How to get data that has line break before and after data

[jaydenpung]

Summary of Problem

I am having trouble getting the "data" event to trigger on SerialPort. Below is the "AT" command I sent, and the line break and "OK" I received:

If I understand correctly, using '@serialport/parser-readline' should be able to get the data (First data empty, second data "OK").

I can confirm the "AT" command is successfully sent, because when I stop the script and connect with putty, I can see a line break and "OK", and if I sent "ATTTTT\r\n" (invalid command), I can see "ERROR".

However, the on "data" event never seems to get triggered. I even tried changing the "\r\n" to buffer, but still no luck:
I have also tried various type of parser including InterByteTimeout at 3000ms with no luck

Code to Reproduce the Issue

const SerialPort = require('serialport')
const Readline = require('@serialport/parser-readline')
const port = new SerialPort('COM4')
port.on('open', () => {
    const parser = port.pipe(new Readline({ delimiter: '\r\n' }))
    parser.on('data', (data)=> {
        console.log(data)
    })
    port.write('AT\r\n')
})

Versions, Operating System and Hardware

• [email protected]
• Node.js v10.6.0
• Windows

[reconbot]

you might want to attach the parser before the port is open

[boraciner]

Try to do the following

port = new SerialPort(arg, { baudRate: 9600 }) const parser = new Readline() port.pipe(parser) parser.on('data', ProcessSerialInputBuffer) }); function ProcessSerialInputBuffer(buffer){ console.log("ProcessSerialInputBuffer",buffer) }