Update WiFiScan example to show more useful data (espressif#7378)

* Update `WiFiScan` example to show more useful data

* Add channel to output.
* Add type of encryption to output.
* Format output as table.
* Update outdated example description.
* Add `scanDelete()` as hint to free memory.

* added 32 chars SSID + readme edit

Co-authored-by: Jan Procházka <90197375+P-R-O-C-H-Y@users.noreply.github.com>

Author: Rotzbua

libraries/WiFi/examples/WiFiScan/README.md

@@ -2,12 +2,12 @@
 
 This example demonstrates how to use the WiFi library to scan available WiFi networks and print the results.
 
-# Supported Targets
+## Supported Targets
 
 Currently this example supports the following targets.
 
-| Supported Targets | ESP32 | ESP32-S2 | ESP32-C3 |
-| ----------------- | ----- | -------- | -------- |
+| Supported Targets | ESP32 | ESP32-S2 | ESP32-C3 | ESP32-S3 |
+| ----------------- | ----- | -------- | -------- | -------- |
 
 ## How to Use Example
 
@@ -25,25 +25,16 @@ Currently this example supports the following targets.
 ## Example/Log Output
 
 ```
-ets Jul 29 2019 12:21:46
-
-rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
-configsip: 0, SPIWP:0xee
-clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
-mode:DIO, clock div:1
-load:0x3fff0030,len:1412
-load:0x40078000,len:13400
-load:0x40080400,len:3672
-entry 0x400805f8
 Setup done
-scan start
-scan done
+Scan start
+Scan done
 17 networks found
-1: IoTNetwork (-62)*
-2: WiFiSSID (-62)*
-3: B3A7992 (-63)*
-4: WiFi (-63) 
-5: IoTNetwork2 (-64)*
+Nr | SSID            | RSSI | CH | Encryption
+ 1 | IoTNetwork      |  -62 |  1 | WPA2
+ 2 | WiFiSSID        |  -62 |  1 | WPA2-EAP
+ 3 | B3A7992         |  -63 |  6 | WPA+WPA2
+ 4 | WiFi            |  -63 |  6 | WPA3
+ 5 | IoTNetwork2     |  -64 | 11 | WPA2+WPA3
 ...
 ```
 

libraries/WiFi/examples/WiFiScan/WiFiScan.ino

@@ -1,15 +1,15 @@
 /*
  *  This sketch demonstrates how to scan WiFi networks.
- *  The API is almost the same as with the WiFi Shield library,
- *  the most obvious difference being the different file you need to include:
+ *  The API is based on the Arduino WiFi Shield library, but has significant changes as newer WiFi functions are supported.
+ *  E.g. the return value of `encryptionType()` different because more modern encryption is supported.
  */
 #include "WiFi.h"
 
 void setup()
 {
     Serial.begin(115200);
 
-    // Set WiFi to station mode and disconnect from an AP if it was previously connected
+    // Set WiFi to station mode and disconnect from an AP if it was previously connected.
     WiFi.mode(WIFI_STA);
     WiFi.disconnect();
     delay(100);
@@ -19,30 +19,68 @@ void setup()
 
 void loop()
 {
-    Serial.println("scan start");
+    Serial.println("Scan start");
 
-    // WiFi.scanNetworks will return the number of networks found
+    // WiFi.scanNetworks will return the number of networks found.
     int n = WiFi.scanNetworks();
-    Serial.println("scan done");
+    Serial.println("Scan done");
     if (n == 0) {
         Serial.println("no networks found");
     } else {
         Serial.print(n);
         Serial.println(" networks found");
+        Serial.println("Nr | SSID                             | RSSI | CH | Encryption");
         for (int i = 0; i < n; ++i) {
             // Print SSID and RSSI for each network found
-            Serial.print(i + 1);
-            Serial.print(": ");
-            Serial.print(WiFi.SSID(i));
-            Serial.print(" (");
-            Serial.print(WiFi.RSSI(i));
-            Serial.print(")");
-            Serial.println((WiFi.encryptionType(i) == WIFI_AUTH_OPEN)?" ":"*");
+            Serial.printf("%2d",i + 1);
+            Serial.print(" | ");
+            Serial.printf("%-32.32s", WiFi.SSID(i).c_str());
+            Serial.print(" | ");
+            Serial.printf("%4d", WiFi.RSSI(i));
+            Serial.print(" | ");
+            Serial.printf("%2d", WiFi.channel(i));
+            Serial.print(" | ");
+            switch (WiFi.encryptionType(i))
+            {
+            case WIFI_AUTH_OPEN:
+                Serial.print("open");
+                break;
+            case WIFI_AUTH_WEP:
+                Serial.print("WEP");
+                break;
+            case WIFI_AUTH_WPA_PSK:
+                Serial.print("WPA");
+                break;
+            case WIFI_AUTH_WPA2_PSK:
+                Serial.print("WPA2");
+                break;
+            case WIFI_AUTH_WPA_WPA2_PSK:
+                Serial.print("WPA+WPA2");
+                break;
+            case WIFI_AUTH_WPA2_ENTERPRISE:
+                Serial.print("WPA2-EAP");
+                break;
+            case WIFI_AUTH_WPA3_PSK:
+                Serial.print("WPA3");
+                break;
+            case WIFI_AUTH_WPA2_WPA3_PSK:
+                Serial.print("WPA2+WPA3");
+                break;
+            case WIFI_AUTH_WAPI_PSK:
+                Serial.print("WAPI");
+                break;
+            default:
+                Serial.print("unknown");
+            }
+            Serial.println();
             delay(10);
         }
     }
     Serial.println("");
 
-    // Wait a bit before scanning again
+    // Delete the scan result to free memory for code below.
+    WiFi.scanDelete();
+
+    // Wait a bit before scanning again.
     delay(5000);
 }