[GH-ISSUE #1100] ESP losing connection every 10 days #941

New issue

Open

opened 2026-02-28 01:27:46 +03:00 by kerem · 5 comments

kerem commented 2026-02-28 01:27:46 +03:00

Owner

Copy link

Originally created by @jeffersonpimenta on GitHub (Jul 26, 2020).
Original GitHub issue: https://github.com/tzapu/WiFiManager/issues/1100

Hi, iam using WifiManager with one sonoff mini and I notice that ESP loses connection every 10 days or so. Iam using the code to simulate a Modbus protocol in ScadaLTS. My disconnections occur:

Iam using pihole with 24h lease time. My ESP don't change ip, even when it lost connection and i put my wifi pass again.

Any ideas? My code is:

#include <DNSServer.h>
#include <ESP8266WebServer.h>
#include <WiFiManager.h>

int ModbusTCP_port = 502;

int SONOFF_LED = 13; //led built in
int SONOFF_RELAY = 12;//rele
int SONOFF_INPUT = 4;//entrada
int SONOFF_BOTAO = 0;//botão

//////// Required for Modbus TCP / IP /// Requerido para Modbus TCP/IP /////////
#define maxInputRegister 20
#define maxHoldingRegister 20

#define MB_FC_NONE 0
#define MB_FC_READ_REGISTERS 3 //implemented
#define MB_FC_WRITE_REGISTER 6 //implemented
#define MB_FC_WRITE_MULTIPLE_REGISTERS 16 //implemented
//
// MODBUS Error Codes
//
#define MB_EC_NONE 0
#define MB_EC_ILLEGAL_FUNCTION 1
#define MB_EC_ILLEGAL_DATA_ADDRESS 2
#define MB_EC_ILLEGAL_DATA_VALUE 3
#define MB_EC_SLAVE_DEVICE_FAILURE 4
//
// MODBUS MBAP offsets
//
#define MB_TCP_TID 0
#define MB_TCP_PID 2
#define MB_TCP_LEN 4
#define MB_TCP_UID 6
#define MB_TCP_FUNC 7
#define MB_TCP_REGISTER_START 8
#define MB_TCP_REGISTER_NUMBER 10

byte ByteArray[260];
unsigned int MBHoldingRegister[maxHoldingRegister];

//////////////////////////////////////////////////////////////////////////

WiFiServer MBServer(ModbusTCP_port);

void setup() {

pinMode(SONOFF_LED, OUTPUT);
pinMode(SONOFF_RELAY, OUTPUT);
pinMode(SONOFF_INPUT, INPUT);

Serial.begin(115200);

WiFiManager wifiManager;

for (int inicializ = 0; inicializ <= 25; inicializ++) {
digitalWrite(SONOFF_LED, HIGH);
delay(100);
digitalWrite(SONOFF_LED, LOW);
delay(100);

if (!digitalRead(SONOFF_BOTAO)) {
  digitalWrite(SONOFF_LED, HIGH);
  delay(500);
  digitalWrite(SONOFF_LED, LOW);
  delay(500);
  digitalWrite(SONOFF_LED, HIGH);
  delay(500);
  digitalWrite(SONOFF_LED, LOW);
  delay(500);
  digitalWrite(SONOFF_LED, HIGH);
  delay(500);
  digitalWrite(SONOFF_LED, LOW);
  delay(500);

  if (digitalRead(SONOFF_BOTAO)) {
    wifiManager.resetSettings();
    break;
  }
}

}

wifiManager.autoConnect();
Serial.println("connected...yeey :)");
digitalWrite(SONOFF_LED, HIGH);
delay(2000);
digitalWrite(SONOFF_LED, LOW);
delay(2000);
digitalWrite(SONOFF_LED, HIGH);

MBServer.begin();
Serial.println("Connected ");
Serial.print("ESP8266 Slave Modbus TCP/IP ");
Serial.print(WiFi.localIP());
Serial.print(":");
Serial.println(String(ModbusTCP_port));
Serial.println("Modbus TCP/IP Online");

}

void loop() {
// put your main code here, to run repeatedly:

// Check if a client has connected // Modbus TCP/IP
WiFiClient client = MBServer.available();
if (!client) {
return;
}

boolean flagClientConnected = 0;
byte byteFN = MB_FC_NONE;
int Start;
int WordDataLength;
int ByteDataLength;
int MessageLength;

// Modbus TCP/IP
while (client.connected()) {

if (client.available())
{
  flagClientConnected = 1;
  int i = 0;
  while (client.available())
  {
    ByteArray[i] = client.read();
    i++;
  }

  client.flush();

  ///////// Holding Register [0] A [9] = 10 Holding Registers Escritura
  ///////// Holding Register [0] A [9] = 10 Holding Registers Writing


  MBHoldingRegister[0] = !digitalRead(SONOFF_INPUT);
  // MBHoldingRegister[1] = 2;
  // MBHoldingRegister[2] = 3;
  // MBHoldingRegister[3] = 4;
  // MBHoldingRegister[4] = 5;
  // MBHoldingRegister[5] = 6;
  // MBHoldingRegister[6] = 7;
  // MBHoldingRegister[7] = 8;
  // MBHoldingRegister[8] = 9;
  // MBHoldingRegister[9] = 10;




  ///////// Holding Register [10] A [19] = 10 Holding Registers Lectura
  ///// Holding Register [10] A [19] = 10 Holding Registers Reading

  //int Temporal[10];

  // Temporal[0] = MBHoldingRegister[10];
  // Temporal[1] = MBHoldingRegister[11];
  // Temporal[2] = MBHoldingRegister[12];
  // Temporal[3] = MBHoldingRegister[13];
  // Temporal[4] = MBHoldingRegister[14];
  // Temporal[5] = MBHoldingRegister[15];
  // Temporal[6] = MBHoldingRegister[16];
  // Temporal[7] = MBHoldingRegister[17];
  // Temporal[8] = MBHoldingRegister[18];
  // Temporal[9] = MBHoldingRegister[19];

  /// Enable Output 14
  // digitalWrite(14, MBHoldingRegister[14] );

  digitalWrite(SONOFF_RELAY, MBHoldingRegister[10]);
  //// debug

  // for (int i = 0; i < 10; i++) {

  // Serial.print("[");
  // Serial.print(i);
  // Serial.print("] ");
  // Serial.print(Temporal[i]);

  // }
  // Serial.println("");


  //// rutine Modbus TCP
  byteFN = ByteArray[MB_TCP_FUNC];
  Start = word(ByteArray[MB_TCP_REGISTER_START], ByteArray[MB_TCP_REGISTER_START + 1]);
  WordDataLength = word(ByteArray[MB_TCP_REGISTER_NUMBER], ByteArray[MB_TCP_REGISTER_NUMBER + 1]);
}

// Handle request

switch (byteFN) {
  case MB_FC_NONE:
    break;

  case MB_FC_READ_REGISTERS: // 03 Read Holding Registers
    ByteDataLength = WordDataLength * 2;
    ByteArray[5] = ByteDataLength + 3; //Number of bytes after this one.
    ByteArray[8] = ByteDataLength; //Number of bytes after this one (or number of bytes of data).
    for (int i = 0; i < WordDataLength; i++)
    {
      ByteArray[ 9 + i * 2] = highByte(MBHoldingRegister[Start + i]);
      ByteArray[10 + i * 2] = lowByte(MBHoldingRegister[Start + i]);
    }
    MessageLength = ByteDataLength + 9;
    client.write((const uint8_t *)ByteArray, MessageLength);

    byteFN = MB_FC_NONE;

    break;


  case MB_FC_WRITE_REGISTER: // 06 Write Holding Register
    MBHoldingRegister[Start] = word(ByteArray[MB_TCP_REGISTER_NUMBER], ByteArray[MB_TCP_REGISTER_NUMBER + 1]);
    ByteArray[5] = 6; //Number of bytes after this one.
    MessageLength = 12;
    client.write((const uint8_t *)ByteArray, MessageLength);
    byteFN = MB_FC_NONE;
    break;

  case MB_FC_WRITE_MULTIPLE_REGISTERS: //16 Write Holding Registers
    ByteDataLength = WordDataLength * 2;
    ByteArray[5] = ByteDataLength + 3; //Number of bytes after this one.
    for (int i = 0; i < WordDataLength; i++)
    {
      MBHoldingRegister[Start + i] = word(ByteArray[ 13 + i * 2], ByteArray[14 + i * 2]);
    }
    MessageLength = 12;
    client.write((const uint8_t *)ByteArray, MessageLength);
    byteFN = MB_FC_NONE;

    break;
}

}

}

Originally created by @jeffersonpimenta on GitHub (Jul 26, 2020). Original GitHub issue: https://github.com/tzapu/WiFiManager/issues/1100 Hi, iam using WifiManager with one sonoff mini and I notice that ESP loses connection every 10 days or so. Iam using the code to simulate a Modbus protocol in ScadaLTS. My disconnections occur:    Iam using pihole with 24h lease time. My ESP don't change ip, even when it lost connection and i put my wifi pass again.   Any ideas? My code is: > #include <DNSServer.h> > #include <ESP8266WebServer.h> > #include <WiFiManager.h> > > > int ModbusTCP_port = 502; > > int SONOFF_LED = 13; //led built in > int SONOFF_RELAY = 12;//rele > int SONOFF_INPUT = 4;//entrada > int SONOFF_BOTAO = 0;//botão > > //////// Required for Modbus TCP / IP /// Requerido para Modbus TCP/IP ///////// > #define maxInputRegister 20 > #define maxHoldingRegister 20 > > #define MB_FC_NONE 0 > #define MB_FC_READ_REGISTERS 3 //implemented > #define MB_FC_WRITE_REGISTER 6 //implemented > #define MB_FC_WRITE_MULTIPLE_REGISTERS 16 //implemented > // > // MODBUS Error Codes > // > #define MB_EC_NONE 0 > #define MB_EC_ILLEGAL_FUNCTION 1 > #define MB_EC_ILLEGAL_DATA_ADDRESS 2 > #define MB_EC_ILLEGAL_DATA_VALUE 3 > #define MB_EC_SLAVE_DEVICE_FAILURE 4 > // > // MODBUS MBAP offsets > // > #define MB_TCP_TID 0 > #define MB_TCP_PID 2 > #define MB_TCP_LEN 4 > #define MB_TCP_UID 6 > #define MB_TCP_FUNC 7 > #define MB_TCP_REGISTER_START 8 > #define MB_TCP_REGISTER_NUMBER 10 > > byte ByteArray[260]; > unsigned int MBHoldingRegister[maxHoldingRegister]; > > ////////////////////////////////////////////////////////////////////////// > > WiFiServer MBServer(ModbusTCP_port); > > void setup() { > > pinMode(SONOFF_LED, OUTPUT); > pinMode(SONOFF_RELAY, OUTPUT); > pinMode(SONOFF_INPUT, INPUT); > > Serial.begin(115200); > > WiFiManager wifiManager; > > for (int inicializ = 0; inicializ <= 25; inicializ++) { > digitalWrite(SONOFF_LED, HIGH); > delay(100); > digitalWrite(SONOFF_LED, LOW); > delay(100); > > if (!digitalRead(SONOFF_BOTAO)) { > digitalWrite(SONOFF_LED, HIGH); > delay(500); > digitalWrite(SONOFF_LED, LOW); > delay(500); > digitalWrite(SONOFF_LED, HIGH); > delay(500); > digitalWrite(SONOFF_LED, LOW); > delay(500); > digitalWrite(SONOFF_LED, HIGH); > delay(500); > digitalWrite(SONOFF_LED, LOW); > delay(500); > > if (digitalRead(SONOFF_BOTAO)) { > wifiManager.resetSettings(); > break; > } > } > } > > > > wifiManager.autoConnect(); > Serial.println("connected...yeey :)"); > digitalWrite(SONOFF_LED, HIGH); > delay(2000); > digitalWrite(SONOFF_LED, LOW); > delay(2000); > digitalWrite(SONOFF_LED, HIGH); > > > MBServer.begin(); > Serial.println("Connected "); > Serial.print("ESP8266 Slave Modbus TCP/IP "); > Serial.print(WiFi.localIP()); > Serial.print(":"); > Serial.println(String(ModbusTCP_port)); > Serial.println("Modbus TCP/IP Online"); > > } > > void loop() { > // put your main code here, to run repeatedly: > > > // Check if a client has connected // Modbus TCP/IP > WiFiClient client = MBServer.available(); > if (!client) { > return; > } > > boolean flagClientConnected = 0; > byte byteFN = MB_FC_NONE; > int Start; > int WordDataLength; > int ByteDataLength; > int MessageLength; > > // Modbus TCP/IP > while (client.connected()) { > > if (client.available()) > { > flagClientConnected = 1; > int i = 0; > while (client.available()) > { > ByteArray[i] = client.read(); > i++; > } > > client.flush(); > > ///////// Holding Register [0] A [9] = 10 Holding Registers Escritura > ///////// Holding Register [0] A [9] = 10 Holding Registers Writing > > > MBHoldingRegister[0] = !digitalRead(SONOFF_INPUT); > // MBHoldingRegister[1] = 2; > // MBHoldingRegister[2] = 3; > // MBHoldingRegister[3] = 4; > // MBHoldingRegister[4] = 5; > // MBHoldingRegister[5] = 6; > // MBHoldingRegister[6] = 7; > // MBHoldingRegister[7] = 8; > // MBHoldingRegister[8] = 9; > // MBHoldingRegister[9] = 10; > > > > > ///////// Holding Register [10] A [19] = 10 Holding Registers Lectura > ///// Holding Register [10] A [19] = 10 Holding Registers Reading > > //int Temporal[10]; > > // Temporal[0] = MBHoldingRegister[10]; > // Temporal[1] = MBHoldingRegister[11]; > // Temporal[2] = MBHoldingRegister[12]; > // Temporal[3] = MBHoldingRegister[13]; > // Temporal[4] = MBHoldingRegister[14]; > // Temporal[5] = MBHoldingRegister[15]; > // Temporal[6] = MBHoldingRegister[16]; > // Temporal[7] = MBHoldingRegister[17]; > // Temporal[8] = MBHoldingRegister[18]; > // Temporal[9] = MBHoldingRegister[19]; > > /// Enable Output 14 > // digitalWrite(14, MBHoldingRegister[14] ); > > digitalWrite(SONOFF_RELAY, MBHoldingRegister[10]); > //// debug > > // for (int i = 0; i < 10; i++) { > > // Serial.print("["); > // Serial.print(i); > // Serial.print("] "); > // Serial.print(Temporal[i]); > > // } > // Serial.println(""); > > > //// rutine Modbus TCP > byteFN = ByteArray[MB_TCP_FUNC]; > Start = word(ByteArray[MB_TCP_REGISTER_START], ByteArray[MB_TCP_REGISTER_START + 1]); > WordDataLength = word(ByteArray[MB_TCP_REGISTER_NUMBER], ByteArray[MB_TCP_REGISTER_NUMBER + 1]); > } > > // Handle request > > switch (byteFN) { > case MB_FC_NONE: > break; > > case MB_FC_READ_REGISTERS: // 03 Read Holding Registers > ByteDataLength = WordDataLength * 2; > ByteArray[5] = ByteDataLength + 3; //Number of bytes after this one. > ByteArray[8] = ByteDataLength; //Number of bytes after this one (or number of bytes of data). > for (int i = 0; i < WordDataLength; i++) > { > ByteArray[ 9 + i * 2] = highByte(MBHoldingRegister[Start + i]); > ByteArray[10 + i * 2] = lowByte(MBHoldingRegister[Start + i]); > } > MessageLength = ByteDataLength + 9; > client.write((const uint8_t *)ByteArray, MessageLength); > > byteFN = MB_FC_NONE; > > break; > > > case MB_FC_WRITE_REGISTER: // 06 Write Holding Register > MBHoldingRegister[Start] = word(ByteArray[MB_TCP_REGISTER_NUMBER], ByteArray[MB_TCP_REGISTER_NUMBER + 1]); > ByteArray[5] = 6; //Number of bytes after this one. > MessageLength = 12; > client.write((const uint8_t *)ByteArray, MessageLength); > byteFN = MB_FC_NONE; > break; > > case MB_FC_WRITE_MULTIPLE_REGISTERS: //16 Write Holding Registers > ByteDataLength = WordDataLength * 2; > ByteArray[5] = ByteDataLength + 3; //Number of bytes after this one. > for (int i = 0; i < WordDataLength; i++) > { > MBHoldingRegister[Start + i] = word(ByteArray[ 13 + i * 2], ByteArray[14 + i * 2]); > } > MessageLength = 12; > client.write((const uint8_t *)ByteArray, MessageLength); > byteFN = MB_FC_NONE; > > break; > } > } > > > }

kerem commented 2026-02-28 01:27:47 +03:00

Author

Owner

Copy link

@dontsovcmc commented on GitHub (Aug 14, 2020):

Can router be a reason of losing connection? There is an IP lifetime in every routers.

<!-- gh-comment-id:674285072 --> @dontsovcmc commented on GitHub (Aug 14, 2020): Can router be a reason of losing connection? There is an IP lifetime in every routers.

kerem commented 2026-02-28 01:27:47 +03:00

Author

Owner

Copy link

@jeffersonpimenta commented on GitHub (Aug 15, 2020):

I use pihole to provinde IPs, since first setup every machine got same ip and it didnt change...

<!-- gh-comment-id:674317899 --> @jeffersonpimenta commented on GitHub (Aug 15, 2020): I use pihole to provinde IPs, since first setup every machine got same ip and it didnt change...

kerem commented 2026-02-28 01:27:47 +03:00

Author

Owner

Copy link

@uski commented on GitHub (Oct 4, 2020):

What are you doing to regain connection ?
I would suggest logging the serial output of the ESP to see what happens. Without further information it is very difficult to help you

<!-- gh-comment-id:703183459 --> @uski commented on GitHub (Oct 4, 2020): What are you doing to regain connection ? I would suggest logging the serial output of the ESP to see what happens. Without further information it is very difficult to help you

kerem commented 2026-02-28 01:27:47 +03:00

Author

Owner

Copy link

@jeffersonpimenta commented on GitHub (Oct 5, 2020):

To reconnect i need to log in web interface and reconfigure everything. Since I'm using an Sonoff standalone i haven't access to the terminal messages.

<!-- gh-comment-id:703341594 --> @jeffersonpimenta commented on GitHub (Oct 5, 2020): To reconnect i need to log in web interface and reconfigure everything. Since I'm using an Sonoff standalone i haven't access to the terminal messages.

kerem commented 2026-02-28 01:27:47 +03:00

Author

Owner

Copy link

@EgHubs commented on GitHub (Nov 27, 2020):

This might help

<!-- gh-comment-id:734730371 --> @EgHubs commented on GitHub (Nov 27, 2020): [This ](https://internetofhomethings.com/homethings/?p=396#comment-28503) might help

Sign in to join this conversation.

No Branch/Tag specified

Branches Tags

master

revert-1849-master

feature_fastconnect

feature_auth

feature_slimable

PEAP

feature_statichtmlparams

feature_asyncwebserver

feature_pagestringsref

parameter-smart-ptr

gh-pages

Legacy_v1

hotfixes

autochannelselect_feature

travis

smartconfig

v2.0.17

v2.0.16-rc.2

v2.0.15-rc.1

v2.0.0-rc.1

v2.0.14-beta

v2.0.13-beta

v2.0.12-beta

v2.0.11-beta

v2.0.10-beta

v2.0.9-beta

v2.0.8-beta

2.0.7-beta

2.0.6-beta

2.0.5-beta

2.0.4-beta

0.16.0

2.0.3-alpha

0.15.0

0.14

0.13

0.12

0.11

0.10

0.9

0.8

0.7

0.6

0.5

v0.4

v0.3

v0.2

v0.1

Labels

Clear labels   

📶 WiFi

  

🕸️ HTTP

  

Branch

  

DEV Help Wanted

  

Discussion

  

Documentation

  

ESP32

  

Example

  

Good First Issue

  

Hotfix

  

In Progress

  

Incomplete

  

Needs Feeback

  

Priority

  

QA

  

Question

  

Task

  

Upstream/Dependancy

  

bug

  

duplicate

  

enhancement

  

invalid

  

pull-request

Mirrored from GitHub Pull Request

  

wontfix

No labels

📶 WiFi

🕸️ HTTP

Branch

DEV Help Wanted

Discussion

Documentation

ESP32

Example

Good First Issue

Hotfix

In Progress

Incomplete

Needs Feeback

Priority

QA

Question

Task

Upstream/Dependancy

bug

duplicate

enhancement

invalid

pull-request

wontfix

Milestone

Clear milestone

No items

No milestone

Projects

Clear projects

No items

No project

Assignees

Clear assignees

No assignees

1 participant

Notifications

Subscribe

Due date

The due date is invalid or out of range. Please use the format "yyyy-mm-dd".

No due date set.

Dependencies

No dependencies set.

Reference

starred/WiFiManager#941

No description provided.