Wifi automatic reconnection issue with ESP32

1technophile · December 7, 2019, 7:20am

Continuing the discussion from ESP32 BLE gateway dying every day and a half:

I prefer to separate the topic so as to narrow down the issue (strictly the fact that the gateway doesn’t reconnect automaticaly to wifi with certain router is in my point of view a different issue compared to BLE stability)

I have added a modification to the branch below:
https://github.com/1technophile/OpenMQTTGateway/tree/wifi-reconnect-when-scan

Related to this issue on ESP32:

github.com/espressif/arduino-esp32

ESP32 WiFi.begin works only every second time - workaround

opened 10:49AM - 24 Feb 19 UTC

closed 02:47PM - 28 Feb 22 UTC

DIRR70

Area: BT&Wifi Status: Awaiting triage

### Hardware: Board: ESP32-WROOM-32 Dev Module Core Installation versio…n: 1.0.1 (installed using board manager feb/23) IDE name: Arduino IDE 1.88 CPU Frequency: 80MHz Flash Frequency: 40Mhz Flash Mode: QIO Flash Size: 2MB (16MB) Partition Scheme: Standard PSRAM enabled: no Upload Speed: 921600 Computer OS: Windows 10 ### Description: With a portable device I need to ensure that WiFi connection is beeing established as soon as the router is in range. Also I need to do some stuff as soon the connection is established or lost (in my sketch below just a serial output). I have the problem that "WiFi.begin(ssid, pass)" works only every second time. If it doesn't work, I have to press the reset button and then it works. If I press reset again it won't work. Pressing reset again and it works, and so on. If it doesn't work I get the following output with Debug Level set to verbose: [W][WiFiGeneric.cpp:357] _eventCallback(): Reason: 202 - AUTH_FAIL My router is a Fritz! Box 6490 cable and even though I've checked the router's options I can't find anything wrong. Regarding to familiar posts I even have tried with a regulated power supply at 5V (current limit 2.5A) - but no change. I came up with a workaround with a task checking the connection and that works pretty well. In case of "WiFi.status" turns to "WL_CONNECT_FAILED" I need to call "WiFi.disconnect(true)" and a bit later "WiFi.begin" again. About the whole working sketch below I have several questions: 1. Is that "works/doesn't work" behaviour a firmware bug, a bug in arduino or this SDK or a router problem? 2. In my sketch I'm using "xTaskCreatePinnedToCore" for the connection watching task. How large does the stack for that task need to be (seems to work with 8kB) and what priority does such a task need to have (I just took 3 to be higher than IDLE)? 3. I never got "WL_CONNECTION_LOST" as Wifi status. Do I need to consider that? And if so, how? Please advise! Thank's! ### Sketch: ```cpp #include <WiFi.h> const char* ssid = "..."; const char* password = "..."; bool myWiFiFirstConnect = true; void myWiFiTask(void *pvParameters) { wl_status_t state; while (true) { state = WiFi.status(); if (state != WL_CONNECTED) { // We have no connection if (state == WL_NO_SHIELD) { // WiFi.begin wasn't called yet Serial.println("Connecting WiFi"); WiFi.mode(WIFI_STA); WiFi.begin(ssid, password); } else if (state == WL_CONNECT_FAILED) { // WiFi.begin has failed (AUTH_FAIL) Serial.println("Disconnecting WiFi"); WiFi.disconnect(true); } else if (state == WL_DISCONNECTED) { // WiFi.disconnect was done or Router.WiFi got out of range if (!myWiFiFirstConnect) { // Report only once myWiFiFirstConnect = true; Serial.println("WiFi disconnected"); } } vTaskDelay (250); // Check again in about 250ms } else { // We have connection if (myWiFiFirstConnect) { // Report only once myWiFiFirstConnect = false; Serial.print("Connected to "); Serial.println(ssid); Serial.print("IP address: "); Serial.println(WiFi.localIP()); Serial.println(""); } vTaskDelay (5000); // Check again in about 5s } } } void setup() { delay(1000); // Power up Serial.begin(115200); // Create a connection task with 8kB stack on core 0 xTaskCreatePinnedToCore(myWiFiTask, "myWiFiTask", 8192, NULL, 3, NULL, 0); } void loop() { } ``` ### Debug Messages: ``` If WiFi.begin works: [D][WiFiGeneric.cpp:342] _eventCallback(): Event: 0 - WIFI_READY [D][WiFiGeneric.cpp:342] _eventCallback(): Event: 2 - STA_START ....[D][WiFiGeneric.cpp:342] _eventCallback(): Event: 4 - STA_CONNECTED [D][WiFiGeneric.cpp:342] _eventCallback(): Event: 7 - STA_GOT_IP [D][WiFiGeneric.cpp:385] _eventCallback(): STA IP: 192.168.178.21, MASK: 255.255.255.0, GW: 192.168.178.1 If it doesn't work: [D][WiFiGeneric.cpp:342] _eventCallback(): Event: 0 - WIFI_READY [D][WiFiGeneric.cpp:342] _eventCallback(): Event: 2 - STA_START [D][WiFiGeneric.cpp:342] _eventCallback(): Event: 5 - STA_DISCONNECTED [W][WiFiGeneric.cpp:357] _eventCallback(): Reason: 202 - AUTH_FAIL ```

krambriw · December 7, 2019, 11:45am

Hello, good news, it seems working fine now!

When the AP is down I see in log the following coming repeatedly:

MQTT client disconnected no BLE scan
*WM: [2] [EVENT] WIFI_REASON: 201
*WM: [2] [EVENT] WIFI_REASON: NO_AP_FOUND
BT Task running on core 0
*WM: [2] [EVENT] WIFI_REASON: 201
*WM: [2] [EVENT] WIFI_REASON: NO_AP_FOUND
MQTT connection…
[E][WiFiClient.cpp:232] connect(): connect on fd 55, errno: 118, “Host is unreachable”
failure_number
81
failed, rc=
-2

When the AP is up again, a new connection is made successfully, mqtt publishing starts again, everything is fine. Tried this several times and every time the ESP32 recovers the wifi connection successfully

One thing I noticed with previous versions was the the BT scanning (until it was turned off in last versions when there was no mqtt connection) always seemed to work even if the wifi was disconnected. So could this wifi disconnect, if it happened for any reason, actually have been the cause why the gateway was experienced as “dead”?

What I mean here is that one type of behavior (mqtt publishing ended) could have been caused by a another problem, i.e. temporary wifi connection error that was never recovered

Anyway, time will tell, so far it looks really good!!

PS In the serial monitor I see several devices being found, including my sonos speakers, but for some reason the text (manufacturerdata) is not readable, is it something in the platformio that can be adjusted, like supporting character set utf-8 or so? Or is it in the actual code where you publish the results to mqtt?

{“id”:“f3:33:41:94:64:d5”,“manufacturerdata”:“�␅␃␑Sonos_Uq9RJ”,“rssi”:-84,“txpower”:0,“distance”:

{“id”:“f3:33:ac:c2:d7:6e”,“manufacturerdata”:“�␅␃␒u1w1PbgkSBO”,“rssi”:-87,“txpower”:0,“distance”:

{“id”:“f3:33:ac:c2:d7:6e”,“manufacturerdata”:“�␅␃␐␁�Dޭ��”,“rssi”:-87,“txpower”:0,“distance”:18.07

1technophile · December 7, 2019, 11:55am

Great, thanks for helping me debug this!

I need some investigations so as to see what happens here