WiFi.begin doesn't connect if connection was already established

[RogerSchaefer]

Installed the new 2.3.0 today and found that a sketch I have used for a long time will no longer cause the ESP8266 to connect with my WiFi

I reverted to version 2.2.0 and the sketch works fine.

ESP8266WiFi was the only ESP8266 include in the sketch

Roger

[igrr]

Will you post your sketch? I can try reproducing that issue.

[hoshinota]

"Millis ()" is strange?
Value of ADC was also been 20 - 30 points lower.

[RogerSchaefer]

Hi igrr,
The code is below; hope it helps.
Roger
///////////////////////////////////////////
// my dashboard
// https://io.adafruit.com/Oldmicroguy/
//
/***************************************************
Adafruit MQTT Library ESP8266 Example

Must use ESP8266 Arduino from:
https://github.com/esp8266/Arduino

Works great with Adafruit's Huzzah ESP board & Feather
----> https://www.adafruit.com/product/2471
----> https://www.adafruit.com/products/2821

Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!

Written by Tony DiCola for Adafruit Industries.
MIT license, all text above must be included in any redistribution
****************************************************/
#include <ESP8266WiFi.h>
#include "Adafruit_MQTT.h"
#include "Adafruit_MQTT_Client.h"
////////////////////////////
// pick one test device //
// //
#define ECOSWITCH 0 //
#define SWEETPEA 0 //
#define NODEMCU 0 //
#define ESP01 1 //
#define THING 0 // Sparkfun Thing
#define SONOFF 0 //
////////////////////////////

#if ESP01 // testing with ESP-01
#define BUTTON_PIN 0
#define LED_PIN 2
#define RELAY 2 // only two outputs on ESP-01
#define INVERT false
#endif

#if THING // testing with Sparkfun THING
#define BUTTON_PIN 0
#define LED_PIN 5
#define RELAY 12
#define INVERT false
#endif

#if SWEETPEA // testing with SweetPea
#define BUTTON_PIN 0
#define LED_PIN BUILTIN_LED
#define RELAY BUILTIN_LED
#define INVERT false
#endif

#if SONOFF // WiFi controlled power relay
#define BUTTON_PIN 0
#define LED_PIN 13
#define RELAY 12
#endif

//#define PULLUP true
//#define INVERT true
//#define DEBOUNCE_MS 100
//#define SINK false

/************************* WiFi Access Point *********************************/

#define WLAN_SSID "T-Mobile Broadband96"
#define WLAN_PASS "xxxxxxx"

/************************* Adafruit.io Setup *********************************/

#define AIO_SERVER "io.adafruit.com"
#define AIO_SERVERPORT 1883 // use 8883 for SSL
#define AIO_USERNAME "Oldmicroguy"
#define AIO_KEY "xxxxxxxxxx"

/************ Global State (you don't need to change this!) ******************/

// Create an ESP8266 WiFiClient class to connect to the MQTT server.
WiFiClient client;
// or... use WiFiFlientSecure for SSL
//WiFiClientSecure client;

// Store the MQTT server, username, and password in flash memory.
// This is required for using the Adafruit MQTT library.
const char MQTT_SERVER[] PROGMEM = AIO_SERVER;
const char MQTT_USERNAME[] PROGMEM = AIO_USERNAME;
const char MQTT_PASSWORD[] PROGMEM = AIO_KEY;

// Setup the MQTT client class by passing in the WiFi client and MQTT server and login details.
Adafruit_MQTT_Client mqtt(&client, MQTT_SERVER, AIO_SERVERPORT, MQTT_USERNAME, MQTT_PASSWORD);

/****************************** Feeds ***************************************/

// Setup a feed called 'photocell' for publishing.
// Notice MQTT paths for AIO follow the form: /feeds/

const char PHOTOCELL_FEED[] PROGMEM = AIO_USERNAME "/feeds/photocell";
Adafruit_MQTT_Subscribe photocell = Adafruit_MQTT_Subscribe(&mqtt, PHOTOCELL_FEED);

// Setup a feed called 'onoff' for subscribing to changes.
const char ONOFF_FEED[] PROGMEM = AIO_USERNAME "/feeds/onoffbutton";
Adafruit_MQTT_Subscribe onoffbutton = Adafruit_MQTT_Subscribe(&mqtt, ONOFF_FEED);

/*************************** Sketch Code ************************************/

// Bug workaround for Arduino 1.6.6, it seems to need a function declaration
// for some reason (only affects ESP8266, likely an arduino-builder bug).
//void MQTT_connect();

void setup() {
Serial.begin(9600);
delay(10);
pinMode(LED_PIN, OUTPUT); // Initialize the BUILTIN_LED pin as an output
pinMode(RELAY,OUTPUT);
digitalWrite(RELAY, LOW);
blink(5);
digitalWrite(LED_PIN, LOW);
Serial.println();
Serial.println(F("Adafruit MQTT demo"));

// Connect to WiFi access point.
Serial.println(); Serial.println();
Serial.print("Connecting to ");
Serial.println(WLAN_SSID);

WiFi.begin(WLAN_SSID, WLAN_PASS);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println();

Serial.println("WiFi connected");
Serial.println("IP address: "); Serial.println(WiFi.localIP());

// Setup MQTT subscription for onoff feed.
mqtt.subscribe(&onoffbutton);
mqtt.subscribe(&photocell);
}
////////// End of Setup ///////////////////
///////////////////////////////////////////
uint32_t x=0;

void loop() {
// Ensure the connection to the MQTT server is alive (this will make the first
// connection and automatically reconnect when disconnected). See the MQTT_connect
// function definition further below.
MQTT_connect();

// this is our 'wait for incoming subscription packets' busy subloop
// try to spend your time here

Adafruit_MQTT_Subscribe *subscription;
while ((subscription = mqtt.readSubscription(1000))) {
// Check if its the onoff button feed
if (subscription == &onoffbutton) {
Serial.print(F("On-Off button: "));
Serial.println((char *)onoffbutton.lastread);

  if (strcmp((char *)onoffbutton.lastread, "ON") == 0) {
    digitalWrite(LED_PIN, LOW); 
  }
  if (strcmp((char *)onoffbutton.lastread, "OFF") == 0) {
    digitalWrite(LED_PIN, HIGH); 
  }
}
if (subscription == &photocell) {
  //Serial.print(F("Value "));
  //Serial.println((char *)photocell.lastread);
  Serial.print(F("Temperature "));
  float temp = atof((char *)photocell.lastread);
  Serial.print(temp, 1);
  Serial.println(" F");
  if (temp < 69.0) {
    if (INVERT) digitalWrite(LED_PIN, HIGH); else digitalWrite(LED_PIN,LOW);
    if (INVERT) digitalWrite(RELAY, HIGH); else digitalWrite(RELAY, LOW);
  }
  if (temp > 70.0) {
    if (INVERT) digitalWrite(LED_PIN, LOW); else digitalWrite(LED_PIN,HIGH);
    if (INVERT) digitalWrite(RELAY, LOW); else digitalWrite(RELAY, HIGH);
  }
}

}
// Now we can publish stuff!
/*
Serial.print(F("\nSending photocell val "));
Serial.print(x);
Serial.print("...");
if (! photocell.publish(x++)) {
Serial.println(F("Failed"));
} else {
Serial.println(F("OK!"));
}*/
// ping the server to keep the mqtt connection alive
// NOT required if you are publishing once every KEEPALIVE seconds

if(! mqtt.ping()) {
mqtt.disconnect();
}
}
//////// End of Loop //////////////////
//////////////////////////////////////

// Function to connect and reconnect as necessary to the MQTT server.
// Should be called in the loop function and it will take care if connecting.
void MQTT_connect() {
int8_t ret;

// Stop if already connected.
if (mqtt.connected()) {
return;
}

Serial.print("Connecting to MQTT... ");

uint8_t retries = 3;
while ((ret = mqtt.connect()) != 0) { // connect will return 0 for connected
Serial.println(mqtt.connectErrorString(ret));
Serial.println("Retrying MQTT connection in 5 seconds...");
mqtt.disconnect();
delay(5000); // wait 5 seconds
retries--;
if (retries == 0) {
// basically die and wait for WDT to reset me
while (1);
}
}
Serial.println("MQTT Connected!");
}
///////////////////////////////
void blink (int i) {
while (i) {
digitalWrite(LED_PIN, LOW); // Turn the LED on (Note that LOW is the voltage level
// but actually the LED is on)
delay(250); // Wait a bit
digitalWrite(LED_PIN, HIGH); // Turn the LED off by making the voltage HIGH
delay(250);
i--;
}
}
///////////////////////////////

[zfields]

I am using the AzureIoTHub simplesample_http. It works perfectly with 2.2, but upon grading to 2.3 I get this experience. I can connect to my router (reports assigned an IP address), but it keeps looping as though it failed and spews cryptic debugging errors.

[mkeyno]

I have same problem with it , my connection get lost sometimes but module try to reconnect to Access point , and this make me problem when using the websocket

[igrr]

@RogerSchaefer
I have loaded the provided sketch, changed SSID and password and connection went fine.
Could you please provide serial output when debugging is enabled?
Please set "Debug Port: Serial" and "Debug Level: Core" in Arduino Tools menu, and add Serial.setDebugOutput(true); line after Serial.begin(9600);. This will print some info from WiFi stack.
We had an SDK update between 2.2.0 and 2.3.0. Because SDK updates sometimes don't migrate parameter storage area in flash correctly, this can cause connection issues. Debug output can give more hints at what's happening on your side.

@zfields since this is a third party library, best we can do is help you make sense of "cryptic debugging errors" (whatever that may mean). Please feel free to open an issue, and provide the exact sketch you are running, settings you have in IDE tools menu, and full serial output. Thanks.

[RogerSchaefer]

Hello @igrr
I have attached debug files from both Ver 2.2.0 and Ver 2.3.0
The object of the sketch is to get mqtt temperature data.
Ver 2.2.0 connects quickly
Ver 2.3.0 sometimes after 10 or 20 minutes

Roger

sonoff_mqtt Ver 2.3.0.txt
sonoff_mqtt Ver 2.2.0.txt

[igrr]

Thanks for the logs, I was able to reproduce this with 2.3.0.

Apparently, with SDK 1.5.3, if you call WiFi.begin by the time WiFi connection is already established, WiFi connection state machine enters some weird state. SDK function wifi_station_get_connect_status keeps returning STATION_CONNECTING, even though the connection is in fact established.

This was resolved in SDK 1.5.4, which is available in current git version of ESP8266 core.
I tested the same code with git version and it worked fine.

As a workaround, you can replace WiFi.begin(ssid, password); with

if (WiFi.status() != WL_CONNECTED) {
  WiFi.begin(ssid, password);
}

or with

WiFi.persistent(false);
WiFi.mode(WIFI_OFF);   // this is a temporary line, to be removed after SDK update to 1.5.4
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);

I will consider releasing 2.3.1 with a workaround for this issue in a couple of days.