ESP WiFi hung solution

[fsgraz]

This is how I solved the issue of ESP32 GW hanging when WiFi connection is lost or not established. It is not 100% my original work, it has been put together using bits and pieces, but it works.

I simply use a watchdog timer:

#include "esp_system.h" // added for WDT
hw_timer_t* timer = NULL;

// WDT related
void IRAM_ATTR resetModule() {
	Serial.println("reboot\n");
	ESP.restart();
}

void WdtReset()
{
    timerWrite(timer, 0); //reset timer (feed watchdog)
}

void StartWatchDog()
{
    timer = timerBegin(0, 240, true); //timer 0, div 80
    timerAttachInterrupt(timer, &resetModule, true);
    timerAlarmWrite(timer, 5000000, false); //set time in us
    timerAlarmEnable(timer); //enable interrupt
}

IPAddress ConnectWiFi()
{
    Serial.println();
    Serial.println();
    Serial.print("Connecting to ");
    Serial.println(MY_WIFI_SSID);

    /* Explicitly set the ESP to be a WiFi-client, otherwise, it by default,
       would try to act as both a client and an access-point and could cause
       network-issues with your other WiFi-devices on your WiFi-network. */
#ifdef ESP32
    WiFi.persistent(false);
    WiFi.mode(WIFI_STA);
#endif // ESP32

    WiFi.begin(MY_WIFI_SSID, MY_WIFI_PASSWORD);


    while (WiFi.status() != WL_CONNECTED) {
        digitalWrite(LED_BUILTIN, LED_ON);
        wait(500);
        Serial.print(".");
        digitalWrite(LED_BUILTIN, LED_OFF);
        wait(500);
    }

#ifdef ESP32
    WiFi.setAutoReconnect(true);
#endif // ESP32

    return WiFi.localIP();
    
}
void before()
{

    StartWatchDog();

    // We start by connecting to a WiFi network
    localIP = ConnectWiFi();
    myHostname = WiFi.getHostname();

    WdtReset();

    Serial.println("");
    Serial.println("WiFi connected");
    Serial.println("IP address: ");
    Serial.println(localIP);
    Serial.println(myHostname);

// do other stuff ...

}

void loop()
{
   

    // check WiFi connection
    if (WiFi.status() != WL_CONNECTED) return; // the WDT is not reset
    WdtReset();

// do other stuff ...
}

Hope it helps