+5V = 5V
  TX  = pin 0 (RX)
  RX  = pin 1 (TX)
  GND = GND

#include <Nextion.h>
// Include the nextion library (the official one) https://github.com/itead/ITEADLIB_Arduino_Nextion
// Make sure you edit the NexConfig.h file on the library folder to set the correct serial port for the display.
// By default it's set to Serial1, which most arduino boards don't have.
// Change "#define nexSerial Serial1" to "#define nexSerial Serial" if you are using arduino uno, nano, etc.

int variable1 = 0;  // Create a variable to have a counter going up by one on each cycle
int counter = 0;  // Create a variable to have a counter for the + and - buttons
int CurrentPage = 0;  // Create a variable to store which page is currently loaded

// Declare objects that we are going to read from the display. This includes buttons, sliders, text boxes, etc:
// Format: <type of object> <object name> = <type of object>(<page id>, <object id>, "<object name>");
/* ***** Types of objects:
   NexButton - Button
   NexDSButton - Dual-state Button
   NexHotspot - Hotspot, that is like an invisible button
   NexCheckbox - Checkbox
   NexRadio - "Radio" checkbox, that it's exactly like the checkbox but with a rounded shape
   NexSlider - Slider
   NexGauge - Gauge
   NexProgressBar - Progress Bar
   NexText - Text box
   NexScrolltext - Scroll text box
   NexNumber - Number box
   NexVariable - Variable inside the nextion display
   NexPage - Page touch event
   NexGpio - To use the Expansion Board add-on for Enhanced Nextion displays
   NexRtc - To use the real time clock for Enhanced Nextion displays
 * *****
*/
NexText t0 = NexText(0, 1, "t0");  // Text box added, so we can read it
NexText t1 = NexText(0, 2, "t1");  // Text box added, so we can read it
NexNumber n0 = NexNumber(0, 3, "n0");
NexNumber n1 = NexNumber(0, 4, "n1");
// Declare pages:
// Sending data to the display to nonexistent objects on the current page creates an error code sent by the display.
// Any error sent by the display creates lag on the arduino loop because arduino tries to read it, thinking it's a touch event.
// So to avoid this, I am only going to send data depending on the page the display is on.
// That's the reason I want the arduino to know which page is loaded on the display.
// To let arduino know what page is currently loaded, we are creating a touch event for each page.
// On the nextion project, each page most send a simulated "Touch Press Event" in the "Preinitialize Event" section so
// we can register that a new page was loaded.
NexPage page0 = NexPage(0, 0, "page0");  // Page added as a touch event
// End of declaring objects

char buffer[100] = {0};  // This is needed only if you are going to receive a text from the display. You can remove it otherwise.
// Further on this sketch I do receive text so that's why I created this buffer.
// Declare touch event objects to the touch event list:
// You just need to add the names of the objects that send a touch event.
// Format: &<object name>,

NexTouch *nex_listen_list[] = {
    &page0,  // Page added as a touch event
    &t0,
    &t1,
    &n0,
    &n1,
    NULL  // String terminated
};  // End of touch event list

void setup()
{
    nexInit();// Put your setup code here, to run once:
    Serial.begin(9600);  // Start serial comunication at baud=9600
    pinMode(13, OUTPUT);
    // I am going to change the Serial baud to a faster rate.
    // The reason is that the slider have a glitch when we try to read it's value.
    // One way to solve it was to increase the speed of the serial port.
    delay(500);  // This dalay is just in case the nextion display didn't start yet, to be sure it will receive the following command.
    Serial.print("baud=115200");  // Set new baud rate of nextion to 115200, but it's temporal. Next time nextion is power on,
    // it will retore to default baud of 9600.
    // To take effect, make sure to reboot the arduino (reseting arduino is not enough).
    // If you want to change the default baud, send the command as "bauds=115200", instead of "baud=115200".
    // If you change the default baud, everytime the nextion is power ON is going to have that baud rate, and
    // would not be necessery to set the baud on the setup anymore.
    Serial.write(0xff);  // We always have to send this three lines after each command sent to nextion.
    Serial.write(0xff);
    Serial.write(0xff);
    Serial.end();  // End the serial comunication of baud=9600
    pinMode(13, OUTPUT);
    Serial.begin(115200);  // Start serial comunication at baud=115200
    // Register the event callback functions of each touch event:
    // You need to register press events and release events seperatly.
    // Format for press events: <object name>.attachPush(<object name>PushCallback);
    // Format for release events: <object name>.attachPop(<object name>PopCallback);


}  // End of setup
int v = 0;
int incomingByte = 0;
const int n11 = 0;
void loop()    // Put your main code here, to run repeatedly:
{
    nexLoop(nex_listen_list);  // Check for any touch event0
    uint32_t number1 = 0;  // Create variable to store value of slider
    n1.getValue(&number1);  // Read the value of the slider

    if(v == 99) {
        v = 0;
    }

    if(Serial.available() > 0) {
        // read the incoming byte:
        incomingByte = Serial.read();
    }

    if(incomingByte == 0) {
        v++;
    } else {
        v = 98;
        v--;
    }

    Serial.print("n0.val=");
    Serial.print(v);
//  n1.setValue(&number1);
    Serial.write(0xff);
    Serial.write(0xff);
    Serial.write(0xff);
}  // End of loop