add WiFi scan Async mode

libraries/ESP8266WiFi/src/ESP8266WiFi.cpp

@@ -40,7 +40,9 @@ extern "C" void esp_schedule();
 extern "C" void esp_yield();
 
 ESP8266WiFiClass::ESP8266WiFiClass()
-: _useApMode(false)
+: _smartConfigStarted(false)
+, _smartConfigDone(false)
+, _useApMode(false)
 , _useClientMode(false)
 , _useStaticIp(false)
 {
@@ -121,7 +123,7 @@ uint8_t ESP8266WiFiClass::waitForConnectResult(){
 }
 
 
-// You will have to set the DNS-Server manually later since this will not enable DHCP
+// You will have to set the DNS-Server manually later since this will not enable DHCP2
 void ESP8266WiFiClass::config(IPAddress local_ip, IPAddress gateway, IPAddress subnet)
 {
     struct ip_info info;
@@ -357,12 +359,47 @@ void ESP8266WiFiClass::_scanDone(void* result, int status)
         }
 
     }
+
+    ESP8266WiFiClass::_scanStarted = false;
+    ESP8266WiFiClass::_scanComplete = true;
+
+    if(!ESP8266WiFiClass::_scanAsync) {
         esp_schedule();
+    }
 }
 
+int8_t ESP8266WiFiClass::scanComplete() {
 
-int8_t ESP8266WiFiClass::scanNetworks()
+    if(_scanStarted) {
+        return WIFI_SCAN_RUNNING;
+    }
+
+    if(_scanComplete) {
+        return ESP8266WiFiClass::_scanCount;
+    }
+
+    return WIFI_SCAN_FAILD;
+}
+
+void ESP8266WiFiClass::scanDelete()
 {
+    if (ESP8266WiFiClass::_scanResult)
+    {
+        delete[] reinterpret_cast<bss_info*>(ESP8266WiFiClass::_scanResult);
+        ESP8266WiFiClass::_scanResult = 0;
+        ESP8266WiFiClass::_scanCount = 0;
+    }
+    _scanComplete = false;
+}
+
+int8_t ESP8266WiFiClass::scanNetworks(bool async)
+{
+    if(ESP8266WiFiClass::_scanStarted) {
+        return WIFI_SCAN_RUNNING;
+    }
+
+    ESP8266WiFiClass::_scanAsync = async;
+
     if(_useApMode) {
         // turn on AP+STA mode
         mode(WIFI_AP_STA);
@@ -377,21 +414,28 @@ int8_t ESP8266WiFiClass::scanNetworks()
         disconnect();
     }
     
-    if (ESP8266WiFiClass::_scanResult)
+    scanDelete();
-    {
-        delete[] reinterpret_cast<bss_info*>(ESP8266WiFiClass::_scanResult);
-        ESP8266WiFiClass::_scanResult = 0;
-        ESP8266WiFiClass::_scanCount = 0;
-    }
 
     struct scan_config config;
     config.ssid = 0;
     config.bssid = 0;
     config.channel = 0;
     config.show_hidden = 0;
-    wifi_station_scan(&config, reinterpret_cast<scan_done_cb_t>(&ESP8266WiFiClass::_scanDone));
+    if(wifi_station_scan(&config, reinterpret_cast<scan_done_cb_t>(&ESP8266WiFiClass::_scanDone))) {
+        ESP8266WiFiClass::_scanComplete = false;
+        ESP8266WiFiClass::_scanStarted = true;
+
+        if(ESP8266WiFiClass::_scanAsync) {
+            delay(0); // time for the OS to trigger the scan
+            return WIFI_SCAN_RUNNING;
+        }
+
         esp_yield();
         return ESP8266WiFiClass::_scanCount;
+    } else {
+        return WIFI_SCAN_FAILD;
+    }
+
 }
 
 void * ESP8266WiFiClass::_getScanInfoByIndex(int i)
@@ -644,6 +688,10 @@ void ESP8266WiFiClass::printDiag(Print& p)
 
 }
 
+bool ESP8266WiFiClass::_scanAsync = false;
+bool ESP8266WiFiClass::_scanStarted = false;
+bool ESP8266WiFiClass::_scanComplete = false;
+
 size_t ESP8266WiFiClass::_scanCount = 0;
 void* ESP8266WiFiClass::_scanResult = 0;
 

libraries/ESP8266WiFi/src/ESP8266WiFi.h

@@ -32,6 +32,9 @@ extern "C" {
 #include "WiFiClient.h"
 #include "WiFiServer.h"
 
+#define WIFI_SCAN_RUNNING   (-1)
+#define WIFI_SCAN_FAILD     (-2)
+
 enum WiFiMode { WIFI_OFF = 0, WIFI_STA = 1, WIFI_AP = 2, WIFI_AP_STA = 3 };
 
 class ESP8266WiFiClass
@@ -189,12 +192,26 @@ public:
 
     int32_t RSSI();
 
+
+    /*
+     * called to get the scan state in Async mode
+     *
+     * return -1 if scan not fin
+     * return -2 if scan not triggered
+     */
+    int8_t scanComplete();
+
+    /*
+     * delete last scan result from RAM
+     */
+    void scanDelete();
+
     /*
      * Start scan WiFi networks available
      *
      * return: Number of discovered networks
      */
-    int8_t scanNetworks();
+    int8_t scanNetworks(bool async = false);
 
     /*
      * Return the SSID discovered during the network scan.
@@ -314,13 +331,17 @@ protected:
     void * _getScanInfoByIndex(int i);
     static void _smartConfigCallback(uint32_t status, void* result);
     static void _eventCallback(void *event);
-    bool _smartConfigStarted = false;
+    bool _smartConfigStarted;
-    bool _smartConfigDone = false;
+    bool _smartConfigDone;
 
     bool _useApMode;
     bool _useClientMode;
 	bool _useStaticIp;
 	
+	static bool _scanAsync;
+	static bool _scanStarted;
+	static bool _scanComplete;
+
     static size_t _scanCount;
     static void* _scanResult;
 

libraries/ESP8266WiFi/src/ESP8266WiFiMulti.cpp

@@ -40,29 +40,29 @@ bool ESP8266WiFiMulti::addAP(const char* ssid, const char *passphrase) {
 
 wl_status_t ESP8266WiFiMulti::run(void) {
 
+    int8_t scanResult;
     wl_status_t status = WiFi.status();
     if(status == WL_DISCONNECTED || status == WL_NO_SSID_AVAIL || status == WL_IDLE_STATUS || status == WL_CONNECT_FAILED) {
 
+        scanResult = WiFi.scanComplete();
+        if(scanResult == WIFI_SCAN_RUNNING) {
+            // scan is running
+            return WL_NO_SSID_AVAIL;
+        } else if(scanResult > 0) {
+            // scan done analyze
             WifiAPlist_t bestNetwork { NULL, NULL };
             int bestNetworkDb = INT_MIN;
             uint8 bestBSSID[6];
             int32_t bestChannel;
 
-        DEBUG_WIFI_MULTI("[WIFI] delete old wifi config...\n");
-        WiFi.disconnect();
-
-        DEBUG_WIFI_MULTI("[WIFI] start scan\n");
-        // WiFi.scanNetworks will return the number of networks found
-        int8_t n = WiFi.scanNetworks();
-
             DEBUG_WIFI_MULTI("[WIFI] scan done\n");
             delay(0);
 
-        if(n <= 0) {
+            if(scanResult <= 0) {
                 DEBUG_WIFI_MULTI("[WIFI] no networks found\n");
             } else {
-            DEBUG_WIFI_MULTI("[WIFI] %d networks found\n", n);
+                DEBUG_WIFI_MULTI("[WIFI] %d networks found\n", scanResult);
-            for(int8_t i = 0; i < n; ++i) {
+                for(int8_t i = 0; i < scanResult; ++i) {
 
                     String ssid_scan;
                     int32_t rssi_scan;
@@ -102,6 +102,9 @@ wl_status_t ESP8266WiFiMulti::run(void) {
                 }
             }
 
+            // clean up ram
+            WiFi.scanDelete();
+
             DEBUG_WIFI_MULTI("\n\n");
             delay(0);
 
@@ -142,6 +145,15 @@ wl_status_t ESP8266WiFiMulti::run(void) {
             } else {
                 DEBUG_WIFI_MULTI("[WIFI] no matching wifi found!\n");
             }
+        } else {
+            // start scan
+            DEBUG_WIFI_MULTI("[WIFI] delete old wifi config...\n");
+            WiFi.disconnect();
+
+            DEBUG_WIFI_MULTI("[WIFI] start scan\n");
+            // scan wifi async mode
+            WiFi.scanNetworks(true);
+        }
     }
     return status;
 }