Nextion get value (Arduino Mega)

Projects Programming
1

Hello,

I am now struggling for quite a while with the Nextion display and Arduino Mega. I have a working project where sending the data from Arduino to Nextion is ok but from Nextion to Arduino I just can't get it.

I read tons of forums and pages but regardless of what I do I only always get number 0 or nothing from Nextion. I am using the default Nextion library.

I would really appreciate it if someone could share a working code so I can try to get the values from Nextion (7 inch intelligent) to Arduino Mega. Simple idea is button push -> read number value as int.

Thanks everyone who could help me

2

Please post your attempt and someone will be glad to help you.

3

I am sending the code. this version is returning 0 every time I push the button. I also tried reading the text as you will see but also nothing (0). I just can't get it working.

#include "Nextion.h" 

NexButton b1_sonda          = NexButton(7, 8, "b1_sonda"); //x15a
NexButton b_test            = NexButton(7, 22, "b_test"); //x15a


NexNumber n_tempsonda1        = NexNumber(7, 20, "n_tempsonda1");
NexNumber n_tempsonda11        = NexNumber(2, 53, "n_tempsonda11");
NexText t1_Sonda1a          = NexText(7, 21, "t1_Sonda1a"); //x15a
NexPage page0 = NexPage(0, 0, "page0");  // Page added as a touch event
NexPage page2 = NexPage(2, 0, "page2");  // Page added as a touch event
NexPage page7 = NexPage(7, 0, "page7");  // Page added as a touch event

char buffer[100] = {0}; //x15a

NexTouch *nex_listen_list[] = 
{
    
    &b1_sonda,
    &n_tempsonda11,
    &n_tempsonda1,
    &t1_Sonda1a,
    &b_test,
    &page0,  
    &page2,  
    &page7,  
    
    
    NULL
};

void b_testPopCallback(void *ptr)
{
    
    //float numbers1;
    //memset(buffer, 0, sizeof(buffer));
    //t1_Sonda1a.getText(buffer, sizeof(buffer));
    //numbers1 = atof(buffer);
 
    //Serial.print("SONDA_1a :");
    //Serial.println(numbers1);
    
    uint32_t number2 = 0;  // Create variable to store value of slider
    n_tempsonda1.getValue(&number2);  // Read the value of the slider
  
    //uint32_t numbers14 = 0;
    //char sonda1[10] = {0};
    //n_tempsonda1.getValue(&numbers14);
    //utoa(numbers14, sonda1, 10);
    if(number2==0){  // If I got a 0, then recheck:
    n_tempsonda1.getValue(&number2);  // Read the value of the slider
  }
  if(number2==0){  // If I got a 0, then recheck:
    n_tempsonda1.getValue(&number2);  // Read the value of the slider
  }
    
    Serial.print("SONDA_1 :");
    Serial.println(number2);
    Serial.write(0xff);  
    Serial.write(0xff);
    Serial.write(0xff);
}

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

     
    b_test.attachPop(b_testPopCallback);

}

void loop() {
  nexLoop(nex_listen_list);

}