WiFi on ESP32 does not reconnect after many network drops

filipekerplunk · June 10, 2022, 9:33pm

Hi!

I have two ESP32, one of them, when the internet network is bad and constantly dropping, at some point this ESP32 stops automatically reconnecting to WiFi.
Even rebooting by the EN button, it doesn't reconnect anymore, only if i turn it off and on again on power.

Searching I didn't find any answer that explained the reason, is there any condition that the ESP32 WiFi chip doesn't reboot together? The impression I get is that it only reboots the wifi issue when I turn it off.

I can't confirm because I'm new to ESP32, but could anyone tell me something about it? Or do you have a theory of why?

Thanks!

Idahowalker · June 10, 2022, 9:45pm

If you could post your code, that would be great.

Here is how I connect to WiFI with ESp32's.

void connectToWiFi()
{
  int TryCount = 0;
  while ( WiFi.status() != WL_CONNECTED )
  {
    TryCount++;
    WiFi.disconnect();
    WiFi.begin( SSID, PASSWORD );
    vTaskDelay( 4000 );
    if ( TryCount == 10 )
    {
      ESP.restart();
    }
  }
  WiFi.onEvent( WiFiEvent );
} // void connectToWiFi()
//////

Perhaps it may help.

filipekerplunk · June 10, 2022, 10:16pm

I use a WiFiManager library to save the data.
(GitHub - khoih-prog/ESP_WiFiManager: This is an ESP32 / ESP8266 WiFi Connection Manager with fallback web configuration portal. Use this library for configuring ESP32 (including ESP32-S2 and ESP32-C3), ESP8266 modules' WiFi, etc. Credentials at runtime. You can also specify static DNS servers, personalized HostName, fixed or random AP WiFi channel. With examples supporting ArduinoJson)

The sketch only checks whether it is connected or not, if not, it restarts after 2 minutes:

#include <WiFiClient.h>
#include <ESP_WiFiManager.h>

#define ESP_getChipId()   ((uint32_t)ESP.getEfuseMac())

#include <timeObj.h>
timeObj timeMax(120 * 1000.0);

// SSID and PW for Config Portal
String ssid = "ESP_" + String(ESP_getChipId(), HEX);
const char* password = "your_password";
// SSID and PW for your Router
String Router_SSID;
String Router_Pass;
// Indicates whether ESP has WiFi credentials saved from previous session
bool initialConfig = false;
// Use true for dynamic DHCP IP, false to use static IP and  you have to change the IP accordingly to your network
#define USE_DHCP_IP     true
// Use DHCP
IPAddress stationIP   = IPAddress(0, 0, 0, 0);
IPAddress gatewayIP   = IPAddress(192, 168, 2, 1);
IPAddress netMask     = IPAddress(255, 255, 255, 0);
IPAddress dns1IP      = gatewayIP;
IPAddress dns2IP      = IPAddress(8, 8, 8, 8);

bool shouldSaveConfig = false;

int millisTarefa1;

void heartBeatPrint(void)
{
  static int num = 1;

  if (WiFi.status() == WL_CONNECTED)
    Serial.print("H");        // H means connected to WiFi
  else
    Serial.print("F");        // F means not connected to WiFi

  if (num == 80)
  {
    Serial.println();
    num = 1;
  }
  else if (num++ % 10 == 0)
  {
    Serial.print(" ");
  }
}


/*FUNÇÃO QUE CONECTA O ESP32 A REDE WIFI*/
void check_status() {
  // is configuration portal requested?
  Serial.println("\nConfiguration portal requested.");
  //Local intialization. Once its business is done, there is no need to keep it around
  ESP_WiFiManager ESP_wifiManager;
  ESP_wifiManager.setSaveConfigCallback(saveConfigCallback);

  //Check if there is stored WiFi router/password credentials.
  //If not found, device will remain in configuration mode until switched off via webserver.
  Serial.print("Opening configuration portal. ");
  Router_SSID = ESP_wifiManager.WiFi_SSID();
  if (Router_SSID != "")
  {
    ESP_wifiManager.setConfigPortalTimeout(120); //If no access point name has been previously entered disable timeout.
    Serial.println("Got stored Credentials. Timeout 120s");
  }
  else
    Serial.println("No stored Credentials. No timeout");


  ESP_wifiManager.setMinimumSignalQuality(-1);
  // Set static IP, Gateway, Subnetmask, DNS1 and DNS2. New in v1.0.5
  ESP_wifiManager.setSTAStaticIPConfig(stationIP, gatewayIP, netMask, dns1IP, dns2IP);

  //it starts an access point
  //and goes into a blocking loop awaiting configuration
  if (!ESP_wifiManager.startConfigPortal((const char *) ssid.c_str(), password))
  {
    Serial.println("Not connected to WiFi but continuing anyway.");
  }
  else
  {
    //if you get here you have connected to the WiFi
    Serial.println("connected...yeey :)");
    Serial.print("Local IP: ");
    Serial.println(WiFi.localIP());
  }


  static ulong checkstatus_timeout = 0;
#define HEARTBEAT_INTERVAL    10000L
  // Print hearbeat every HEARTBEAT_INTERVAL (10) seconds.
  if ((millis() > checkstatus_timeout) || (checkstatus_timeout == 0))
  {
    heartBeatPrint();
    checkstatus_timeout = millis() + HEARTBEAT_INTERVAL;
  }
}

void saveConfigCallback () {
  Serial.println("Should save config");
  shouldSaveConfig = true;
}

void connectWifi() {

  Serial.println("\nStarting ConfigOnSwitch on " + String(ARDUINO_BOARD));

  unsigned long startedAt = millis();

  //Local intialization. Once its business is done, there is no need to keep it around
  // Use this to default DHCP hostname to ESP8266-XXXXXX or ESP32-XXXXXX
  //ESP_WiFiManager ESP_wifiManager;
  // Use this to personalize DHCP hostname (RFC952 conformed)
  ESP_WiFiManager ESP_wifiManager("ConfigOnSwitch");

  ESP_wifiManager.setDebugOutput(true);

  // Use only to erase stored WiFi Credentials
  //resetSettings();
  //ESP_wifiManager.resetSettings();

  //set custom ip for portal
  //ESP_wifiManager.setAPStaticIPConfig(IPAddress(192, 168, 100, 1), IPAddress(192, 168, 100, 1), IPAddress(255, 255, 255, 0));

  ESP_wifiManager.setMinimumSignalQuality(-1);

  // We can't use WiFi.SSID() in ESP32as it's only valid after connected.
  // SSID and Password stored in ESP32 wifi_ap_record_t and wifi_config_t are also cleared in reboot
  // Have to create a new function to store in EEPROM/SPIFFS for this purpose
  Router_SSID = ESP_wifiManager.WiFi_SSID();
  Router_Pass = ESP_wifiManager.WiFi_Pass();

  //Remove this line if you do not want to see WiFi password printed
  Serial.println("Stored: SSID = " + Router_SSID + ", Pass = " + Router_Pass);

  // SSID to uppercase
  ssid.toUpperCase();

  if (Router_SSID == "")
  {
    Serial.println("Open Config Portal without Timeout: No stored Credentials.");



    //it starts an access point
    //and goes into a blocking loop awaiting configuration
    if (!ESP_wifiManager.startConfigPortal((const char *) ssid.c_str(), password))
      Serial.println("Not connected to WiFi but continuing anyway.");
    else
      Serial.println("WiFi connected...yeey :)");
  }



#define WIFI_CONNECT_TIMEOUT        30000L
#define WHILE_LOOP_DELAY            200L
#define WHILE_LOOP_STEPS            (WIFI_CONNECT_TIMEOUT / ( 3 * WHILE_LOOP_DELAY ))

  startedAt = millis();

  while ( (WiFi.status() != WL_CONNECTED) && (millis() - startedAt < WIFI_CONNECT_TIMEOUT ) )
  {
    WiFi.mode(WIFI_STA);
    WiFi.persistent (true);

    // We start by connecting to a WiFi network

    Serial.print("Connecting to ");
    Serial.println(Router_SSID);

    WiFi.config(stationIP, gatewayIP, netMask);
    //WiFi.config(stationIP, gatewayIP, netMask, dns1IP, dns2IP);

    WiFi.begin(Router_SSID.c_str(), Router_Pass.c_str());

    int i = 0;
    while ((!WiFi.status() || WiFi.status() >= WL_DISCONNECTED) && i++ < WHILE_LOOP_STEPS)
    {
      delay(WHILE_LOOP_DELAY);
    }
  }

  Serial.print("After waiting ");
  Serial.print((millis() - startedAt) / 1000);
  Serial.println(" secs more in setup(), connection result is ");

  if (WiFi.status() == WL_CONNECTED)
  {
    Serial.print("connected. Local IP: ");
    Serial.println(WiFi.localIP());

  }
}

void streamTimeoutCallback(bool timeout)
{
  if (timeout) {
    //Stream timeout occurred
    Serial.println("Stream timeout, resume streaming...");
  }
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(0, INPUT);
  if (digitalRead(0) == LOW)
  {
    Serial.println("Configure WIFI Manager...");
    check_status();
  }
  connectWifi();
  delay(2000);
  if (WiFi.status() == WL_CONNECTED) {
    timeMax.start();
  }
  Serial.println("Setup end...");
}

void loop() {
  // put your main code here, to run repeatedly:

  if (WiFi.status() == WL_CONNECTED) {
    Serial.println("Conected");
  }
  else {
    Serial.println("Disconected");
    if (timeMax.ding()) { //2 minutes
      ESP.restart();
    }
  }
}

Idahowalker · June 10, 2022, 10:29pm

The biggest cause of WiFI issues with these little MCU is WiFi Stack corruption.

Does 2 things.

If connected disconnect.

Resets the WiFi Stack.

filipekerplunk · June 12, 2022, 4:20pm

But theoretically wouldn't ESP.restart() handle WiFi stack corruption?

Idahowalker · June 12, 2022, 4:27pm

Yes.

filipekerplunk · June 12, 2022, 4:33pm

So, but in my case it doesn't return alone until I reset by command or by EN, only if I reset by removing the power and turning it on again. Somehow the WiFi chip doesn't reset when ESP32 resets by command and that's what I'm trying to understand why but I still haven't found answers.

system · December 9, 2022, 4:34pm

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.

Topic		Replies	Views
ESP32S2 and reconnect to wifi Programming	3	138	January 3, 2025
Esp32 keeps rebooting if i use wifi connection 3rd Party Boards	14	8269	September 14, 2024
ESP32 wifi getting disconnected once within 3-4 days 3rd Party Boards	3	1347	July 16, 2023
ESP32 logger wifi issues General Guidance	6	1735	December 22, 2022
Problem with reconnect wifi Programming	2	705	January 11, 2022

WiFi on ESP32 does not reconnect after many network drops

Related topics