = 0;

// const uint8_t PARKING = 8; // GPB0 (1) of the MCP23017----PARKING COMMAND FROM PCB
// const uint8_t FIREMAN = 9;
MCP23017 mcp23017 = MCP23017(MCP23017_I2C_ADDRESS1); //----------- U17
MCP23017 mcp23017_1 = MCP23017(MCP23017_I2C_ADDRESS2); //------------ U18

/////////
void streamCallback(MultiPathStream stream)
{
size_t numChild = sizeof(childPath) / sizeof(childPath[0]);

for (size_t i = 0; i < numChild; i++)
{
if (stream.get(childPath[i]))
{
// Serial.printf("path: %s, type: %s, value: %s\n", stream.dataPath.c_str(), stream.type.c_str(), stream.value.c_str());
// Serial.printf("path: %s\n",stream.dataPath.c_str());
// Serial.printf("type: %s\n",stream.type.c_str());
// Serial.printf("value: %s\n",stream.value.c_str());

  char charArray[stream.dataPath.length() + 1];
  char valueArray[stream.value.length() + 1];
  strcpy(valueArray, stream.value.c_str());
  strcpy(charArray, stream.dataPath.c_str());

  /*================= FOR OTA UPDATE ========================= */
  
  if (strcmp(FIRMWARE_VERSION_LEVEL_TAG.c_str() , charArray) == 0 && strcmp("UPDATE", valueArray) == 0)
  {
    OTA_UPDATE();
  }

  /*================= FOR OTA UPDATE ========================= */

  if (strcmp(FIRE_STREAM, charArray) == 0 && strcmp(ON_VALUE, valueArray) == 0)
  {
    mcp23017_1.digitalWrite(FIREMAN, HIGH);
    // Serial.printf("command for FIRE HIGH \n");
  }
  else
  {
    if (strcmp(FIRE_STREAM, charArray) == 0 && strcmp(OFF_VALUE, valueArray) == 0)
    {
      mcp23017_1.digitalWrite(FIREMAN, LOW);
      // Serial.printf("command for FIRE LOW \n");
    }
  }

  if (strcmp(PARKING_STREAM, charArray) == 0 && strcmp(ON_VALUE, valueArray) == 0)
  {
    mcp23017_1.digitalWrite(PARKING, HIGH);
    // Serial.printf("command for PARKING HIGH \n");
  }
  else
  {
    if (strcmp(PARKING_STREAM, charArray) == 0 && strcmp(OFF_VALUE, valueArray) == 0)
    {
      mcp23017_1.digitalWrite(PARKING, LOW);
      // Serial.printf("command for PARKING LOW \n");
    }
  }

  if (strcmp(FIRE_BYPASS_STREAM, charArray) == 0 && strcmp(ON_VALUE, valueArray) == 0)
  {
    mcp23017_1.digitalWrite(FIRE_BYPASS, HIGH);
    // Serial.printf("command for FIRE BYPASS  HIGH \n");
  }
  else
  {
    if (strcmp(FIRE_BYPASS_STREAM, charArray) == 0 && strcmp(OFF_VALUE, valueArray) == 0)
    {
      mcp23017_1.digitalWrite(FIRE_BYPASS, LOW);
      // Serial.printf("command for FIRE BYPASS LOW \n");
    }
  }
}

}

// Serial.println();

// This is the size of stream payload received (current and max value)
// Max payload size is the payload size under the stream path since the stream connected
// and read once and will not update until stream reconnection takes place.
// This max value will be zero as no payload received in case of ESP8266 which
// BearSSL reserved Rx buffer size is less than the actual stream payload.
Serial.printf("Received stream payload size: %d (Max. %d)\n\n", stream.payloadLength(), stream.maxPayloadLength());

// Due to limited of stack memory, do not perform any task that used large memory here especially starting connect to server.
// Just set this flag and check it status later.
dataChanged = true;
}

void streamTimeoutCallback(bool timeout)
{
if (timeout)
Serial.println("stream timed out, resuming...\n");

if (!stream.httpConnected())
Serial.printf("error code: %d, reason: %s\n\n", stream.httpCode(), stream.errorReason().c_str());
}

/////////

void setup()
{

Serial.begin(115200);
pinMode(LED_BUILTIN, OUTPUT);
WiFi.hostname(newHostname); // hostname added
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
Serial.print("Connecting to Wi-Fi");
while (WiFi.status() != WL_CONNECTED)
{

Serial.print(".");
digitalWrite(LED_BUILTIN, LOW);
delay(200);
digitalWrite(LED_BUILTIN, HIGH);
delay(200);

}
Serial.println();
Serial.print("Connected with IP: ");
Serial.println(WiFi.localIP());
Serial.println();

/* Assign the api key (required) */
config.api_key = API_KEY;
// Assign the user sign in credentials
auth.user.email = USER_EMAIL;
auth.user.password = USER_PASSWORD;

/* Assign the RTDB URL (required) */
config.database_url = DATABASE_URL;

/* Assign the callback function for the long running token generation task */
config.token_status_callback = tokenStatusCallback; // see addons/TokenHelper.h
// Assign the maximum retry of token generation
config.max_token_generation_retry = 5;

Firebase.reconnectNetwork(true);

//fbdo.setResponseSize(4096); // for trial made comment uncomment while testing if require

fbdo.setBSSLBufferSize(4096 /* Rx buffer size in bytes from 512 - 16384 /, 1024 / Tx buffer size in bytes from 512 - 16384 /);
config.fcs.download_buffer_size = 2048;
// Recommend for ESP8266 stream, adjust the buffer size to match your stream data size
#if defined(ESP8266)
stream.setBSSLBufferSize(2048 / Rx in bytes, 512 - 16384 /, 512 / Tx in bytes, 512 - 16384 */);
#endif
Firebase.begin(&config, &auth);

// Serial.begin(115200);
Serial.print("start");

Serial.println();
Serial.println("Start I2C scanner ...");
Serial.print("\r\n");
byte count = 0;

Wire.begin();
for (byte i = 8; i < 120; i++)
{
Wire.beginTransmission(i);
if (Wire.endTransmission() == 0)
{
Serial.print("Found I2C Device: ");
Serial.print(" (0x");
Serial.print(i, HEX);
Serial.println(")");
count++;
delay(1);
}
}
Serial.print("\r\n");
Serial.println("Finish I2C scanner");
Serial.print("Found ");
Serial.print(count, HEX);
Serial.println(" Device(s).");

// Firebase.begin(FIREBASE_HOST, FIREBASE_AUTH);
mcp23017.init(); // initialize MCP23017 IC
mcp23017_1.init(); // initialize MCP23017 IC

// Configure MCP23017 I/O pins
configurePinsWithPinMode(); // familiar pinMode() style

// Reset MCP23017 ports
mcp23017.writeRegister(MCP23017Register::GPIO_A, 0x00);
mcp23017.writeRegister(MCP23017Register::GPIO_B, 0x00);
mcp23017_1.writeRegister(MCP23017Register::GPIO_A, 0x00);
mcp23017_1.writeRegister(MCP23017Register::GPIO_B, 0x00);

// Getting the user UID might take a few seconds
Serial.println("Getting User UID");
while ((auth.token.uid) == "")
{
Serial.print('.');
delay(1000);
}
// Print user UID
uid = auth.token.uid.c_str();
Serial.print("User UID: ");
Serial.print(uid);
Operation_setup();

Firebase.RTDB.setString(&fbdo, FIRMWARE_UPDATE_COMMAND, "NO_UPDATE");
Firebase.RTDB.setString(&fbdo, FIRMWARE_STATUS, "NO-STATUS");// for downloading status

if (!Firebase.RTDB.beginMultiPathStream(&stream, parentPath))
Serial.printf("sream begin error, %s\n\n", stream.errorReason().c_str());

Firebase.RTDB.setMultiPathStreamCallback(&stream, streamCallback, streamTimeoutCallback);

}

/============================ OTA UPDATE CALL BACK FUNCTION ======================/
void fcsDownloadCallback(FCS_DownloadStatusInfo info)
{
// Firebase.RTDB.setString(&fbdo, FIRMWARE_STATUS, "STARTED"); // for downloading status

if (info.status == firebase_fcs_download_status_init)
{
    Serial.printf("Downloading firmware %s (%d)\n", info.remoteFileName.c_str(), info.fileSize);
}
else if (info.status == firebase_fcs_download_status_download)
{
    Serial.printf("Downloaded %d%s, Elapsed time %d ms\n", (int)info.progress, "%", info.elapsedTime);
   //Firebase.RTDB.setString(&fbdo, FIRMWARE_STATUS, (String)info.progress);// for downloading status
}
else if (info.status == firebase_fcs_download_status_complete)
{
   //Firebase.RTDB.setString(&fbdo, FIRMWARE_STATUS, "COMPLETED--RESTARTING");// for downloading status

    Serial.println("Update firmware completed.");
    Serial.println();
    Serial.println("Restarting...\n\n");
    delay(2000);
      #if defined(ESP32) || defined(ESP8266)
    ESP.restart();
      #elif defined(ARDUINO_RASPBERRY_PI_PICO_W)
    rp2040.restart();
    #endif
}
else if (info.status == firebase_fcs_download_status_error)
{
    Serial.printf("Download firmware failed, %s\n", info.errorMsg.c_str());
}

}
/============================ OTA UPDATE CALL BACK FUNCTION ======================/

void Operation_setup()
{
delay(100);
}

void configurePinsWithPinMode()
{
// Configure output pins
mcp23017.pinMode(S1, INPUT);
mcp23017.pinMode(S2, INPUT);
mcp23017.pinMode(S3, INPUT);
mcp23017.pinMode(S4, INPUT);
mcp23017.pinMode(S5, INPUT);
mcp23017.pinMode(S6, INPUT);
mcp23017.pinMode(UP, INPUT);
mcp23017.pinMode(DOWN, INPUT);

mcp23017.pinMode(FO, INPUT);
mcp23017.pinMode(DO, INPUT);
mcp23017.pinMode(FA, INPUT);
mcp23017.pinMode(NPWT, INPUT);
mcp23017.pinMode(ST1, INPUT);
mcp23017.pinMode(ST2, INPUT);
mcp23017.pinMode(ST3, INPUT);
mcp23017.pinMode(EPO, INPUT);

mcp23017_1.pinMode(EQT, INPUT);

mcp23017_1.pinMode(FaultAlarm, INPUT);
mcp23017_1.pinMode(FIREMAN, OUTPUT);
mcp23017_1.pinMode(PARKING, OUTPUT);
mcp23017_1.pinMode(FIRE_BYPASS, OUTPUT);
}
void FLOOR_DETAIL()
{
if ((mcp23017.digitalRead(S1) == 0) && (mcp23017.digitalRead(S2) == 0) && (mcp23017.digitalRead(S3) == 0) && (mcp23017.digitalRead(S4) == 0) && (mcp23017.digitalRead(S5) == 0) && (mcp23017.digitalRead(S6) == 0) && (floor_access[0] == 1))
{
Firebase.RTDB.setString(&fbdo, FLOOR_PATH, "-");

reset_floor();
floor_access[0] = 0;

}

if ((mcp23017.digitalRead(S1) == 1) && (mcp23017.digitalRead(S2) == 0) && (mcp23017.digitalRead(S3) == 0) && (mcp23017.digitalRead(S4) == 0) && (mcp23017.digitalRead(S5) == 0) && (mcp23017.digitalRead(S6) == 0) && (floor_access[1] == 1)) // STOP-1
{
Firebase.RTDB.setString(&fbdo, FLOOR_PATH, "1");
reset_floor();
floor_access[1] = 0;
}

if ((mcp23017.digitalRead(S1) == 0) && (mcp23017.digitalRead(S2) == 1) && (mcp23017.digitalRead(S3) == 0) && (mcp23017.digitalRead(S4) == 0) && (mcp23017.digitalRead(S5) == 0) && (mcp23017.digitalRead(S6) == 0) && (floor_access[2] == 1)) // STOP-2
{
Firebase.RTDB.setString(&fbdo, FLOOR_PATH, "2");
reset_floor();
floor_access[2] = 0;
}

}
void NORMAL_POWER_STANDBY()
{
if ((mcp23017.digitalRead(NPWT) == 0) && (np_sp_v == 0))
{
Firebase.RTDB.setString(&fbdo, POWER_PATH, POWER[0]);
np_sp_v = 1;
}

if ((mcp23017.digitalRead(NPWT) == 1) && (np_sp_v == 1))
{
Firebase.RTDB.setString(&fbdo, POWER_PATH, POWER[1]);

np_sp_v = 0;

}
}

void SEISMIC()
{

if ((mcp23017_1.digitalRead(EQT) == 0) && (seismic_v == 0))
{
Firebase.RTDB.setString(&fbdo, SEISMIC_PATH, OFF);
seismic_v = 1;
}
if ((mcp23017_1.digitalRead(EQT) == 1) && (seismic_v == 1))
{
Firebase.RTDB.setString(&fbdo, SEISMIC_PATH, ON);
seismic_v = 0;
}
}

void DIRECTION()
{
if ((mcp23017.digitalRead(UP) == 0) && (mcp23017.digitalRead(DOWN) == 0) && ((up_v == 0) || (down_v == 0)))
{
Firebase.RTDB.setString(&fbdo, DIRECTION_PATH, DIRECTION_COND[0]);
up_v = 1;
down_v = 1;
}

if ((mcp23017.digitalRead(UP) == 1) && (mcp23017.digitalRead(DOWN) == 0) && (up_v == 1))
{
Firebase.RTDB.setString(&fbdo, DIRECTION_PATH, DIRECTION_COND[1]);
up_v = 0;
down_v = 1;
}
if ((mcp23017.digitalRead(UP) == 0) && (mcp23017.digitalRead(DOWN) == 1) && (down_v == 1))
{
Firebase.RTDB.setString(&fbdo, DIRECTION_PATH, DIRECTION_COND[2]);
up_v = 1;
down_v = 0;
}
}

void FIREMAN_OPERATION()
{
if ((mcp23017.digitalRead(FO) == 0) && (fire_op_v == 0))
{
Firebase.RTDB.setString(&fbdo, FIREMAN_OP_PATH, OFF);
fire_op_v = 1;
}

if ((mcp23017.digitalRead(FO) == 1) && (fire_op_v == 1))
{
Firebase.RTDB.setString(&fbdo, FIREMAN_OP_PATH, ON);
fire_op_v = 0;
}
}

void DO_DC()
{

if ((mcp23017.digitalRead(DO) == 0) && (do_dc_v == 0))
{
Firebase.RTDB.setString(&fbdo, DOOR_PATH, CLOSE);
do_dc_v = 1;
}

if ((mcp23017.digitalRead(DO) == 1) && (do_dc_v == 1))
{
Firebase.RTDB.setString(&fbdo, DOOR_PATH, OPEN);
do_dc_v = 0;
}
}

void FIRE_ALARM_LAMP()
{
if ((mcp23017.digitalRead(FA) == 0) && (fire_lamp_v == 0))
{
Firebase.RTDB.setString(&fbdo, FIRE_ALRM_PATH, OFF);
fire_lamp_v = 1;
}

if ((mcp23017.digitalRead(FA) == 1) && (fire_lamp_v == 1))
{
Firebase.RTDB.setString(&fbdo, FIRE_ALRM_PATH, ON);
fire_lamp_v = 0;
}
}

void reset_floor()
{
for (i = 0; i <= 64; i++)
{
floor_access[i] = 1;
}
}

void Opertaion_Status()
{

if ((mcp23017.digitalRead(ST1) == 0) && (mcp23017.digitalRead(ST2) == 0) && (mcp23017.digitalRead(ST3) == 0) && (status_lift[0] == 1)) // NORMAL OR GROUP
{
ELEV_OPE_STA("1CAR", OFF, OFF, OFF, OFF, OFF, OFF, OFF);
status_reset();
status_lift[0] = 0;
}

if ((mcp23017.digitalRead(ST1) == 1) && (mcp23017.digitalRead(ST2) == 0) && (mcp23017.digitalRead(ST3) == 0) && (status_lift[1] == 1)) // ATTAINDENT
{
ELEV_OPE_STA("1CAR", ON, OFF, OFF, OFF, OFF, OFF, OFF);
status_reset();
status_lift[1] = 0;
}
if ((mcp23017.digitalRead(ST1) == 0) && (mcp23017.digitalRead(ST2) == 1) && (mcp23017.digitalRead(ST3) == 0) && (status_lift[2] == 1)) // VIP
{
ELEV_OPE_STA("1CAR", OFF, ON, OFF, OFF, OFF, OFF, OFF);

status_reset();
status_lift[2] = 0;

}

if ((mcp23017.digitalRead(ST1) == 1) && (mcp23017.digitalRead(ST2) == 1) && (mcp23017.digitalRead(ST3) == 0) && (status_lift[3] == 1)) // INDEPT.
{

ELEV_OPE_STA("1CAR", OFF, OFF, ON, OFF, OFF, OFF, OFF);
status_reset();
status_lift[3] = 0;

}

if ((mcp23017.digitalRead(ST1) == 0) && (mcp23017.digitalRead(ST2) == 0) && (mcp23017.digitalRead(ST3) == 1) && (status_lift[4] == 1)) // PARKING
{

ELEV_OPE_STA("1CAR", OFF, OFF, OFF, ON, OFF, OFF, OFF);
status_reset();
status_lift[4] = 0;

}

if ((mcp23017.digitalRead(ST1) == 1) && (mcp23017.digitalRead(ST2) == 0) && (mcp23017.digitalRead(ST3) == 1) && (status_lift[5] == 1)) // MAINTENANCE
{

ELEV_OPE_STA("1CAR", OFF, OFF, OFF, OFF, ON, OFF, OFF);
status_reset();
status_lift[5] = 0;

}

if ((mcp23017.digitalRead(ST1) == 0) && (mcp23017.digitalRead(ST2) == 1) && (mcp23017.digitalRead(ST3) == 1) && (status_lift[6] == 1)) // ALARM FAULT (#EO)
{

ELEV_OPE_STA("1CAR", OFF, OFF, OFF, OFF, OFF, ON, OFF);
status_reset();
status_lift[6] = 0;

}

if ((mcp23017.digitalRead(ST1) == 1) && (mcp23017.digitalRead(ST2) == 1) && (mcp23017.digitalRead(ST3) == 1) && (status_lift[7] == 1)) // ABNORMAL
{
// Firebase.RTDB.setString(&fbdo, ATT_PATH, ON);
ELEV_OPE_STA("1CAR", OFF, OFF, OFF, OFF, OFF, OFF, ON);
status_reset();
status_lift[7] = 0;
}
}

void status_reset()
{
for (j = 0; j <= 8; j++)
{
status_lift[j] = 1;
}
}

void Power_operation()
{

if ((mcp23017.digitalRead(EPO) == 0) && (emer_power_v == 0))
{
Firebase.RTDB.setString(&fbdo, EMER_PATH, OFF);
emer_power_v = 1;
}
if ((mcp23017.digitalRead(EPO) == 1) && (emer_power_v == 1))
{
Firebase.RTDB.setString(&fbdo, EMER_PATH, ON);
emer_power_v = 0;
}
}

void ELEV_OPE_STA(const char *ELEV, const char *ATT, const char *VIP, const char *INDT, const char *PARK, const char *MAINT, const char *FAULT_ALM, const char *ABNORM)
{
Firebase.RTDB.setString(&fbdo, ELEV_TYPE, ELEV);
Firebase.RTDB.setString(&fbdo, ATT_PATH, ATT);
Firebase.RTDB.setString(&fbdo, VIP_OP_PATH, VIP);
Firebase.RTDB.setString(&fbdo, INDT_PATH, INDT);
Firebase.RTDB.setString(&fbdo, PARK_PATH, PARK);
Firebase.RTDB.setString(&fbdo, MAINT_PATH, MAINT);
Firebase.RTDB.setString(&fbdo, FAULT_ALM_PATH, FAULT_ALM);
Firebase.RTDB.setString(&fbdo, ABNORM_PATH, ABNORM);
}

void loop()
{

// input_command_from_PC_GUI();

if (Firebase.isTokenExpired())
{
Firebase.refreshToken(&config);
Serial.println("Refresh token");
}
FLOOR_DETAIL();
NORMAL_POWER_STANDBY();
SEISMIC();
Opertaion_Status();
DIRECTION();
FIREMAN_OPERATION();
DO_DC();
FIRE_ALARM_LAMP();
Power_operation();
}
void OTA_UPDATE()
{
/================================= CHECKING ONCE FIRMWARE UPDATE -- START ==================/

if (Firebase.ready() && !taskCompleted)
{
//taskCompleted = true;

    // If you want to get download url to use with your own OTA update process using core update library,
    // see Metadata.ino example

    Serial.println("\nDownload firmware file...\n");

    // This function will allocate 16k+ memory for internal SSL client.
    if (!Firebase.Storage.downloadOTA(&fbdo, STORAGE_BUCKET_ID /* Firebase Storage bucket id */, REMOTE_FIRMWARE_LOCATION /* path of firmware file stored in the bucket */, fcsDownloadCallback /* callback function */))
        Serial.println(fbdo.errorReason());
}

/================================= CHECKING ONCE FIRMWARE UPDATE -- END ==================/
}

[mobizt]

You are posting in the wrong repo.

The library you mentioned is deprecated and not active in development and no more bugs fix.

For the error not connected, you have to check the network connection and the free Heap.

If you use WiFi Manager or reconnect the WiFi with your own code, you have to remove the function Firebase.reconnectWiFi or Firebase.reconnectNetwork from your code.

You have to check for free memory available which may be too low for the internal SSL client to work.

I can't tell the minimum memory that the SSL client and system tasks to work before they fail but you should try to minimize the memory usage in case of memory is concerned.

[mobizt]

You have to use different FirebaseData objects, one for Realtime database and another for Firebase storage because they connect to different servers and API endpoints.

You should not place the code that involved the WiFi and server connection in the callback function (stream callback) because it uses stack and you may run out of memory due to nest callback i.e. OTA should not run by code inside the stream callback.

You should store the stream status in the global variable. Then check this variable in the main loop and do some OTA there.

[FurqanChaudhary]

I used the different FirebaseData Objects, I tried this also "You should store the stream status in the global variable. Then check this variable in the main loop and do some OTA there". but still, i get the same error when the code goes into OTA update, it gives the not connected error
do i need to do any changes in this OTA.setBSSLBufferSize(4096 , 1024); ??

i m using three objects as follow

FirebaseData fbdo;
FirebaseData stream;
FirebaseData OTA;

some part as in setup()

  fbdo.setResponseSize(4096); // for trial made comment uncomment while testing if require

  fbdo.setBSSLBufferSize(4096 /* Rx buffer size in bytes from 512 - 16384 */, 1024 /* Tx buffer size in bytes from 512 - 16384 */);
  OTA.setBSSLBufferSize(4096 /* Rx buffer size in bytes from 512 - 16384 */, 1024 /* Tx buffer size in bytes from 512 - 16384 */);

  config.fcs.download_buffer_size = 8192;
// Recommend for ESP8266 stream, adjust the buffer size to match your stream data size
#if defined(ESP8266)
  stream.setBSSLBufferSize(2048 /* Rx in bytes, 512 - 16384 */, 512 /* Tx in bytes, 512 - 16384 */);
#endif
 Firebase.begin(&config, &auth);

for stream call back in setup()

  Firebase.RTDB.setMultiPathStreamCallback(&stream, streamCallback, streamTimeoutCallback);

for stream call back function defination

void streamCallback(MultiPathStream stream)
{
  size_t numChild = sizeof(childPath) / sizeof(childPath[0]);

  for (size_t i = 0; i < numChild; i++)
  {
    if (stream.get(childPath[i]))
    {
      char charArray[stream.dataPath.length() + 1];
      char valueArray[stream.value.length() + 1];
      strcpy(valueArray, stream.value.c_str());
      strcpy(charArray, stream.dataPath.c_str());

      /*================= FOR OTA UPDATE ========================= */
      
      if (strcmp(FIRMWARE_VERSION_LEVEL_TAG.c_str() , charArray) == 0 && strcmp("UPDATE", valueArray) == 0)
      {
        #if DEBUG
        Serial.println("FRIMWARE UPDATE HAVE BEEN REQUESTED....................");
        #endif
        OTA_REQUEST = 1;
      }

main loop code

void loop()
{
 if (OTA_REQUEST == UPDATE) //UPDATE = 1 defined in header file
 {
  OTA_UPDATE();
  OTA_REQUEST = 0; // reset value
 }

  // input_command_from_PC_GUI();

  if (Firebase.isTokenExpired())
  {
    Firebase.refreshToken(&config);
    #if DEBUG
    Serial.println("Refresh token");
    #endif
  }
  FLOOR_DETAIL();
  NORMAL_POWER_STANDBY();
  SEISMIC();
  Opertaion_Status();
  DIRECTION();
  FIREMAN_OPERATION();
  DO_DC();
  FIRE_ALARM_LAMP();
  Power_operation();
}

OTA_UPDATE function

void OTA_UPDATE()
{
    /*================================= CHECKING ONCE FIRMWARE UPDATE -- START ==================*/

 if (Firebase.ready() && !taskCompleted)
    {
        //taskCompleted = true;

        // If you want to get download url to use with your own OTA update process using core update library,
        // see Metadata.ino example
        #if DEBUG
        Serial.println("\nDownload firmware file...\n");
        #endif

        // This function will allocate 16k+ memory for internal SSL client.
        if (!Firebase.Storage.downloadOTA(&OTA, STORAGE_BUCKET_ID /* Firebase Storage bucket id */, REMOTE_FIRMWARE_LOCATION /* path of firmware file stored in the bucket */, fcsDownloadCallback /* callback function */))
            Serial.println(OTA.errorReason());
    }
 /*================================= CHECKING ONCE FIRMWARE UPDATE -- END ==================*/
}

fcs call back function

void fcsDownloadCallback(FCS_DownloadStatusInfo info)
{ 
  

    if (info.status == firebase_fcs_download_status_init)
    {Firebase.RTDB.setString(&fbdo, FIRMWARE_STATUS, "STARTED"); // for downloading status
        Serial.printf("Downloading firmware %s (%d)\n", info.remoteFileName.c_str(), info.fileSize);
    }
    else if (info.status == firebase_fcs_download_status_download)
    {
        Serial.printf("Downloaded %d%s, Elapsed time %d ms\n", (int)info.progress, "%", info.elapsedTime);
       Firebase.RTDB.setString(&fbdo, FIRMWARE_STATUS, (String)info.progress);// for downloading status
    }
    else if (info.status == firebase_fcs_download_status_complete)
    {
      
        #if DEBUG
        Serial.println("Update firmware completed.");
        Serial.println();
        Serial.println("Restarting...\n\n");
        #endif
         Firebase.RTDB.setString(&fbdo, FIRMWARE_STATUS, "COMPLETED--RESTARTING");// for downloading status
        delay(2000);
          #if defined(ESP32) || defined(ESP8266)
        ESP.restart();
          #elif defined(ARDUINO_RASPBERRY_PI_PICO_W)
        rp2040.restart();
        #endif
    }
    else if (info.status == firebase_fcs_download_status_error)
    {
        Serial.printf("Download firmware failed, %s\n", info.errorMsg.c_str());
         Firebase.RTDB.setString(&fbdo, FIRMWARE_STATUS, info.errorMsg);// for downloading status
    }
}

[mobizt]

You may have to increase the BearSSL rx buffer size to handle large payloads.

[mobizt]

For OTA, the rx buffer size (first parameter) should be 16384.

The tx buffer size can be any, 1024 is recommended.

[FurqanChaudhary]

I already tried increasing it to 16384.

[FurqanChaudhary]

i tried this

 OTA.setBSSLBufferSize(16384 /* Rx buffer size in bytes from 512 - 16384 */, 1024 /* Tx buffer size in bytes from 512 - 16384 */);

still same issue

[mobizt]

You have to check your free heap. It should be enough for 16 k+ .

It is possible for ESP32 and Raspberry Pi Pico W but not for other low memory devices.

[mobizt]

It is the amount of memory allocation at once the internal SSL client is initiated.

[mobizt]

You have to know that some ADC ports cannot be used while using WiFi otherwise the WiFi will not work.

You should not use delay in your code too because it blocks the server connection.