Nextion & Arduino UNO don't communicate on Loop

[giorgio fossati]

Hello, my problem is when i connect arduino uno and nextion they don't comunicate ( ithink)
the strange fact is that i write.string on the setup and the value is displayed...
but when i press button nothing change ( on touch release event i printh 23 02 54 00)

1- the ground is in common (otherwise the value on startup won't be send and showed)
2- if i use the nextion simulator everything work fine ( the MCU respond and the nextion update the txt)
3- baudrate is the same
4- Rx led on arduino is always on ( ithink is right)

could be an hardware propblem of the nextion which can't send command on serial?
thanks for the help
here the code:
#include "EasyNextionLibrary.h"
EasyNex HMI(Serial);

float spd;

void setup() {
// put your setup code here, to run once:
//Serial.begin(9600);
HMI.begin(9600);
spd = 20;
String Spd = String(spd, 1);
HMI.writeStr("t0.txt", Spd);
}

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

}

void trigger0(){
//spd+=0.1;
spd=21;
String Spd = String(spd, 1); // Convert the float value to String, with 1 decimal place
HMI.writeStr("t0.txt", Spd);
}

void trigger1(){
//spd+=0.1;
spd=22;
String Spd = String(spd, 1); // Convert the float value to String, with 1 decimal place
HMI.writeStr("t0.txt", Spd);
}

void trigger2(){
//spd+=0.1;
spd=23;
String Spd = String(spd, 1); // Convert the float value to String, with 1 decimal place
HMI.writeStr("t0.txt", Spd);
}

void trigger3(){
//spd+=0.1;
spd=24;
String Spd = String(spd, 1); // Convert the float value to String, with 1 decimal place
HMI.writeStr("t0.txt", Spd);
}

[Leon]

Is the Arduino Uno connected to your PC with USB? I've noticed that I have issues with nextion devices if they're. Disconnect the USB and power is separately and it works.

[giorgio fossati]

Is the Arduino Uno connected to your PC with USB? I've noticed that I have issues with nextion devices if they're. Disconnect the USB and power is separately and it works.

thank for the reply...
No the arduino is disconnected from usb (since the uno have only one serial) and powerd separately with common GND with the nextion.
its driving me crazy, i think its a problem with the transmit of the nextion, becuase on void setup the ardu send the value to nextion and it show the string...but when i press the button on nextion nothing happen...
how i said with the simulator and ard connected to it everything work perfectly!

[Leon]

Have you confirmed that the system works with the code example? I too struggled for a couple of days tbh.

Edit: I just opened a ticket that sometimes I don't see that the trigger method is called: #53

[giorgio fossati]

Have you confirmed that the system works with the code example? I too struggled for a couple of days tbh.

Edit: I just opened a ticket that sometimes I don't see that the trigger method is called: #53

I tried with with two examble code:
1- ReadAndWriteNumber wich read the values fron nextion -> Didnt work
2- WriteTextAndCommands wich send commands to the nextion -> this one work perfectly
So the problem is with the trigger method of the library or with the Rx of the nextion???

[Leon]

Sending stuff to the Nextion seems to work perfectly but receiving from it doesn't. But also sending stuff isn't 100% accurate. I think it sometimes sends/receives a part of the data and then continues to the next loop. That's why sending a number works but sending a string or receiving the command doesn't.

[Athanasios Seitanis]

Try to rename the Spd String to tempSpd

String tempSpd = String(spd, 1); // Convert the float value to String, with 1 decimal place
HMI.writeStr("t0.txt", tempSpd);

Try to use a not float for spd in order to check if works

[giorgio fossati]

Try to rename the Spd String to tempSpd

String tempSpd = String(spd, 1); // Convert the float value to String, with 1 decimal place
HMI.writeStr("t0.txt", tempSpd);

Try to use a not float for spd in order to check if works

Hello, i will try that...but the problem persist also with your examples code:

I tried with with two examble code:
1- ReadAndWriteNumber wich read the values fron nextion -> Didnt work
2- WriteTextAndCommands wich send commands to the nextion -> this one work perfectly
So the problem is with the trigger method of the library or with the Rx of the nextion???

[Athanasios Seitanis]

Unfortunately, the activation method and library have been tested by me and many other users with no problems

[giorgio fossati]

Unfortunately, the activation method and library have been tested by me and many other users with no problems

So the problem could be be on my nextion device, a fulty one maybe?
I'm using the discovery series, you tested the examples on the basic series ?
meanwhile thank you !