ESP32 Forum

Posted: **Mon Feb 16, 2026 11:19 am**

Good afternoon
Please tell me why the EPS32 is constantly rebooting?
I'm loading a sketch:

#include "Arduino.h"
#include "ESPAsyncWebServer.h"
#include "AsyncTCP.h"
#include <WiFi.h>
#include <Wire.h>
#include <SPIFFS.h>
#include <painlessMesh.h>

const char* ssid     = "ESP32";
const char* password = "123456789";
IPAddress IP(192,168,2,1);
IPAddress gateway(192,168,2,1);
IPAddress subnet(255,255,255,0);

AsyncWebServer server(80);
 
void setup()
{
  Serial.begin(115200);
  
  Serial.print("Setting AP (Access Point)…");
  WiFi.softAP(ssid, password);
  delay(500);
  WiFi.softAPConfig(IP, gateway, subnet);    
  IPAddress IP = WiFi.softAPIP();
  Serial.print("AP IP address: ");
  Serial.println(IP);

  if (!SPIFFS.begin(true)) Serial.println("An Error has occurred while mounting SPIFFS");
  else Serial.println("SPIFFS -> OK");

  server.on("/", HTTP_GET, [](AsyncWebServerRequest *request){
    request->send(SPIFFS, "/index.html", String(), false);
  });
  
  server.on("/index.html", HTTP_GET, [](AsyncWebServerRequest * request) {
    request->send(SPIFFS, "/index.html", String(), false);    });

  // Route to load style.css file
  server.on("/style.css", HTTP_GET, [](AsyncWebServerRequest *request){
    request->send(SPIFFS, "/style.css", "text/css");          });

//  server.begin();
  delay (1000);
}
 
void loop(){
  
}

Once I uncomment the line

Code: Select all

server.begin();

The ESP32 starts rebooting and displays the following message:

Code: Select all

ELF file SHA256: c2b1b4fdc

Rebooting...
ets Jul 29 2019 12:21:46

rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0030,len:4980
load:0x40078000,len:16612
load:0x40080400,len:3500
entry 0x400805b4
Setting AP (Access Point)…AP IP address: 192.168.2.1
SPIFFS -> OK

assert failed: tcp_alloc /IDF/components/lwip/lwip/src/core/tcp.c:1854 (Required to lock TCPIP core functionality!)


Backtrace: 0x4008bc04:0x3ffb1f90 0x4008bbc9:0x3ffb1fb0 0x40092109:0x3ffb1fd0 0x400fa607:0x3ffb2110 0x400fa77d:0x3ffb2130 0x400dc420:0x3ffb2150 0x400da09e:0x3ffb2190 0x400d2e34:0x3ffb21b0 0x400e6d82:0x3ffb2270 0x4008cb15:0x3ffb2290

Posted: **Tue Feb 17, 2026 6:06 pm**

You would need to decode the backtrace for a clear answer.

Your example does not crash for me. Make sure ESPAsyncWebServer and AsyncTCP are at the latest versions.

Posted: **Tue Feb 17, 2026 8:32 pm**

Try to use a Dev Module Board for your ESP32, with Programer Mode: esptool + CDC on (Upload Mode config in Tools). There might be a incompatibility between the specifications of your board and your computer. I had some issues running my Nano ESP32S3 in my mac, this was the only config I could use to stabilise it. And now, with platform.io I needed to do the same. Hope it helps!

ESP32 Forum

EPS32 is constantly rebooting

EPS32 is constantly rebooting

Re: EPS32 is constantly rebooting

Re: EPS32 is constantly rebooting