WiFi.scanNetworks() does not work with last version of repository

[mikey60]

Hardware:

Board: ESP32 Dev Module
Core Installation/update date: Clean install on Windows 10 - October 21 2017
IDE name: Arduino IDE
Flash Frequency: 40 and 80Mhz tried
Upload Speed: 921600?

Description:

After doing a clean install of the the latest arduino-esp32 the WiFi.scanNetworks() function does not work any more in my program so I tried the ESP32 WiFIScan.ino example and the serial monitor reports:

scan start
scan done
no networks found

It worked correctly in an earlier version of arduino-esp32 (version of approximately 2 weeks ago)

Sketch:

WiFIScan.ino

/*
 *  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:
 */
#include "WiFi.h"

void setup()
{
    Serial.begin(115200);

    // Set WiFi to station mode and disconnect from an AP if it was previously connected
    WiFi.mode(WIFI_STA);
    WiFi.disconnect();
    delay(100);

    Serial.println("Setup done");
}

void loop()
{
    Serial.println("scan start");

    // WiFi.scanNetworks will return the number of networks found
    int n = WiFi.scanNetworks();
    Serial.println("scan done");
    if (n == 0) {
        Serial.println("no networks found");
    } else {
        Serial.print(n);
        Serial.println(" networks found");
        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)?" ":"*");
            delay(10);
        }
    }
    Serial.println("");

    // Wait a bit before scanning again
    delay(5000);
}

Debug Messages:

[D][WiFiGeneric.cpp:265] _eventCallback(): Event: 1 - SCAN_DONE

[derpicknicker1]

This is a known bug. See #242
There you will find a workaround.

[mikey60]

Thank you for the tip. I added the two following lines of code before the WiFi.scanNetworks() function as suggested at the end of #242 and it worked.

    WiFi.disconnect();
    WiFi.begin("lolllool","loooooooool"); //Can be a nonexistent network