Update HTTPS example

examples/HttpsBuiltlnGet/HttpsBuiltlnGet.ino

@@ -25,12 +25,16 @@ TinyGsm modem(debugger);
 TinyGsm modem(SerialAT);
 #endif
 
-// It depends on the operator whether to set up an APN. If some operators do not set up an APN, 
+// It depends on the operator whether to set up an APN. If some operators do not set up an APN,
 // they will be rejected when registering for the network. You need to ask the local operator for the specific APN.
 // APNs from other operators are welcome to submit PRs for filling.
 // #define NETWORK_APN     "CHN-CT"             //CHN-CT: China Telecom
 
-const char *server_url =  "https://httpbin.org/get";
+const char *request_url[] = {
+    "https://httpbin.org/get",
+    "https://vsh.pp.ua/TinyGSM/logo.txt",
+    "https://ipapi.co/json"
+};
 
 void setup()
 {
@@ -164,30 +168,58 @@ void setup()
     // Initialize HTTPS
     modem.https_begin();
 
-    // Set GET URT
-    if (!modem.https_set_url(server_url)) {
-        Serial.println("Failed to set the URL. Please check the validity of the URL!");
-        return;
-    }
+    // If the status code 715 is returned, please see here
+    // https://github.com/Xinyuan-LilyGO/LilyGO-T-A76XX/issues/117
 
-    // Send GET request
-    int httpCode = 0;
-    httpCode = modem.https_get();
-    if (httpCode != 200) {
-        Serial.print("HTTP get failed ! error code = "); Serial.println(httpCode); return;
-    }
+    for (int i = 0; i < sizeof(request_url) / sizeof(request_url[0]); ++i) {
 
-    // Get HTTPS header information
-    String header = modem.https_header();
-    Serial.print("HTTP Header : ");
-    Serial.println(header);
+        int retry = 3;
 
-    delay(5000);
+        while (retry--) {
+
+            Serial.print("Request URL : ");
+            Serial.println(request_url[i]);
+
+            // Set GET URT
+            if (!modem.https_set_url(request_url[i])) {
+                Serial.print("Failed to request : "); Serial.println(request_url[i]);
+
+                // Debug
+                // modem.sendAT("+CSSLCFG=\"enableSNI\",0,1");
+                // modem.waitResponse();
+                delay(3000);
+                continue;
+            }
+
+            // Send GET request
+            int httpCode = 0;
+            httpCode = modem.https_get();
+            if (httpCode != 200) {
+                Serial.print("HTTP get failed ! error code = ");
+                Serial.println(httpCode);
+                delay(3000);
+                continue;
+            }
+
+            // Get HTTPS header information
+            String header = modem.https_header();
+            Serial.print("HTTP Header : ");
+            Serial.println(header);
 
-    // Get HTTPS response
-    String body = modem.https_body();
-    Serial.print("HTTP body : ");
-    Serial.println(body);
+            delay(1000);
+
+            // Get HTTPS response
+            String body = modem.https_body();
+            Serial.print("HTTP body : ");
+            Serial.println(body);
+
+            delay(3000);
+
+            break;
+        }
+
+        Serial.println("-------------------------------------");
+    }
 }
 
 void loop()