在节点serialport的文档中找到:

数据事件将端口置于流动模式。数据一收到就发出。数据是一个缓冲区对象,其中包含不同数量的数据。readLine解析器将数据转换为字符串行。有关解析器和节点的更多信息,请参阅解析器部分。有关数据事件的更多信息,请参阅js stream文档。

( https://github.com/EmergingTechnologyAdvisors/node-serialport/blob/5.0.0-beta8/README.md#module_serialport--SerialPort+event_data

这让你明白了这一点:

https://github.com/EmergingTechnologyAdvisors/node-serialport/blob/5.0.0-beta8/README.md#module_serialport--SerialPort.parsers )

默认解析器是以不同方式解析数据以转换传入数据的转换流。

文档示例:

实例

var SerialPort = require('serialport');
var Readline = SerialPort.parsers.Readline;
var port = new SerialPort('/dev/tty-usbserial1');
var parser = new Readline();
port.pipe(parser);
parser.on('data', console.log);
port.write('ROBOT PLEASE RESPOND\n');

// Creating the parser and piping can be shortened to
var parser = port.pipe(new Readline());

var SerialPort = require('serialport');
var ByteLength = SerialPort.parsers.ByteLength
var port = new SerialPort('/dev/tty-usbserial1');
var parser = port.pipe(new ByteLength({length: 8}));
parser.on('data', console.log);

要使用分隔符解析器,请提供一个分隔符作为字符串、缓冲区或字节数组:

var SerialPort = require('serialport');
var Delimiter = SerialPort.parsers.Delimiter;
var port = new SerialPort('/dev/tty-usbserial1');
var parser = port.pipe(new Delimiter({delimiter: Buffer.from('EOL')}));
parser.on('data', console.log);

要使用Readline解析器,请提供分隔符(默认为“\n”)

var SerialPort = require('serialport');
var Readline = SerialPort.parsers.Readline;
var port = new SerialPort('/dev/tty-usbserial1');
var parser = port.pipe(Readline({delimiter: '\r\n'}));
parser.on('data', console.log);

var SerialPort = require('serialport');
var Ready = SerialPort.parsers.Ready;
var port = new SerialPort('/dev/tty-usbserial1');
var parser = port.pipe(Ready({data: 'READY'}));
parser.on('data', console.log); // all data after READY is received