@bulletlogic/socket.io-serialport
v2.1.0
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Expose a serial port over a socket.io instance
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socket.io-serialport
Expose a serial port over a socket.io instance. Particular thanks go to the serialport, socket.io-stream and hterm projects.
Usage
npm install --save socket.io
npm install --save socket.io-serialport
Then to connect to a serial port and open it (note that the options
field is passed directly to the serialport
instance, however the autoOpen
option will always be forced to false)
const Server = require('socket.io');
const SerialPort = require('socket.io-serialport');
const io = new Server(8080);
const serialport = new SerialPort({
io: io,
route: '/port/ttyS0',
captureFile: '/var/log/serialport/ttyS0',
retryPeriod: 1000,
device: '/dev/ttyS0',
options: {
baudrate: 115200
}
});
serialport.open()
.then(() => {
console.log('port opened');
// And when done (shutting down, etc)
serialport.close()
.then(() => {
console.log('port closed');
});
});
Then connect socket.io
clients to the following endpoint
var io = require('socket.io-client');
var ttyS0 = io('http://localhost:8080/port/ttyS0');
with the socket.io
instance you can just use data
events
// listen for data from the serial port
ttyS0.on('data', function(data) {
console.log(data);
});
// Send some data to the serial port
ttyS0.emit('data', 'pwd\n');
Or connect socket.io-stream
clients to use streams
// Create a duplex stream
var ttyS0Stream = ss.createStream();
// listen for data from the serial port
ttyS0Stream.on('data', function(data) {
console.log(data);
});
// Notify the server with a `stream` event to setup
// a duplex stream at the other end which will
// pipe to and from the serial port
ss(ttyS0).emit('stream', ttyS0Stream);
// Send some data to the serial port
ttyS0Stream.write('pwd\n');
or both :)
Handling serial port disconnects, etc
Events will be emitted when the state of the remote serial port changes. You can use these events to notify a user, etc.
Also on initial connection of the socket an event should be received giving the current status of the port.
ttyS0.on('status', function(status) {
console.log(status);
});
where status
will be one of
{status: 'open'}
- the port is open{status: 'closing'}
- the port is closing after calling#close
{status: 'closed'}
- the port is closed after calling#close
{status: 'disconnected', error: error}
- the port disconnected and should be reopened after theretryPeriod
{status: 'opening', error: error}
- the port is opening, theerror
field will be set if it is reopening after an error