Can't initiate WiFi network connection in BLE Blynk app

Solved
1

Here’s my setup.

  • I’ve got Blynk running on an M5Stack - works great.
  • The connection between my phone and the M5Stack is via BLE - works great.
  • I have a Toshiba FlashAir card in my DSLR camera. I’m trying to initiate a WiFi connection from the Arduino Blynk board to the FlashAir card to pull data and execute scripts.
  • In isolation (a non-Blynk sketch) this works like a champ. Inside a Blynk sketch, no dice.

The WiFi.h here refers to ESP8266WiFi.h.

Here’s my isolated test code (sourced from other people’s examples) that works without Blynk:

#include <ArduinoHttpClient.h>
#include <WiFi.h>
#include <M5Stack.h>
#include "FileHelpers.h"

char ssid []= "flashair_001";
char pass [] = "12345678";

const char* host = "192.168.0.1";

// Use WiFiClient class to create TCP connections
WiFiClient wifi;
HttpClient client = HttpClient(wifi, host, 80);
int status = WL_IDLE_STATUS;
String response;
int statusCode = 0;

void setup()
{
	M5.begin(); //specific init for this board. 
	M5.Lcd.setBrightness(200);
	Serial.begin(115200);
	delay(10);

	listNetworks();

	while (status != WL_CONNECTED) {
		Serial.print(status + " : Attempting to connect to Network named: ");
		Serial.println(ssid);                   // print the network name (SSID);

		// Connect to WPA/WPA2 network:
		delay(1000);
		status = WiFi.begin(ssid, pass);

	}

	Serial.println("Connected!");

}

void loop()
{
}

void listNetworks() {
	// scan for nearby networks:
	Serial.println("** Scan Networks **");
	int numSsid = WiFi.scanNetworks();
	if (numSsid == -1) {
		Serial.println("Couldn't get a wifi connection");
		while (true);
	}

	// print the list of networks seen:
	Serial.print("number of available networks:");
	Serial.println(numSsid);

	// print the network number and name for each network found:
	for (int thisNet = 0; thisNet < numSsid; thisNet++) {
		Serial.print(thisNet);
		Serial.print(") ");
		Serial.print(WiFi.SSID(thisNet));
	}
}

That routine connects to the FlashAir wifi network just fine and I get to “Connected” without a problem.

Here are the relevant parts of my sketch with Blynk, where I never manage to get to status == WL_Connected:

#include <BlynkSimpleEsp32_BLE.h>
#include <BLEDevice.h>
#include <BLEServer.h>
#include <ETH.h>
#include <M5Stack.h>
#include <ArduinoHttpClient.h>
#include <WiFi.h>

//a bunch of blah blah blah and other irrelevant code

char ssid[] = "flashair_001";
char pass[] = "12345678";

void setup()
{
	Serial.begin(115200);
	Blynk.begin(auth);
	M5.begin();
	ConnectToFlashAir();
}

void ConnectToFlashAir() {

	//WiFi.disconnect();

	listNetworks();
	
	status = WiFi.begin(ssid, pass);
	BlynkDelay(500);
	while (status != WL_CONNECTED) {
		Serial.print(String(status) + " : Attempting to connect to Network named: ");
		Serial.println(ssid);                   // print the network name (SSID);
		// Connect to WPA/WPA2 network:
		BlynkDelay(500);
		status = WiFi.begin(ssid, pass);
	}
        Serial.println("Connected!")
}

The output is:

** Scan Networks **
E (1617) wifi: esp_wifi_scan_start 967 wifi not start
number of available networks:-2
6 : Attempting to connect to Network named: flashair_001
6 : Attempting to connect to Network named: flashair_001
…and so on.

The value of 6 corresponds to status WL_DISCONNECTED.

Interestingly, if I uncomment WiFi.disconnect() at the beginning (recommended on another thread, I get the following behavior:

** Scan Networks **
number of available networks:2
0) flashair_001 Signal: -16 dBm 1) CGNVM-ADD0 Signal: -57 dBm
6 : Attempting to connect to Network named: flashair_001
6 : Attempting to connect to Network named: flashair_001
6 : Attempting to connect to Network named: flashair_001
…and on and on for ever.

So a little closer, but still no connection.

I can tell that the hardware can see the WiFi network. I know that the password is correct. My other devices can connect just fine, including the very same hardware loaded with my isolated test sketch.It seems like somehow including the Blynk libraries is conflicting with the way WiFi should function.

Any ideas of the root cause, a workaround, or more steps to take to debug?

Thanks in advance, awesome Blynk community!

2

Post your full code for the Blynk sketch and we might be able to se what the problem. Snippets of code don’t give enough information.

Pete.

3

Turns out that the root issue is memory management. In my project, I have a few very large arrays and it seems like their existence is interfering with the WiFi class’s ability to successfully complete its operations. If I reduce the size of those arrays, everything works as it should - Blynk and all!

I’m going to move from big arrays to a flat file database on my SD card.

This is what I get for learning to program in languages like C# and Java. I’ve never had to give much thought to memory management, and it’s currently biting me in the behind :slight_smile:

Marking as solved.