Add timeout to STA::waitForConnectResult (#5371)

Author: dav1901

doc/esp8266wifi/station-class.rst

@@ -254,6 +254,7 @@ Function returns one of the following connection statuses:
 - ``WL_CONNECT_FAILED`` if password is incorrect 
 - ``WL_IDLE_STATUS`` when Wi-Fi is in process of changing between statuses 
 - ``WL_DISCONNECTED`` if module is not configured in station mode
+- ``-1`` on timeout
 
 Configuration
 ~~~~~~~~~~~~~

libraries/ESP8266AVRISP/examples/Arduino_Wifi_AVRISP/Arduino_Wifi_AVRISP.ino

@@ -24,7 +24,10 @@ void setup() {
 
   WiFi.mode(WIFI_STA);
   WiFi.begin(ssid, pass);
-  while (WiFi.waitForConnectResult() != WL_CONNECTED);
+  while (WiFi.waitForConnectResult() != WL_CONNECTED) {
+    WiFi.begin(ssid, pass);
+    Serial.println("WiFi failed, retrying.");
+  }
 
   MDNS.begin(host);
   MDNS.addService("avrisp", "tcp", port);

libraries/ESP8266WiFi/src/ESP8266WiFiSTA.cpp

@@ -25,6 +25,7 @@
 #include "ESP8266WiFi.h"
 #include "ESP8266WiFiGeneric.h"
 #include "ESP8266WiFiSTA.h"
+#include "PolledTimeout.h"
 
 #include "c_types.h"
 #include "ets_sys.h"
@@ -441,17 +442,22 @@ bool ESP8266WiFiSTAClass::getAutoReconnect() {
 /**
  * Wait for WiFi connection to reach a result
  * returns the status reached or disconnect if STA is off
- * @return wl_status_t
+ * @return wl_status_t or -1 on timeout
  */
-uint8_t ESP8266WiFiSTAClass::waitForConnectResult() {
+int8_t ESP8266WiFiSTAClass::waitForConnectResult(unsigned long timeoutLength) {
     //1 and 3 have STA enabled
     if((wifi_get_opmode() & 1) == 0) {
         return WL_DISCONNECTED;
     }
-    while(status() == WL_DISCONNECTED) {
-        delay(100);
+    using esp8266::polledTimeout::oneShot;
+    oneShot timeout(timeoutLength); // number of milliseconds to wait before returning timeout error
+    while(!timeout) {
+        yield();
+        if(status() != WL_DISCONNECTED) {
+            return status();
+        }
     }
-    return status();
+    return -1; // -1 indicates timeout
 }
 
 /**

libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h

@@ -57,7 +57,7 @@ class ESP8266WiFiSTAClass {
         bool setAutoReconnect(bool autoReconnect);
         bool getAutoReconnect();
 
-        uint8_t waitForConnectResult();
+        int8_t waitForConnectResult(unsigned long timeoutLength = 60000);
 
         // STA network info
         IPAddress localIP();