Connection keeps droping when ESP8266 set up as an access point

[vitorsilvalima]

Hi guys, I have been facing some issues when I program my ESP8266/NODEMCU board as an access point. I'm currently using the Arduino version 1.6.7 and esp8266 version 2.0.0. I have tested with different sketches of mine and even with the one provided as an example(WiFIAccessPoint). I don't know why but the connection is really loose and the phone takes a long time to be able to connect to it. I have used ping tools to test sending data to the board and there is a lot of packet loss and connection timeout. The board sometimes even restarts with no reason.
What is the most interesting is that when I use esp8266 version 1.6.5 there seems to have no issues and the connection never times out.
ps: I use Fedora 23 64 bits.

[vitorsilvalima]

I have installed Arduino version 1.6.5 just to make sure there wasn't any conflict with the IDE and I still have the same issues

[hallard]

@vitorsilvalima
I've got the same issue and I found how to reproduce it, I think there is a problem somewhere in the SDK, I spend some time to figure out the problem, here are the step to reproduce this issue :

• Burn a sketch that use STA+AP to connect to your local Wifi with SSID/Password AND also provide AP (this will also initialize some SDK params). In this case AP is working fine
• then burn the same sketch back changing your local wifi SSID (the one to connect to your router/ap line WiFi.begin("YOUR-AP", "YourPSK")) with wrong value so it won't be able to connect to your Wifi. In this case SoftAP is slow and unusable, look at ping

Request timeout for icmp_seq 4181
Request timeout for icmp_seq 4182
64 bytes from 192.168.4.1: icmp_seq=4183 ttl=255 time=5.497 ms
Request timeout for icmp_seq 4184
Request timeout for icmp_seq 4185
Request timeout for icmp_seq 4186
Request timeout for icmp_seq 4187
64 bytes from 192.168.4.1: icmp_seq=4188 ttl=255 time=46.786 ms
64 bytes from 192.168.4.1: icmp_seq=4189 ttl=255 time=34.177 ms
Request timeout for icmp_seq 4190
Request timeout for icmp_seq 4191
Request timeout for icmp_seq 4192
Request timeout for icmp_seq 4193
Request timeout for icmp_seq 4194
64 bytes from 192.168.4.1: icmp_seq=4195 ttl=255 time=31.984 ms
Request timeout for icmp_seq 4196
64 bytes from 192.168.4.1: icmp_seq=4196 ttl=255 time=1740.184 ms
64 bytes from 192.168.4.1: icmp_seq=4198 ttl=255 time=108.993 ms
64 bytes from 192.168.4.1: icmp_seq=4199 ttl=255 time=22.304 ms
64 bytes from 192.168.4.1: icmp_seq=4200 ttl=255 time=3.922 ms
Request timeout for icmp_seq 4201
64 bytes from 192.168.4.1: icmp_seq=4202 ttl=255 time=8.549 ms
64 bytes from 192.168.4.1: icmp_seq=4203 ttl=255 time=26.428 ms
Request timeout for icmp_seq 4204

here a testing sketch to see the issue

#include <ESP8266WiFi.h>
#include <WiFiClient.h> 
#include <ESP8266WebServer.h>
#define SERIAL_DEBUG    Serial
ESP8266WebServer server(80);
void handleRoot() {
    server.send(200, "text/html", "<h1>Hello World!</h1>");
}

void setup() {
    int ret;
  // Set WiFi to station mode and disconnect from an AP if it was previously connected
  WiFi.mode(WIFI_AP_STA);
  SERIAL_DEBUG.begin(115200);
  SERIAL_DEBUG.println("\r\n========== SDK Saved parameters Start"); 
  WiFi.printDiag(SERIAL_DEBUG);
  SERIAL_DEBUG.println("========== SDK Saved parameters End"); 

  SERIAL_DEBUG.println("Connecting...");
  SERIAL_DEBUG.flush();

  WiFi.begin("YOUR-AP", "YourPSK");

  uint8_t timeout = 20; // 20 * 500 ms = 5 sec time out
  while ( ((ret = WiFi.status()) != WL_CONNECTED) && timeout ){
    SERIAL_DEBUG.print(".");
    SERIAL_DEBUG.flush();
    delay(500);
    --timeout;
  }

  // connected ? 
  if ((ret = WiFi.status()) == WL_CONNECTED) {
    SERIAL_DEBUG.println("connected!");

    SERIAL_DEBUG.print("IP address   : "); 
    SERIAL_DEBUG.println(WiFi.localIP());
    SERIAL_DEBUG.print("MAC address  : "); 
    SERIAL_DEBUG.println(WiFi.macAddress());

  // not connected ? start AP
  } else {
    SERIAL_DEBUG.println("Configuring access point...");
    SERIAL_DEBUG.flush();
    WiFi.softAP("ESP-SOFTAP","allowme");
    SERIAL_DEBUG.print("WiFi.softAP() called");
    SERIAL_DEBUG.flush();
    WiFi.softAPIP();

    SERIAL_DEBUG.print("IP address   : "); 
    SERIAL_DEBUG.println(WiFi.softAPIP());
    SERIAL_DEBUG.print("MAC address  : "); 
    SERIAL_DEBUG.println(WiFi.softAPmacAddress());
  }

    server.on("/", handleRoot);
    server.begin();
    SERIAL_DEBUG.println("HTTP server started");
}

void loop() {
    server.handleClient();
}

[hallard]

Oh, sorry, forgot to mention doing an ESP.eraseConfig() at the beginning os setup()does not solve the problem.
May be disabling auto connect could help (I need to try tomorrow) but we'll loose a major feature, auto reconnect is case of main Router/AP reboot

[hallard]

Ok, I've done some basic investigations, hoping some SDK's guru will be able to help us to understand.

I've done a sketch that switch Wifi autoConnect parameter back and forth using NodeMCU board flash button, pushing button toggle on and off. But as changing autoConnect in loop does nothing (SDK says) so on each change I reboot the board.
What is clear is that if autoConnect is on and and Wifi STA SSID/PSK does not connect or Router not present, the problem occurs in AP mode (may be take too much time trying to connect in STA mode)
And, as soon as autoConnect is disable, AP is working fine, so I suspect autoConnect routine.

But there is a 2nd point, all I've just written is true only if you call ESP.eraseConfig() at the beginning of setup(). If you don't do that, AP is slow and broken whatever autoConnect is on or off. This means that SDK is storing something else somewhere used in conjunction with autoConnect.

Note also that ESP.eraseConfig() preserve autoConnect flag ;-)

Here is the sktech used

#include <ESP8266WiFi.h>
#include <WiFiClient.h> 
#include <ESP8266WebServer.h>

#define SERIAL_DEBUG  Serial

bool autoConnect;
int buttonState;            
int lastButtonState = LOW;  
long lastDebounceTime = 0;  
long debounceDelay = 50;    // the debounce time

/* ======================================================================
Function: handle_key_led 
Purpose : Manage on board Led and Push button of NodeMCU boards
Input   : 1 to light on the led, 0 to light off
Output  : 1 if button is pressed
Comments: on NodeMCU led is GPIO16 and switch (Flash) on GPIO 0
====================================================================== */
uint8_t handle_key_led( uint8_t level)
{
  uint8_t temp;
  digitalWrite(16, 1);
  pinMode(16, OUTPUT);
  digitalWrite(16, !level);

  // Flash is on GPIO0
  pinMode(0, INPUT);
  temp = digitalRead(0);
  pinMode(0, OUTPUT); 
  return !temp;
}

void setup() {
  int ret;

  ESP.eraseConfig();

  // Set WiFi to station mode and disconnect from an AP if it was previously connected
  WiFi.mode(WIFI_AP_STA);
  SERIAL_DEBUG.begin(115200);
  SERIAL_DEBUG.println("\r\n========== SDK Saved parameters Start"); 
  WiFi.printDiag(SERIAL_DEBUG);
  SERIAL_DEBUG.println("========== SDK Saved parameters End"); 
  SERIAL_DEBUG.println("Connecting...");

  // Get current autoconnect state from SDK
  autoConnect = WiFi.getAutoConnect();
  WiFi.begin("DummySSID", "whateverkeyjustdontconnect");

  uint8_t timeout = 10; // 10 * 500 ms = 5 sec time out
  // 500ms loop
  while ( ((ret = WiFi.status()) != WL_CONNECTED) && timeout ) {
    SERIAL_DEBUG.print(".");
    delay(500);
    --timeout;
  }

  // connected ? disable AP, client mode only
  if ((ret = WiFi.status()) == WL_CONNECTED) {
    SERIAL_DEBUG.println("connected!");
    SERIAL_DEBUG.print("STA IP address "); 
    SERIAL_DEBUG.println(WiFi.localIP());
  // not connected ? start AP
  } else {
    //WiFi.mode(WIFI_AP);
    SERIAL_DEBUG.println("Configuring access point...");
    WiFi.softAP("ESP-SOFTAP","allowmeistooshort");
    WiFi.softAPIP();
    SERIAL_DEBUG.print("AP IP address "); 
    SERIAL_DEBUG.println(WiFi.softAPIP());
  }

  SERIAL_DEBUG.println("Starting loop");
}

void loop() {

  uint8_t btn = handle_key_led(autoConnect);

  // Debouncing
  if (btn != lastButtonState) {
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    // if the button state has changed:
    if (btn != buttonState) {
      buttonState = btn;

      // Only on button pressed, not released
      if (buttonState == HIGH) {
        autoConnect = !autoConnect;
        WiFi.setAutoConnect(autoConnect);
        SERIAL_DEBUG.print("Autoconnect will be now ");
        SERIAL_DEBUG.println(autoConnect);
        SERIAL_DEBUG.println("Restarting...");
        delay(500);
        // Changing Auto Connect in loop does nothing
        // it will be taken into account on reboot only 
        // see SDK wifi_station_set_auto_connect 
        ESP.reset();
      }
    }
  }

  lastButtonState = btn;
}

[vitorsilvalima]

Hi Hallard,

I just tried to test your code here and it just says the following:

WifiIssue:48: error: 'class ESP8266WiFiClass' has no member named 'getAutoConnect'
autoConnect = WiFi.getAutoConnect();
^
/home/vlima/Arduino/WifiIssue/WifiIssue.ino: In function 'void loop()':
WifiIssue:94: error: 'class ESP8266WiFiClass' has no member named 'setAutoConnect'
WiFi.setAutoConnect(autoConnect);
^
exit status 1
'class ESP8266WiFiClass' has no member named 'getAutoConnect'

Which version of the library are you using because mine has no getAtutoConnect function?

[hallard]

I'm using IDE 1.6.7 + Latest git version of Arduino-Esp8266

getAutoConnect has been committed on Dec 29th
4a68612#diff-170dccef5e4ac8c81a905fdfe877347f

[vitorsilvalima]

I see. I just installed it but now I've got another problem. The code of your sketch somehow is making my NODEMCU 1.0 restart forever even when I upload any other sketch to the board. The following characters is what I'm getting and they don't stop coming through.
�����E�V�KE�R|�����E�V�KE�R|���

[vitorsilvalima]

Actually, this is what I'm getting from the board:
Fatal exception (28):
epc1=0x40100524, epc2=0x00000000, epc3=0x00000000, excvaddr=0x00000001, depc=0x00000000

[hallard]

Do you still have the same problem with other example sketch ?

[vitorsilvalima]

Yes, I still have this same error with any other sketch now. What may have caused this issue? I have never seen it before

Sent from my Samsung device

-------- Original message --------
From: Charles notifications@github.com
Date: 2016-02-10 12:38 (GMT-03:00)
To: esp8266/Arduino Arduino@noreply.github.com
Cc: Vitor Silva Lima vitor.lima2@fatec.sp.gov.br
Subject: Re: [Arduino] Connection keeps droping when ESP8266 set up as an access point (#1615)

Do you still have the same problem with other example sketch ?

Reply to this email directly or view it on GitHubhttps://github.com//issues/1615#issuecomment-182400644.

[hallard]

Corrupted SDK Config by certainly flashing same device with different flash size between two flash (or sometime just changing board type)
try esptool with erase_flash flag, see #1010

[vitorsilvalima]

I got my board working again by uploading the blink sketch using Arduino version 1.6.5 and ESP8266 version 2. And somehow the other loose connection issue seems to have gone away.
ESP.eraseConfig();//caused my board to keep restarting
Serial.println(WiFi.getAutoConnect()); //returns true

void setup()
{
delay(1000);
Serial.begin(9600);
//WiFi.softAPConfig(ip, gateway, subnet);
WiFi.mode(WIFI_AP);
WiFi.softAP(ssid, password);
Serial.println("AP has started!");
Serial.println(WiFi.getAutoConnect());
server.begin();
pinMode(2,OUTPUT);
}
I tested this code and I don't know how but there is no package loss at all.

[hallard]

I think all of this cleared the "wrong thing" stored in by the SDK.
I'm pretty sure if you flash another example sketch which connect to your Wifi Network and then flash back this working sketch while powering off your Wifi Router the problem will came back.

So my point point of view is, until you're not connecting your device to a Wifi network, it will continue working fine.

[vitorsilvalima]

Hi Hallard,

I have just tested uploading an example that connects to the WIFI router and it worked fine and then I upload another example which configured the board as an AP and it also worked fine with pretty good ping results. It is hard to tell what was going on, we may have to read the SDK and try to see what is going on. However, I don't think SSID and PASSWORD are stored directly into the flash memory because it is only used at run time. Moreover, I believe nothing would change the flash memory in an explicit way. We really need to go over that sdk doc and check just to make sure. I will try with my other boards and see if they still have the connection issue and I will let you know. Nevertheless, thank you for your help.