AP restarts instead of simply stop and network events are repeated · espressif/arduino-esp32 · Discussion #11113

enriquedbelec
Mar 12, 2025

Board

ESP32 Dev module

Device Description

ESP32-WROOM-32UE

Hardware Configuration

Version

v3.1.2

IDE Name

VSCode

Operating System

Windows 10

Flash frequency

40 Mhz

PSRAM enabled

Upload speed

115200

Description

Hi, I've discovered an issue that is not happening in old Arduino Core 2.X. When you start WiFi STA and AP at same time (tried also in the same channel), the AP reports events AP_START, AP_STOP and AP_START again. Also, if you manage to stop only the AP, it reports AP_STOP, AP_START, and AP_STOP. These duplicate events were not reported in Arduino Core 2.X by doing the same.

In stopAP() function, if I try to call to WiFi.softAPdisconnect(false); (with false), it reports AP_STOP, AP_START, so the AP is restarted and is never stopped.

If I don't start the STA by calling WiFi.begin(...), when it manages to start at setup, it reports AP_START, AP_STOP and AP_START. When it manages to stop, the AP also reports the events AP_STOP, AP_START, so is not stopped, or the events are a mess.

Sketch

#include <Arduino.h>
#include <WiFi.h>
const char *ssid = "your-ssid";
const char *password = "your-pasword";
const char *ssidAP = "ESP32";
const char *passwordAP = "12345678";
void networkEvent(WiFiEvent_t event) {
 switch (event) {
 case ARDUINO_EVENT_WIFI_READY: log_i("WiFi interface ready"); break;
 case ARDUINO_EVENT_WIFI_STA_START: log_i("WiFi STA started"); break;
 case ARDUINO_EVENT_WIFI_STA_STOP: log_i("WiFi STA stopped"); break;
 case ARDUINO_EVENT_WIFI_STA_CONNECTED: log_i("WiFi STA connected"); break;
 case ARDUINO_EVENT_WIFI_STA_DISCONNECTED: log_i("WiFi STA disconnected"); break;
 case ARDUINO_EVENT_WIFI_STA_AUTHMODE_CHANGE: log_i("WiFi STA authentication mode of access point has changed"); break;
 case ARDUINO_EVENT_WIFI_STA_GOT_IP:
 log_i("WIFI STA obtained IP address: %s", WiFi.localIP().toString().c_str());
 break;
 case ARDUINO_EVENT_WIFI_STA_LOST_IP: log_i("WIFI STA lost IP address and IP address is reset to 0"); break;
 
 case ARDUINO_EVENT_WIFI_AP_START: log_i("WiFi AP started"); break;
 case ARDUINO_EVENT_WIFI_AP_STOP: log_i("WiFi AP stopped"); break;
 case ARDUINO_EVENT_WIFI_AP_STACONNECTED: log_i("Client connected to AP"); break;
 case ARDUINO_EVENT_WIFI_AP_STADISCONNECTED: log_i("Client disconnected from AP"); break;
 case ARDUINO_EVENT_WIFI_AP_STAIPASSIGNED: log_i("AP assigned IP address to client"); break;
 case ARDUINO_EVENT_WIFI_AP_PROBEREQRECVED: log_i("AP received probe request"); break;
 default: break;
 }
}
void startAP(){
 int apChannel = WiFi.channel();
 int maxAPClients = 1;
 log_d("Let's start AP %s in channel %d...", ssidAP, apChannel);
 WiFi.softAP(ssidAP, passwordAP, apChannel, 0, maxAPClients);
}
void stopAP(){
 log_d("Let's stop AP...");
 WiFi.softAPdisconnect(true);
}
void setup() {
 delay(3000);
 Serial.begin(115200);
 
 // Listen for events
 Network.onEvent(networkEvent);
 // Do not save nothing automatically: we handle saving the credentials
 WiFi.persistent(false);
 // Begin STA
 WiFi.begin(ssid, password);
 // Better we manage the autoreconnect policy
 WiFi.setAutoReconnect(false);
 log_d("Starting AP...");
 // Start AP
 startAP();
}
void loop() {
 // We manage to stop and start the AP at regular intervals, to observe the events produced
 delay(15000);
 if(WiFi.AP.started()){
 stopAP();
 }else{
 startAP();
 }
}

Debug Message

[ 3537][I][main.cpp:12] networkEvent(): WiFi interface ready
[ 3614][I][main.cpp:13] networkEvent(): WiFi STA started
[ 3623][D][main.cpp:61] setup(): Starting AP...
[ 3633][D][main.cpp:36] startAP(): Let's start AP ESP32 in channel 6...
[ 3653][I][main.cpp:23] networkEvent(): WiFi AP started
=========== After Setup Start ============
INTERNAL Memory Info:
------------------------------------------ 
 Total Size : 336772 B ( 328.9 KB)
 Free Bytes : 239476 B ( 233.9 KB)
 Allocated Bytes : 87008 B ( 85.0 KB)
[ 3682][I][main.cpp:15] networkEvent(): WiFi STA connected
 Minimum Free Bytes: 236224 B ( 230.7 KB)
 Largest Free Block: 110580 B ( 108.0 KB)
------------------------------------------
GPIO Info:
------------------------------------------
 GPIO : BUS_TYPE[bus/unit][chan]
 -------------------------------------- 
 1 : UART_TX[0]
 3 : UART_RX[0]
============ After Setup End =============
[ 3927][I][main.cpp:19] networkEvent(): WIFI STA obtained IP address: 192.168.1.143
[ 18740][D][main.cpp:41] stopAP(): Let's stop AP...
[ 18750][I][main.cpp:24] networkEvent(): WiFi AP stopped
[ 18756][I][main.cpp:23] networkEvent(): WiFi AP started
[ 18762][I][main.cpp:24] networkEvent(): WiFi AP stopped
[ 33770][D][main.cpp:36] startAP(): Let's start AP ESP32 in channel 6...
[ 33783][I][main.cpp:23] networkEvent(): WiFi AP started
[ 33981][I][main.cpp:24] networkEvent(): WiFi AP stopped
[ 33987][I][main.cpp:23] networkEvent(): WiFi AP started
[ 48978][D][main.cpp:41] stopAP(): Let's stop AP...
[ 48988][I][main.cpp:24] networkEvent(): WiFi AP stopped
[ 48994][I][main.cpp:23] networkEvent(): WiFi AP started
[ 49000][I][main.cpp:24] networkEvent(): WiFi AP stopped
[ 64007][D][main.cpp:36] startAP(): Let's start AP ESP32 in channel 6...
[ 64020][I][main.cpp:23] networkEvent(): WiFi AP started
[ 64219][I][main.cpp:24] networkEvent(): WiFi AP stopped
[ 64225][I][main.cpp:23] networkEvent(): WiFi AP started
[ 79215][D][main.cpp:41] stopAP(): Let's stop AP...
[ 79225][I][main.cpp:24] networkEvent(): WiFi AP stopped
[ 79231][I][main.cpp:23] networkEvent(): WiFi AP started
[ 79237][I][main.cpp:24] networkEvent(): WiFi AP stopped
[ 94244][D][main.cpp:36] startAP(): Let's start AP ESP32 in channel 6...
[ 94257][I][main.cpp:23] networkEvent(): WiFi AP started
[ 94455][I][main.cpp:24] networkEvent(): WiFi AP stopped
[ 94461][I][main.cpp:23] networkEvent(): WiFi AP started
[109452][D][main.cpp:41] stopAP(): Let's stop AP...
[109462][I][main.cpp:24] networkEvent(): WiFi AP stopped
[109468][I][main.cpp:23] networkEvent(): WiFi AP started
[109474][I][main.cpp:24] networkEvent(): WiFi AP stopped
[124481][D][main.cpp:36] startAP(): Let's start AP ESP32 in channel 6...
[124494][I][main.cpp:23] networkEvent(): WiFi AP started
[124692][I][main.cpp:24] networkEvent(): WiFi AP stopped
[124698][I][main.cpp:23] networkEvent(): WiFi AP started
[139689][D][main.cpp:41] stopAP(): Let's stop AP...
[139699][I][main.cpp:24] networkEvent(): WiFi AP stopped
[139705][I][main.cpp:23] networkEvent(): WiFi AP started
[139711][I][main.cpp:24] networkEvent(): WiFi AP stopped
[154718][D][main.cpp:36] startAP(): Let's start AP ESP32 in channel 6...
[154731][I][main.cpp:23] networkEvent(): WiFi AP started
[154929][I][main.cpp:24] networkEvent(): WiFi AP stopped
[154935][I][main.cpp:23] networkEvent(): WiFi AP started
[169926][D][main.cpp:41] stopAP(): Let's stop AP...
[169936][I][main.cpp:24] networkEvent(): WiFi AP stopped
[169942][I][main.cpp:23] networkEvent(): WiFi AP started
[169948][I][main.cpp:24] networkEvent(): WiFi AP stopped
[184955][D][main.cpp:36] startAP(): Let's start AP ESP32 in channel 6...
[184970][I][main.cpp:23] networkEvent(): WiFi AP started
[185167][I][main.cpp:24] networkEvent(): WiFi AP stopped
[185173][I][main.cpp:23] networkEvent(): WiFi AP started
[200164][D][main.cpp:41] stopAP(): Let's stop AP...
[200174][I][main.cpp:24] networkEvent(): WiFi AP stopped
[200180][I][main.cpp:23] networkEvent(): WiFi AP started
[200186][I][main.cpp:24] networkEvent(): WiFi AP stopped
[215193][D][main.cpp:36] startAP(): Let's start AP ESP32 in channel 6...
[215206][I][main.cpp:23] networkEvent(): WiFi AP started
[215404][I][main.cpp:24] networkEvent(): WiFi AP stopped
[215410][I][main.cpp:23] networkEvent(): WiFi AP started
[230401][D][main.cpp:41] stopAP(): Let's stop AP...
[230411][I][main.cpp:24] networkEvent(): WiFi AP stopped
[230417][I][main.cpp:23] networkEvent(): WiFi AP started
[230423][I][main.cpp:24] networkEvent(): WiFi AP stopped
[245430][D][main.cpp:36] startAP(): Let's start AP ESP32 in channel 6...
[245443][I][main.cpp:23] networkEvent(): WiFi AP started
[245641][I][main.cpp:24] networkEvent(): WiFi AP stopped
[245647][I][main.cpp:23] networkEvent(): WiFi AP started
[260638][D][main.cpp:41] stopAP(): Let's stop AP...
[260648][I][main.cpp:24] networkEvent(): WiFi AP stopped
[260654][I][main.cpp:23] networkEvent(): WiFi AP started
[260660][I][main.cpp:24] networkEvent(): WiFi AP stopped

Other Steps to Reproduce

No response

I have checked existing issues, online documentation and the Troubleshooting Guide

I confirm I have checked existing issues, online documentation and Troubleshooting guide.

Replies: 2 comments 2 replies

me-no-dev
Mar 12, 2025
Maintainer

The reason why you see the calls is:

When you start AP, you are first starting the interface with the default configuration, then you are resetting that configuration to your needs. That requires AP to be stopped and restarted with the new config.
When you disconnect AP you first delete the config first, which causes the interface to restart with the default config and then the interface is turned off.

void startAP(){
 int apChannel = WiFi.channel();
 int maxAPClients = 1;
 log_d("Let's start AP %s in channel %d...", ssidAP, apChannel);
 WiFi.AP.begin();
 WiFi.AP.create(ssidAP, passwordAP, apChannel, 0, maxAPClients);
}
void stopAP(){
 log_d("Let's stop AP...");
 WiFi.AP.end();
}

0 replies

enriquedbelec
Mar 12, 2025
Author

Thank you for your response @me-no-dev. Is there a way to avoid this double stop/start or viceversa and avoid triple events, when the effect is only one event? In Arduino Core 2.X this does not happen.

PD: I've tested your code change, and the effect is that on first start the AP starts/stops/starts, and after on loop the interface is only stopped the first time. Next times, the AP_STOP event is never reported:

[ 3513][I][main.cpp:13] networkEvent(): WiFi interface ready
[ 3590][I][main.cpp:14] networkEvent(): WiFi STA started
[ 3598][D][main.cpp:74] setup(): Starting AP...
[ 3604][D][main.cpp:41] startAP(): Let's start AP ESP32...
[ 3616][I][main.cpp:24] networkEvent(): WiFi AP started 
=========== After Setup Start ============
[ 3814][I][main.cpp:25] networkEvent(): WiFi AP stopped
[ 3821][I][main.cpp:24] networkEvent(): WiFi AP started
INTERNAL Memory Info:
------------------------------------------
 Total Size : 336772 B ( 328.9 KB)
 Free Bytes : 240180 B ( 234.6 KB)
 Allocated Bytes : 86416 B ( 84.4 KB)
 Minimum Free Bytes: 239528 B ( 233.9 KB)
 Largest Free Block: 110580 B ( 108.0 KB)
------------------------------------------
GPIO Info:
------------------------------------------
 GPIO : BUS_TYPE[bus/unit][chan]
 --------------------------------------
 1 : UART_TX[0]
 3 : UART_RX[0]
============ After Setup End =============
[ 4674][I][main.cpp:16] networkEvent(): WiFi STA connected
[ 4943][I][main.cpp:20] networkEvent(): WIFI STA obtained IP address: 192.168.1.143
[ 18898][D][main.cpp:49] stopAP(): Let's stop AP...
[ 18907][I][main.cpp:25] networkEvent(): WiFi AP stopped
[ 33913][D][main.cpp:41] startAP(): Let's start AP ESP32...
[ 33928][I][main.cpp:24] networkEvent(): WiFi AP started
[ 48935][D][main.cpp:49] stopAP(): Let's stop AP...
[ 63943][D][main.cpp:41] startAP(): Let's start AP ESP32...
[ 63958][I][main.cpp:24] networkEvent(): WiFi AP started
[ 78965][D][main.cpp:49] stopAP(): Let's stop AP...
[ 93972][D][main.cpp:41] startAP(): Let's start AP ESP32...
[ 93987][I][main.cpp:24] networkEvent(): WiFi AP started
[108993][D][main.cpp:49] stopAP(): Let's stop AP...
[124001][D][main.cpp:41] startAP(): Let's start AP ESP32...
[124016][I][main.cpp:24] networkEvent(): WiFi AP started
[139022][D][main.cpp:49] stopAP(): Let's stop AP...
[154030][D][main.cpp:41] startAP(): Let's start AP ESP32...
[154045][I][main.cpp:24] networkEvent(): WiFi AP started
[169051][D][main.cpp:49] stopAP(): Let's stop AP...
[184059][D][main.cpp:41] startAP(): Let's start AP ESP32...
[184074][I][main.cpp:24] networkEvent(): WiFi AP started

2 replies

@me-no-dev

me-no-dev Mar 13, 2025
Maintainer

Not what I see:

[ 79231][D][sketch_mar13b.ino:42] stopAP(): Let's stop AP...
[ 79255][I][sketch_mar13b.ino:24] networkEvent(): WiFi AP stopped
[ 94267][D][sketch_mar13b.ino:36] startAP(): Let's start AP ESP32 in channel 1...
[ 94298][I][sketch_mar13b.ino:23] networkEvent(): WiFi AP started
[109309][D][sketch_mar13b.ino:42] stopAP(): Let's stop AP...
[109333][I][sketch_mar13b.ino:24] networkEvent(): WiFi AP stopped

@me-no-dev

me-no-dev Mar 13, 2025
Maintainer

this is with your sketch as you have provided it and only replaced the AP methods like I suggested above. Both events come and only once. I explained why your original code produces double events

Uh oh!

AP restarts instead of simply stop and network events are repeated #11113

Uh oh!

enriquedbelec Mar 12, 2025

Board

Device Description

Hardware Configuration

Version

IDE Name

Operating System

Flash frequency

PSRAM enabled

Upload speed

Description

Sketch

Debug Message

Other Steps to Reproduce

I have checked existing issues, online documentation and the Troubleshooting Guide

Replies: 2 comments · 2 replies

Uh oh!

me-no-dev Mar 12, 2025 Maintainer

Uh oh!

Uh oh!

enriquedbelec Mar 12, 2025 Author

Uh oh!

me-no-dev Mar 13, 2025 Maintainer

Uh oh!

me-no-dev Mar 13, 2025 Maintainer

enriquedbelec
Mar 12, 2025

Replies: 2 comments 2 replies

me-no-dev
Mar 12, 2025
Maintainer

enriquedbelec
Mar 12, 2025
Author

me-no-dev Mar 13, 2025
Maintainer

me-no-dev Mar 13, 2025
Maintainer