Nextion-InstructionSet

This library is based on the library by gregory-yet. It sends and receives data via a UART connection with a Nextion display.

Installation

npm i nextion-instructionset

Dependencies

SerialPort

Note

• If you use an raspberry pi make sure to correctly enable serial port connections. For more information take a look in the docs
• Always ensure that the nextion display is connected correctly to avoid irreparable damage to the display.

Getting started

Set the port and baudrate for your application accordingly

const Nextion = require('nextion-instructionset');
const port = '/dev/ttyS0';
const baudrate = 9600;
const nextion = new Nextion.init(port, baudrate);

nextion.on('connected', function() {
    console.log("display connection established");
});

Send data

Send data by using the write class

uart

Sends an uart command to the nextion display Take a look at the official nextion instruction set to see every supported command

/**
 * @param {string} command
 */
nextion.write.writeUart('page 0');

setPage

Changes the page to the corresponding page id

/**
 * @param {number} page number
 */
nextion.write.setPage(0);

setText

Sets the text of a text field

/**
 * @param {string} component reference 
 * @param {string} text
 */
nextion.write.setText('t0', "Test");

setVis

Sets the visibility of a component

/**
 * @param {string} component reference
 * @param {boolean} active/ deactive
 */
nextion.write.setVis('t0', false);

drawCircle

Draws the outline of a circle

/**
 * @param {number} x pos
 * @param {number} y pos
 * @param {number} radius
 * @param {string} color -> use the color enum
 */
nextion.write.drawCircle(100, 100, 50, Nextion.color.red);

drawCircleFilled

Draws a filled circle

/**
 * @param {number} x pos
 * @param {number} y pos
 * @param {number} radius
 * @param {string} color -> use the color enum
 */
nextion.write.drawCircleFilled(100, 100, 50, Nextion.color.red);

drawRect

Draws a custom rectangle outline at a given position

/**
* @param {number} x pos
* @param {number} y pos
* @param {number} width
* @param {number} height
* @param {string} color -> use the color enum
*/
nextion.write.drawRect(100, 100, 50, 50, Nextion.color.red);

drawRectFilled

Draws a custom rectangle with a solid color at a given position

/**
* @param {number} x pos
* @param {number} y pos
* @param {number} width
* @param {number} height
* @param {string} color -> use the color enum
*/
nextion.write.drawRectFilled(100, 100, 50, 50, Nextion.color.red);

drawLine

Draws a line from the first to the second position

/**
* @param {number} x1 start pos
* @param {number} y1 start pos
* @param {number} x2 end pos
* @param {number} y2 end pos
* @param {string} color -> use the color enum
*/
nextion.write.drawLine(50, 50, 100, 100, Nextion.color.red);

setBackgroundColor

Sets the background color of a component that has an adjustable background color

/**
 * @param {*} component reference
 * @param {*} color -> use the color enum
 */
 nextion.write.setBackgroundColor('t0', Nextion.color.red);

clearScreen

Clears the screen and fills it entirely with a specified color

/**
 * @param {*} color -> use the color enum
 */
 nextion.write.clearScreen(Nextion.color.white);

clickBtn

Clicks the button with the corresponding component reference

/**
 * @param {string} button reference
 */
nextion.write.clickBtn('b0');

reset

Resets the nextion display and forces an immediate reboot

/**
 * @param {string} button reference
 */
nextion.write.reset();

Colors

Use the color enum with either the preset color attributes or by using the rgb/ hex function

Nextion.color.black;
Nextion.color.blue;
Nextion.color.brown;
Nextion.color.green;
Nextion.color.yellow;
Nextion.color.red;
Nextion.color.gray;
Nextion.color.white;

/**
 * @param {number} r 
 * @param {number} g 
 * @param {number} b 
 */
Nextion.color.rgb(29, 161, 222);

/**
 * @param {string} hex
 */
Nextion.color.hex('#1da1de');

Events

Subscribe to events to know when something on the display was changed

// the connection to the nextion display was established
nextion.on('connected', function() {
});

// the connection to the nextion display was closed
nextion.on('close', function() {
});

// the display user touched the display
nextion.on('touchEvent', event => {
    console.log("touchEvent occured on page: " + event.page + " by component id: " + event.id + " with the state: " + event.state);
});

// the page on the display changed
nextion.on('pageChanged', page => {
    console.log("page changed: " + page);
});

// the display send data
nextion.on('receivedData', data => {
    console.log("receivedData: " + data)
});

// an error occured with the uart connection
nextion.on('error', error => {
    console.log('An error occured with the nextion connection: ' + error);
});