Merge pull request #157 from kharnt0x/wifi-fix

Better handling of wifi events, by @kharnt0x

Software/src/devboard/webserver/webserver.cpp

@@ -36,15 +36,21 @@ const char index_html[] PROGMEM = R"rawliteral(
 </html>
 )rawliteral";
 
-String wifi_state;
-bool wifi_connected;
-
 // Wifi connect time declarations and definition
-unsigned long wifi_connect_start_time;
+const unsigned long MAX_WIFI_RECONNECT_BACKOFF_TIME = 60000;  // Maximum backoff time of 1 minute
-unsigned long wifi_connect_current_time;
+const unsigned long DEFAULT_WIFI_RECONNECT_BACKOFF_TIME =
-unsigned long wifi_connect_timeout = 5000;     // Timeout for WiFi connect in milliseconds
+    1000;                                          // Default wifi reconnect backoff time. Start with 1 second
-unsigned long wifi_monitor_loop_time = 30000;  // Will check if WiFi is connected and try reconnect every x milliseconds
+const unsigned long WIFI_CONNECT_TIMEOUT = 10000;  // Timeout for WiFi connect in milliseconds
+const unsigned long WIFI_MONITOR_LOOP_TIME =
+    1000;  // Will check if WiFi is connected and try reconnect every x milliseconds
 unsigned long last_wifi_monitor_run = 0;
+unsigned long wifi_connect_start_time;
+unsigned long wifi_reconnect_backoff_time = DEFAULT_WIFI_RECONNECT_BACKOFF_TIME;
+
+enum WiFiState { DISCONNECTED, CONNECTING, CONNECTED };
+
+WiFiState wifi_state =
+    DISCONNECTED;  //the esp library has no specific state to indicate if its connecting (only WL_IDLE_STATUS) so we keep track of it here
 
 void init_webserver() {
   // Configure WiFi
@@ -249,79 +255,123 @@ void init_webserver() {
 #endif
 }
 
+void print_wifi_status_message(wl_status_t status) {
+  switch (status) {
+    case WL_CONNECTED:
+      Serial.println("Connected to WiFi network: " + String(ssid));
+      Serial.println("IP address: " + WiFi.localIP().toString());
+      Serial.println("Signal Strength: " + String(WiFi.RSSI()) + " dBm");
+      break;
+    case WL_CONNECT_FAILED:
+      Serial.println("Failed to connect to WiFi network: " + String(ssid));
+      break;
+    case WL_CONNECTION_LOST:
+      Serial.println("Connection to WiFi network: " + String(ssid) + " lost");
+      break;
+    case WL_DISCONNECTED:
+      Serial.println("Disconnected from WiFi network: " + String(ssid));
+      break;
+    case WL_NO_SSID_AVAIL:
+      Serial.println("Could not find network with SSID: " + String(ssid));
+      break;
+    case WL_IDLE_STATUS:
+      Serial.println("WiFi is in idle status. This can indicate it is currently trying to connect.");
+      break;
+    case WL_SCAN_COMPLETED:
+      Serial.println("WiFi scan completed");
+      break;
+    case WL_NO_SHIELD:
+      Serial.println("No WiFi shield detected");
+      break;
+    default:
+      Serial.println("Unknown WiFi status: " + String(status));
+      break;
+  }
+}
+
+// Function to handle WiFi reconnection. Use some timeouts and backoffs here to avoid flooding reconnection attempts/spamming the serial console
+void handle_WiFi_reconnection(unsigned long currentMillis, wl_status_t status) {
+  if (wifi_state == CONNECTING && currentMillis - wifi_connect_start_time > WIFI_CONNECT_TIMEOUT) {
+    // we are here if we were trying to connect to wifi, but it took too long (more than configured timeout)
+    Serial.println("Failed to connect to WiFi network before timeout");
+    print_wifi_status_message(status);
+    WiFi.disconnect();  //disconnect to clear any previous settings
+    wifi_state = DISCONNECTED;
+    wifi_connect_start_time = currentMillis;  //reset the start time to now so backoff is respected on next try
+    // We use a backoff time before trying to connect again. Increase backoff time, up to a maximum
+    wifi_reconnect_backoff_time = min(wifi_reconnect_backoff_time * 2, MAX_WIFI_RECONNECT_BACKOFF_TIME);
+    Serial.println("Will try again in " + String(wifi_reconnect_backoff_time / 1000) + " seconds.");
+  } else if (wifi_state != CONNECTING && currentMillis - wifi_connect_start_time > wifi_reconnect_backoff_time) {
+    // we are here if the connection failed for some reason and the backoff time has now passed
+    print_wifi_status_message(status);
+    init_WiFi_STA(ssid, password);
+  }
+}
+
+// Function to handle WiFi connection
 void WiFi_monitor_loop() {
   unsigned long currentMillis = millis();
-  if (currentMillis - last_wifi_monitor_run > wifi_monitor_loop_time) {
+  if (currentMillis - last_wifi_monitor_run > WIFI_MONITOR_LOOP_TIME) {
     last_wifi_monitor_run = currentMillis;
-    if (WiFi.status() != WL_CONNECTED && wifi_state != "Connecting") {
+    wl_status_t status = WiFi.status();
-      wifi_connected = false;
+    switch (status) {
-      wifi_state = "Not connected";
+      case WL_CONNECTED:
-      Serial.print("Wifi disconnected. Attempting reconnection");
+        if (wifi_state != CONNECTED) {  //we need to update our own wifi state to indicate we are connected
-      init_WiFi_STA(ssid, password);
+          wifi_reconnect_backoff_time =
-    } else if (WiFi.status() == WL_CONNECTED && wifi_state != "Connected") {
+              DEFAULT_WIFI_RECONNECT_BACKOFF_TIME;  // Reset backoff time after maintaining connection
-      wifi_connected = true;
+          wifi_state = CONNECTED;
-      wifi_state = "Connected";
+          print_wifi_status_message(status);
-      Serial.println("Wifi reconnected");
+        }
+        break;
+      case WL_CONNECT_FAILED:
+      case WL_CONNECTION_LOST:
+      case WL_DISCONNECTED:
+      case WL_NO_SSID_AVAIL:
+        handle_WiFi_reconnection(currentMillis, status);
+        break;
+      case WL_IDLE_STATUS:  //this means the wifi is not ready to process any commands (it's probably trying to connect). do nothing
+
+      case WL_SCAN_COMPLETED:  //this will only be set when scanning for networks. We don't do that yet
+      case WL_NO_SHIELD:       //should not happen, this means no wifi chip detected, so we can't do much
+        break;
     }
   }
 }
 
+// Function to initialize WiFi in Station Mode (i.e. connect to another access point)
+void init_WiFi_STA(const char* ssid, const char* password) {
+  Serial.println("Connecting to: " + String(ssid));
+  wifi_state = CONNECTING;
+  WiFi.begin(ssid, password);
+  WiFi.setAutoReconnect(true);
+  wifi_connect_start_time = millis();
+}
+
+// Function to convert WiFiState enum to String
+String wifi_state_to_string(WiFiState state) {
+  switch (state) {
+    case DISCONNECTED:
+      return "Disconnected";
+    case CONNECTING:
+      return "Connecting";
+    case CONNECTED:
+      return "Connected";
+    default:
+      return "Unknown";
+  }
+}
+
+// Function to initialize WiFi in Access Point Mode
 void init_WiFi_AP() {
-  Serial.print("Creating Access Point: ");
+  Serial.println("Creating Access Point: " + String(ssidAP));
-  Serial.println(ssidAP);
+  Serial.println("With password: " + String(passwordAP));
-  Serial.print("With password: ");
-  Serial.println(passwordAP);
-
   WiFi.softAP(ssidAP, passwordAP);
-
   IPAddress IP = WiFi.softAPIP();
   Serial.println("Access Point created.");
-  Serial.print("IP address: ");
+  Serial.println("IP address: " + IP.toString());
-  Serial.println(IP);
-}
-
-void init_WiFi_STA(const char* ssid, const char* password) {
-  // If we're already connected, there's nothing to do
-  if (WiFi.status() == WL_CONNECTED) {
-    if (wifi_state != "Connected") {
-      wifi_connected = true;
-      wifi_state = "Connected";
-      // Print local IP address and start web server
-      Serial.println("");
-      Serial.print("Connected to WiFi network: ");
-      Serial.println(ssid);
-      Serial.print("IP address: ");
-      Serial.println(WiFi.localIP());
-    }
-    return;
-  }
-
-  // If we're not currently trying to connect, start the connection process
-  if (wifi_state != "Connecting") {
-    Serial.print("Connecting to: ");
-    Serial.println(ssid);
-    WiFi.begin(ssid, password);
-    wifi_state = "Connecting";
-    wifi_connect_start_time = millis();
-    return;
-  }
-
-  // If we've been trying to connect for more than 5000ms, give up
-  if (millis() - wifi_connect_start_time > wifi_connect_timeout) {
-    wifi_state = "Not connected";
-    Serial.print("Failed to connect to WiFi network: ");
-    Serial.println(ssid);
-    Serial.println("Please check WiFi network name and password, and if WiFi network is available.");
-    Serial.print("Will try again in ");
-    Serial.print((wifi_monitor_loop_time - (millis() - last_wifi_monitor_run)) / 1000);
-    Serial.println(" seconds.");
-    return;
-  }
-
-  // Otherwise, just print a dot to indicate that we're still trying to connect
-  Serial.print(".");
 }
 
+// Function to initialize ElegantOTA
 void init_ElegantOTA() {
   ElegantOTA.begin(&server);  // Start ElegantOTA
   // ElegantOTA callbacks
@@ -367,8 +417,8 @@ String processor(const String& var) {
     }
     // Display ssid of network connected to and, if connected to the WiFi, its own IP
     content += "<h4>SSID: " + String(ssid) + "</h4>";
-    content += "<h4>Wifi status: " + wifi_state + "</h4>";
+    content += "<h4>Wifi status: " + wifi_state_to_string(wifi_state) + "</h4>";
-    if (wifi_connected == true) {
+    if (WiFi.status() == WL_CONNECTED) {
       content += "<h4>IP: " + WiFi.localIP().toString() + "</h4>";
       // Get and display the signal strength (RSSI)
       content += "<h4>Signal Strength: " + String(WiFi.RSSI()) + " dBm</h4>";

Software/src/devboard/webserver/webserver.h

@@ -90,6 +90,15 @@ void init_WiFi_STA(const char* ssid, const char* password);
  */
 void WiFi_monitor_loop();
 
+// /**
+//  * @brief Function to handle WiFi reconnection.
+//  *
+//  * @param[in] void
+//  *
+//  * @return void
+//  */
+// void handle_WiFi_reconnection(unsigned long currentMillis);
+
 /**
  * @brief Initialization function for ElegantOTA.
  *