Arduino: No WiFi connect since 2.3.0 if delay >= 1000 in setup() for init of external hardware

[heiko-wolf]

Hardware

Hardware: ESP-12
Core Version: 2.3.0

Description

No WiFi connect since 2.3.0 if "delay >= 1000" in setup() for init of external hardware.
After upgrading to 2.3.0 many sketches wont connect anymore to WiFi Accesspoint.
Testing a few things showed up that the problem was caused by adding a delay(1000) in setup before WiFi.begin().
This was done to power up external hardware properly before starting the Arduino/ESP Code and connecting the WiFi.
After downgrading to 2.2.0 everything works fine again using this delay.

Settings in IDE

Module: Wemos D1 R2 & mini
Flash Size: 4MB/3MB
CPU Frequency: 80Mhz

Sketch

include

char ssid[50] = "your ssid";
char password[50] = "your pwd";

void setup() {
Serial.begin(9600);

delay(1000); // for ext. hardware init <<<<<<<<<<<

Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);

WiFi.begin(ssid, password);

while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}

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

void loop() {
delay(1000);
Serial.println("X");
}

[kendo55]

i had that problem too !!! The Problem is not the delay().....

FIX FOR USING 2.3.0 CORE (only .begin if not connected)!!!!!!!

if (WiFi.status() != WL_CONNECTED) {     // FIX FOR USING 2.3.0 CORE (only .begin if not connected)
    WiFi.begin(ssid, password); // connect to the network
}
while (WiFi.status() != WL_CONNECTED) {
    delay(500);
Serial.print(".");
}

see:
(https://github.com/esp8266/Arduino/issues/2186)
and:
(https://github.com/esp8266/Arduino/issues/2594)

[heiko-wolf]

Hi there,
youre right, after adding a WiFi.mode(WIFI_OFF) at the beginning of setup() and enable it just directly before WiFi.begin() after all other stuff is done and a few delays later averything works fine again :)
Thanks for pointing to the other issues !!

[cimba007]

Got the same problem but none of the workarounds seems to fix it.
I do quite some heavy init stuff (> 1sec) and put WiFi.mode(WIFI_OFF); at the beginning of setup.

After my >1sec seconds I do this

WiFi.mode(WIFI_STA); listNetworks(0); if (WiFi.status() != WL_CONNECTED) { // FIX FOR USING 2.3.0 CORE (only .begin if not connected) WiFi.begin(ssid, password); // connect to the network }
Still sometimes I got no networks found and after that no connection ..
....wifi evt: 1 STA disconnect: 201 ....wifi evt: 1 STA disconnect: 201 .....wifi evt: 1 STA disconnect: 201

After a clean power cycle the whole thing is working, just after flashing or sometimes on power-cycling from battery it is not working.

[mlord]

Try using static IP rather than DHCP -- fixes it for me here. The internal DHCP seems to have issues under some conditions.

[johnwa27]

I just discovered this wonderful feature 😡. The workaround suggested in kendo55's post begs the question, "why is the module connected prior to WiFi.begin?". The workaround could be problematic if there is more than 1 AP and you need to connect to one specific one or change from one to the other.
I added a WiFi.disconnect() before WiFi.begin(). So far it has worked and I think it is a more robust solution.