Hieromon
commented
5 years ago @Adrian8x, It is worthwhile to consider the mechanism by which the module detects the situation you encounter and recovers itself.
ESP-IDF says: https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/wifi.html?highlight=reconnect#wifi-event-sta-disconnected
But, there are two things we need to be aware of to deal with this phenomenon.
- By ESP32 core, No SYSTEM_EVENT_STA_DISCONNECTED event occurs if the WiFi data link lost due to a power failure of the router, etc.
- ESP32 core will reconnect if it is just a WiFi disconnect.
Even if a power failure of the router occurs, ESP32 will reconnect since the router will recover the WiFi radio signal after the power of the router restored. If you have a cell phone that supports WiFi dithering, you can use it as a simple router and check the WiFi recovery sequence using the WiFiClientEvents.ino contained in WiFiClientEvents example of the ESP32 core library.
However, as you have experienced, if the WiFi data link does not recover even if the router recovers, you need to reconnect intentionally with a sketch. I have a suggestion that the module detects the WiFi disconnection event itself.
Polling the WiFi status, reset the module.
wl_status_t WIFIStatus;
unsigned long StablePeriod;
void checkStateChange() {
wl_status_t st = WiFi.status();
if (WIFIStatus != st && st != WL_NO_SSID_AVAIL) {
Serial.printf("Status changed:%d->%d, %ld\n", WIFIStatus, WiFi.status(), StablePeriod);
WIFIStatus = WiFi.status();
StablePeriod = millis();
}
else if (WIFIStatus == WL_DISCONNECTED) {
// If disconnected state maintains while 60 seconds,
// wait 3 minutes to reset the module
if (millis() - StablePeriod > (60 * 1000)) {
Serial.println("WiFi disconnected, enter deep sleep.");
esp_sleep_enable_timer_wakeup(3 * 60 * 1000 * 1000);
esp_deep_sleep_start();
}
}
}
void setup() {
delay(1000);
Serial.begin(115200);
portal.begin();
WIFIStatus = WiFi.status(); // set status to the connected
StablePeriod = millis();
}
void loop() {
checkStateChange();
portal.handleClient();
}
If you can try this solution, please let me know the results. I think the problem and solution you have experienced is beneficial to other users and would like to reflect the results in the documentation if you have solved the problem.
Adrian8x
Hello Hieromon,
I'm running in some problem's with ESP32 using AutoConnect. I can access the captive portal, the WiFi ssid and password are saved OK but I have trouble when my router power is disconnected or when there is a blackout. The ESP doesn't reconnect automatically to the last saved credentials when the power come back, if I not reset the ESP32 manually. The ESP is powered with batteries so it is not restarted with the router when a blackout occur. There is a specific configuration for that?
I use Arduino 1.8.9 and AutoConnect 0.9.10 with ESP32 DEVKIT v.1
Thank you!