Optimise wifi scan

- prioritize strongest signal
- prune removed networks
- fill present networks

wled00/data/settings_wifi.htm

@@ -52,8 +52,9 @@
 				}
 				scanLoops = 0;
 
-				let cs = d.querySelectorAll("#wifi_entries input[type=text]#CS0");
+				let cs = d.querySelectorAll("#wifi_entries input[type=text]");
 				for (let input of (cs||[])) {
+					let found = false;
 					let select = cE("select");
 					select.id = input.id;
 					select.name = input.name;
@@ -72,6 +73,7 @@
 
 						if (networks[i].ssid === input.value) {
 							option.setAttribute("selected", "selected");
+							found = true;
 						}
 
 						select.appendChild(option);
@@ -82,7 +84,8 @@
 					option.textContent = "Other network...";
 					select.appendChild(option);
 
-					input.replaceWith(select);
+					if (input.value === "" || found) input.replaceWith(select);
+					else select.remove(); 
 				}
 
 				button.disabled = false;

wled00/data/style.css

@@ -81,6 +81,7 @@ input:disabled {
 }
 input[type="text"],
 input[type="number"],
+input[type="password"],
 select {
     font-size: medium;
     margin: 2px;

wled00/set.cpp

@@ -19,8 +19,7 @@ void handleSettingsSet(AsyncWebServerRequest *request, byte subPage)
   //WIFI SETTINGS
   if (subPage == SUBPAGE_WIFI)
   {
-    char oldSSID[33];
-    strlcpy(oldSSID, multiWiFi[0].clientSSID, 33);
+    unsigned cnt = 0;
     for (size_t n = 0; n < WLED_MAX_WIFI_COUNT; n++) {
       char cs[4] = "CS"; cs[2] = 48+n; cs[3] = 0; //client SSID
       char pw[4] = "PW"; pw[2] = 48+n; pw[3] = 0; //client password
@@ -28,10 +27,11 @@ void handleSettingsSet(AsyncWebServerRequest *request, byte subPage)
       char gw[5] = "GW"; gw[2] = 48+n; gw[4] = 0; //GW address
       char sn[5] = "SN"; sn[2] = 48+n; sn[4] = 0; //subnet mask
       if (request->hasArg(cs)) {
-        if (n >= multiWiFi.size()) multiWiFi.push_back(WiFiConfig());
+        if (n >= multiWiFi.size()) multiWiFi.push_back(WiFiConfig()); // expand vector by one
         char oldSSID[33]; strcpy(oldSSID, multiWiFi[n].clientSSID);
         char oldPass[65]; strcpy(oldPass, multiWiFi[n].clientPass);
-        if (!strncmp(request->arg(cs).c_str(), oldSSID, 32)) {
+
+        if (strlen(oldSSID) == 0 || !strncmp(request->arg(cs).c_str(), oldSSID, 32)) {
           strlcpy(multiWiFi[n].clientSSID, request->arg(cs).c_str(), 33);
           forceReconnect = true;
         }
@@ -47,18 +47,24 @@ void handleSettingsSet(AsyncWebServerRequest *request, byte subPage)
           multiWiFi[n].staticGW[i] = request->arg(gw).toInt();
           multiWiFi[n].staticSN[i] = request->arg(sn).toInt();
         }
+        cnt++;
       }
     }
+    // remove unused
+    if (cnt < multiWiFi.size()) {
+      cnt = multiWiFi.size() - cnt;
+      while (cnt--) multiWiFi.pop_back();
+      multiWiFi.shrink_to_fit(); // release memory
+    }
 
     if (request->hasArg(F("D0"))) {
       dnsAddress = IPAddress(request->arg(F("D0")).toInt(),request->arg(F("D1")).toInt(),request->arg(F("D2")).toInt(),request->arg(F("D3")).toInt());
-      DEBUG_PRINTLN(dnsAddress);
     }
 
     strlcpy(cmDNS, request->arg(F("CM")).c_str(), 33);
 
     apBehavior = request->arg(F("AB")).toInt();
-    strcpy(oldSSID, apSSID);
+    char oldSSID[33]; strcpy(oldSSID, apSSID);
     strlcpy(apSSID, request->arg(F("AS")).c_str(), 33);
     if (!strcmp(oldSSID, apSSID) && apActive) forceReconnect = true;
     apHide = request->hasArg(F("AH"));

wled00/wled.cpp

@@ -453,6 +453,8 @@ void WLED::setup()
   WiFi.onEvent(WiFiEvent);
   #endif
 
+  findWiFi(true); // start scanning for available WiFi-s
+
   #ifdef WLED_ENABLE_ADALIGHT
   //Serial RX (Adalight, Improv, Serial JSON) only possible if GPIO3 unused
   //Serial TX (Debug, Improv, Serial JSON) only possible if GPIO1 unused
@@ -698,7 +700,48 @@ bool WLED::initEthernet()
 #else
   return false; // Ethernet not enabled for build
 #endif
+}
 
+// performs asynchronous scan for available networks (which may take couple of seconds to finish)
+// returns true if only one wifi is configured or scan completed
+bool WLED::findWiFi(bool doScan) {
+  if (multiWiFi.size() <= 1) {
+    DEBUG_PRINTLN(F("Defaulf WiFi used."));
+    selectedWiFi = 0;
+    return true;
+  }
+
+  if (doScan) WiFi.scanDelete();  // restart scan
+
+  int status = WiFi.scanComplete();
+
+  if (status == WIFI_SCAN_FAILED) {
+    DEBUG_PRINTLN(F("WiFi scan started."));
+    WiFi.scanNetworks(true);  // start scanning in asynchronous mode
+    return false;
+  }
+  if (status > 0) { // status contains number of found networks
+    DEBUG_PRINT(F("WiFi scan completed: ")); DEBUG_PRINTLN(status);
+    int rssi = -9999;
+    for (int o = 0; o < status; o++) {
+      DEBUG_PRINT(F(" WiFi available: ")); DEBUG_PRINT(WiFi.SSID(o));
+      DEBUG_PRINT(F(" RSSI: ")); DEBUG_PRINT(WiFi.RSSI(o)); DEBUG_PRINTLN(F("dB"));
+      for (unsigned n = 0; n < multiWiFi.size(); n++)
+        if (!strcmp(WiFi.SSID(o).c_str(), multiWiFi[n].clientSSID)) {
+          // find the WiFi with the strongest signal (but keep priority of entry if signal difference is not big)
+          if ((n < selectedWiFi && WiFi.RSSI(o) > rssi-10) || WiFi.RSSI(o) > rssi) {
+            rssi = WiFi.RSSI(o);
+            selectedWiFi = n;
+          }
+          break;
+        }
+    }
+    DEBUG_PRINT(F("Selected: ")); DEBUG_PRINT(multiWiFi[selectedWiFi].clientSSID);
+    DEBUG_PRINT(F(" RSSI: ")); DEBUG_PRINT(rssi); DEBUG_PRINTLN(F("dB"));
+    return true;
+  }
+  //DEBUG_PRINT(F("WiFi scan running."));
+  return false; // scan is still running or there was an error
 }
 
 void WLED::initConnection()
@@ -715,7 +758,7 @@ void WLED::initConnection()
   }
 #endif
 
-  WiFi.disconnect(true);        // close old connections
+  if (findWiFi()) WiFi.disconnect(true); // close old connections (only if scan completed and found networks)
 #ifdef ESP8266
   WiFi.setPhyMode(force802_3g ? WIFI_PHY_MODE_11G : WIFI_PHY_MODE_11N);
 #endif
@@ -752,7 +795,7 @@ void WLED::initConnection()
     // convert the "serverDescription" into a valid DNS hostname (alphanumeric)
     char hostname[25];
     prepareHostname(hostname);
-    WiFi.begin(multiWiFi[selectedWiFi].clientSSID, multiWiFi[selectedWiFi].clientPass);
+    WiFi.begin(multiWiFi[selectedWiFi].clientSSID, multiWiFi[selectedWiFi].clientPass); // no harm if called multiple times
 #ifdef ARDUINO_ARCH_ESP32
   #if defined(LOLIN_WIFI_FIX) && (defined(ARDUINO_ARCH_ESP32C3) || defined(ARDUINO_ARCH_ESP32S2) || defined(ARDUINO_ARCH_ESP32S3))
     WiFi.setTxPower(WIFI_POWER_8_5dBm);
@@ -907,6 +950,7 @@ void WLED::handleConnection()
     if (interfacesInited) {
       DEBUG_PRINTLN(F("Disconnected!"));
       initConnection();
+      findWiFi(true); // reinit scan
       interfacesInited = false;
     }
     //send improv failed 6 seconds after second init attempt (24 sec. after provisioning)
@@ -917,15 +961,15 @@ void WLED::handleConnection()
     if (now - lastReconnectAttempt > ((stac) ? 300000 : 18000) && WLED_WIFI_CONFIGURED) {
       if (improvActive == 2) improvActive = 3;
       DEBUG_PRINTLN(F("Last reconnect too old."));
-      if (++selectedWiFi >= multiWiFi.size()) selectedWiFi = 0;
       initConnection();
+      findWiFi(true); // reinit scan
     }
     if (!apActive && now - lastReconnectAttempt > 12000 && (!wasConnected || apBehavior == AP_BEHAVIOR_NO_CONN)) {
       DEBUG_PRINTLN(F("Not connected AP."));
       initAP();
     }
   } else if (!interfacesInited) { //newly connected
-    DEBUG_PRINTLN("");
+    DEBUG_PRINTLN();
     DEBUG_PRINT(F("Connected! IP address: "));
     DEBUG_PRINTLN(Network.localIP());
     if (improvActive) {

wled00/wled.h

@@ -881,6 +881,7 @@ public:
   void initAP(bool resetAP = false);
   void initConnection();
   void initInterfaces();
+  bool findWiFi(bool doScan = false);
   #if defined(STATUSLED)
   void handleStatusLED();
   #endif