How to Use Nextion display: Examples, Pinouts, and Specs

The Nextion display is a smart display module that integrates a touchscreen interface with a built-in microcontroller. It is designed to simplify the process of creating graphical user interfaces (GUIs) for embedded systems. By offloading the GUI processing to the display itself, the Nextion module reduces the workload on the host microcontroller or microprocessor.

Nextion displays are widely used in applications such as:

• Home automation systems
• Industrial control panels
• IoT devices
• Medical equipment
• Automotive dashboards
• Consumer electronics

With its user-friendly Nextion Editor software, developers can design and program GUIs without requiring advanced programming skills.

Below are the key technical details for the Nextion display (specific values may vary depending on the model):

The Nextion display typically has a 4-pin interface for communication and power:

To use the Nextion display with an Arduino UNO, follow these steps:

1. Wiring:

   • Connect the VCC pin of the Nextion display to the 5V pin on the Arduino.
   • Connect the GND pin of the Nextion display to the GND pin on the Arduino.
   • Connect the TX pin of the Nextion display to the Arduino's digital pin 2 (via a voltage divider if required).
   • Connect the RX pin of the Nextion display to the Arduino's digital pin 3.

2. Install the Nextion Library:

   • Download and install the official Nextion library from the Arduino IDE Library Manager.

3. Design the GUI:

   • Use the Nextion Editor software to design your GUI. Upload the .tft file to the display using a microSD card.

4. Arduino Code Example: Below is an example code snippet to display a message on the Nextion display:

   #include <Nextion.h>
   
   // Define Nextion objects (page ID, component ID, component name)
   NexText t0 = NexText(0, 1, "t0"); // Textbox on page 0, ID 1, named "t0"
   
   // Define software serial for communication
   #include <SoftwareSerial.h>
   SoftwareSerial nextion(2, 3); // RX, TX
   
   void setup() {
     // Initialize serial communication with Nextion
     nextion.begin(9600);
     Serial.begin(9600);
   
     // Initialize the Nextion library
     nexInit();
   
     // Set initial text on the display
     t0.setText("Hello, Nextion!");
   }
   
   void loop() {
     // Handle any incoming events from the Nextion display
     nexLoop(nex_listen_list);
   }
   

   Note: Ensure the baud rate in the Nextion Editor matches the baud rate in the Arduino code.

• Power Supply: Use a stable power source to avoid display flickering or unexpected resets.
• Voltage Levels: Ensure the UART communication voltage levels match (3.3V or 5V). Use a voltage divider or level shifter if necessary.
• GUI Design: Optimize your GUI design to minimize memory usage and improve performance.
• Debugging: Use the Nextion Editor's simulator to test your GUI before uploading it to the hardware.

1. Display Not Powering On:

   • Verify the power supply voltage and current are within the specified range.
   • Check the wiring connections for loose or incorrect connections.

2. No Communication Between Arduino and Nextion:

   • Ensure the TX and RX pins are correctly connected.
   • Verify the baud rate in the Arduino code matches the Nextion display settings.
   • Check for proper grounding between the Arduino and the Nextion display.

3. GUI Not Displaying Correctly:

   • Confirm the .tft file was uploaded correctly to the display via the microSD card.
   • Ensure the GUI design is compatible with the display's resolution.

4. Touchscreen Not Responding:

   • Check if the touchscreen type (resistive or capacitive) matches your expectations.
   • Verify the GUI design includes touch-enabled components.

Q: Can I use the Nextion display with other microcontrollers?
A: Yes, the Nextion display can be used with any microcontroller or microprocessor that supports UART communication, such as ESP32, Raspberry Pi, or STM32.

Q: How do I update the firmware on the Nextion display?
A: Use the Nextion Editor to generate a .tft file and upload it to the display via a microSD card.

Q: Can I use multiple Nextion displays in a single project?
A: Yes, you can use multiple displays by connecting them to separate UART ports or using a multiplexer.

Q: Is the Nextion Editor software free?
A: Yes, the Nextion Editor is free to download and use for designing GUIs.