Serial2 stopped working

[hayderismael]

Hello,

I appreciate that you put so much effort into making Nextion easy to use with your library. It is elegant.

I have used EasyNex myNex(Serial2) with ESP32 for the last two years, and it used to work perfectly. Nevertheless, It stopped yesterday when I tried it again.

Here is an example of how I used to use it: The Nextion first restarted with ESP32 and then went to page home.

This code used to work very well till yesterday.

I tried:
1- Use another ESP32 board ; not work. I still read what I print via the serial monitor.
2- I re-upload the code to an old ESP32, which worked before I flushed it and uploaded the code again. The MCU did not communicate after reuploading the code.
3- I used another Nextion display, it did not work.
4- Use the default Serial pins

EasyNex myNex(Serial);
It worked.

5- I used Arduino boards, Mega and Giga R1 WiFi with EasyNex myNex(Serial2) . It worked perfectly.

#include "EasyNextionLibrary.h" // Include EasyNextionLibrary
EasyNex myNex(Serial2);         //  Pin 16 = RXD2, Pin 17= TXD2
void setup() {
Serial.begin(115200);
delay(100);
Serial.println("Begin...");
delay(1000);
myNex.begin(115200);    // UART 2);   // Start with nextion bauds for serial communication.
Serial.println("reset1...");
myNex.writeStr("rest"); 
delay(1000); // wait till Nextion is restarted
myNex.writeStr("page home");  // Go to page home.
}

void loop() {
  //Put your main code here, to run repeatedly:
    Serial.println("loop...");
    delay(1000);
}

Then I used hardware serial between the EasyNex myNex(Serial2) as follows and it worked with all boards and displays.

#include <EasyNextionLibrary.h>
// Define the RX and TX pins for Serial 2
#define RXD2 16
#define TXD2 17
HardwareSerial mySerial(2);  // Initialize Serial 2
EasyNex myNex(mySerial);     // Pass the HardwareSerial object to EasyNex


void setup() {

  Serial.begin(115200);
  Serial.println("Begin...");
  delay(1000);
  mySerial.begin(115200, SERIAL_8N1, RXD2, TXD2);
  // Initialize the EasyNex object
  myNex.begin(115200);
  //myNex.begin(115200);    // UART 2);   // Start with nextion bauds for serial communication.
  Serial.println("reset1...");
  myNex.writeStr("rest");  
Serial.println("we go home...");
delay(1000); // wait till Nextion is restarted
  myNex.writeStr("page home"); 
  delay(100);
}

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

Would you please advise if something is wrong and why it doesn't work as it does in the fashion way?

Thanks for any help.

[Oleg-Perevyshin]

I confirm!
I also have something strange going on with the ports...
The application crashes and does not work.

ESP Exception Decoder
Sketch: DisplayBridge FQBN: esp32:esp32:esp32

Guru Meditation Error: Core  1 panic'ed (InstrFetchProhibited). Exception was unhandled.

Core  1 register dump:
PC      : 0x00000000  PS      : 0x00060630  A0      : 0x800d48f6  A1      : 0x3ffb21f0  
A2      : 0x3ffc14ec  A3      : 0x00000000  A4      : 0x00000001  A5      : 0x10624dd3  
A6      : 0x3ffbdbac  A7      : 0xb33fffff  A8      : 0x800d45b4  A9      : 0x000000fc  
A10     : 0x00000000  A11     : 0x00000000  A12     : 0x3ffb9090  A13     : 0x00000000  
A14     : 0x00000000  A15     : 0x00000000  SAR     : 0x0000000a  EXCCAUSE: 0x00000014  
EXCVADDR: 0x00000000  LBEG    : 0x40085d08  LEND    : 0x40085d12  LCOUNT  : 0x00000000  


Backtrace: 0xfffffffd:0x3ffb21f0 0x400d48f3:0x3ffb2210 0x400d4549:0x3ffb2230 0x400d432d:0x3ffb2250 0x400d77d8:0x3ffb2270 0x4008ab5a:0x3ffb2290

ELF file SHA256: bf5315c43f487f2e

Rebooting...

PC: 0x00000000
EXCVADDR: 0x00000000

Decoding stack results
0x400d48f3: EasyNex::readCommand() at c:\Users\perevyshin_oe\Documents\Arduino\libraries\Easy_Nextion_Library\src\readCustomCommands.cpp:61
0x400d4549: EasyNex::NextionListen() at c:\Users\perevyshin_oe\Documents\Arduino\libraries\Easy_Nextion_Library\src\EasyNextionLibrary.cpp:331
0x400d432d: loop() at E:\RockingStand\DisplayBridge\DisplayBridge.ino:95
0x400d77d8: loopTask(void*) at C:\Users\perevyshin_oe\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.0.4\cores\esp32\main.cpp:74
0x4008ab5a: vPortTaskWrapper at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/freertos/FreeRTOS-Kernel/portable/xtensa\port.c:162

The code is simple

#include <HardwareSerial.h>
#include <EasyNextionLibrary.h> /* https://github.com/Seithan/EasyNextionLibrary */
#include <Arduino_JSON.h>       /* https://github.com/arduino-libraries/Arduino_JSON */

#define DEBUG_RX 3
#define DEBUG_TX 1
HardwareSerial Serial_Debug(0);

#define BASE_RX 26
#define BASE_TX 25
HardwareSerial Serial_Base(1);

#define DISPLAY_RX 16
#define DISPLAY_TX 17
HardwareSerial Serial_Display(2);
EasyNex serial_display(Serial_Display);

template<typename T>
void DEBUG_PRINT(const String &argument, const T &value) {
  if (Serial_Debug) {
    Serial_Debug.print(argument);
    Serial_Debug.print(": ");
    Serial_Debug.println(value);
  }
}


void setup() {
  delay(100);

  Serial_Debug.begin(115200);
  while (!Serial_Debug) {}
  DEBUG_PRINT("DEBUG", "Init Debug Module");
  delay(250);

  Serial_Base.begin(115200, SERIAL_8N1, BASE_RX, BASE_TX);
  while (!Serial_Base) {}
  DEBUG_PRINT("DEBUG", "Base UATR Started");
  delay(250);

  Serial_Display.begin(115200, SERIAL_8N1, DISPLAY_RX, DISPLAY_TX);
  while (!Serial_Display) {}
  DEBUG_PRINT("DEBUG", "Display UATR Started");
  delay(250);

  send_to_display("page Boot");
  delay(4250);
  send_to_base("SYS", "Display Started", "");
}


void loop() {
  serial_display.NextionListen();
}

Debug Serial:

DEBUG: Init Debug Module
DEBUG: Base UATR Started
DEBUG: Display UATR Started
DEBUG: send_to_display: Command:  page Boot
DEBUG: send_to_base: Header:  SYS | Argument: Display Started | Value: 

After that the app crashes.
If you disconnect the wires from the display, the app works.
I noticed that it crashes when the display sends anything to the ESP32.