How to display nodejs raw Buffer data as Hex string

Question

The following code uses SerialPort module to listen to data from a bluetooth connection.

I am expecting to see a stream of data in Hexadecimal format printed in console. But the console just shows some weird simbols. I want to know how can I decode and display the data in console.

var serialPort = new SerialPort("/dev/tty.EV3-SerialPort", {
  parser: SP.parsers.raw
}, false); // this is the openImmediately flag [default is true]

serialPort.open(function () {
 console.log('open');
 serialPort.on('data', function(data) {
   var buff = new Buffer(data, 'utf8'); //no sure about this
  console.log('data received: ' + buff.toString());
 });  
});

data is already a buffer, no need to convert. Then: data.toString('hex'); — Laurent Perrin
– Laurent Perrin, Commented Sep 18, 2013 at 18:42

Justin · Accepted Answer · 2016-04-29 19:11:39Z

297

This code will show the data buffer as a hex string:

buff.toString('hex');

edited Apr 29, 2016 at 19:11

Justin

25.7k12 gold badges97 silver badges145 bronze badges

answered Jul 1, 2014 at 7:01

Seryh

3,3141 gold badge19 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

bubakazouba Over a year ago

do u know how to do the reverse?

Seryh Over a year ago

bubakazouba: new Buffer( buf.toString('hex'), 'hex' );

flob Over a year ago

[DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead. So now it should be Buffer.from( buf.toString('hex'),'hex');

Mamdouh Saeed Over a year ago

It returns for me [object ArrayBuffer]? what's wrong?

Alexis Wilke · Accepted Answer · 2018-11-29 20:57:11Z

3

Top answer is the simplest way to do it.

An alternative method:

data = Buffer.from([0x62, 0x75, 0x66, 0x66, 0x65, 0x72]);

Array.prototype.map.call(new Uint8Array(data),
               x => ('00' + x.toString(16)).slice(-2))
        .join('').match(/[a-fA-F0-9]{2}/g).reverse().join('');

edited Nov 29, 2018 at 20:57

Alexis Wilke

21.2k11 gold badges111 silver badges183 bronze badges

answered Jul 25, 2017 at 19:45

Omar Taylor

1434 bronze badges

1 Comment

Edza Over a year ago

This answer was actually useful for me, because I have to join it with '-' for it to interop with C#. Upvoted.

Collectives™ on Stack Overflow

How to display nodejs raw Buffer data as Hex string

2 Answers 2

4 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related