UDP Send/recieve to non MAX objects

Hi Brett,

I had a similar problem to yours a while ago (although not exactly the same problem):

https://cycling74.com/forums/using-raw-binary-data-in-a-patch

After reading about the suggested FullPacket message and actually after making some tests with udpsend and an (external) udp receiver command-line tool I just had the impression that udpsend is sending (and respectively, udpreceive is expecting) data in an OSC-formatted way. Therefore (at least as far as I noticed) you should send your data in OSC format. This might cause the trouble when you send from C# to Max.

The other direction (Max->C#), I can't really understand. Are you sure there's no other object or software listening on the same UDP port that the one you try to use for the Max->C# communication? Just because if there would be another udp listener thread bound to the same port (like an udpreceive in Max), it might happen that it would receive your udp messages instead of the C# listener.

Actually I developed a couple of objects (still unpublished as I still didn't find my time to write a proper help file and documentation) that make possible raw binary communication via TCP and UDP between Max and the 'rest of the world'. Let me know if you're interested.

Cheers,
Ádám

Hello,

Thank you for the pointer.

After doing a bit more digging around i figured out that:
1) I missunderstood how to setup UDPSend. It turns out that I made a function "udpsend localhost 11100" but just doing a bang on that device did not work. Once I hooked up and sent in a message "port 11100" I saw the debug show that it bound to that port.

2) Yup, i found out that I have to look at the OSC format but I think for what i'm doing right now I'll be OK without using the OSC format (Max->C#).

I'll see how far I get with my current path over the next day or two. If I need the code after that I'll let you know.

In one repect I'm surprised I can turn off the OSC format and just send raw UDP data.

Thanks for the help,
Brett

Hello Siska,

I am actually working on a project needing to receive raw UDP data.
I want to receive data from motion capture:
http://www.xsens.com/en/general/mvn

These data are not OSC format.

When I use the udpreceive object using the OSC-full-packet-designation (I put "foo" as symbol), I get messages like this in the MAX window:
Fullpacket 664 75947888
But I don't know if I can get the full message, and how...

If I remove the symbol, I get the messages:
OSC expected type string. Dropping message for address MXTP03.

So I think the objects you developped to read/write binary data would be very usefull for me!

Could you share them? I would be very grateful, because I am new to max, and have very few time to do this.
Perhaps I will could help for the documentation?

Thanks,
Sophie

Hi Sophie,

You should check out [mxj net.udp.send] and [mxj net.udp.recv]. You'll find some other java networking objects from there.

best,
Zachary

Hi Zachary,

Thanks a lot for your quick response. I tried [mxj net.udp.recv].
It seems to work: I receive the UDP messages from moven. The [print] gives me:
MXTP03

But I don't know how to get the full message? I guess I must develop a new mxj class?

I was watching at the recv class, and I see that it uses Atom objects:

private void receiver(Atom[] a) {
        outlet(0, a);
    }

So my idea is to create a new java class and try to override this method to parse the Atom[] received.
Do you confirm this is the good way to do it?

Thanks,
sophie

I too would love to be able to receive the full, raw UDP packet rather than having to format in OSC. Are we saying this is possible?

@Siska Adam, do your objects allow this?

Thanks

if you want to build an mxj class for sending/receiving raw udp packets, this might be helpful:
http://www.esbasel.ch/Downloads/UdpSend+RecvRaw.zip

it served me as a starting point for talking to various micro controllers.
volker.

Thanks a lot Volker, I think this is effectively a very good starting point for me too!
Scatalogic, I think this will help you too.

Volker,
I have some questions about you code, cause I don't get all UDP messages.
I just created a simple test, with an object:
[mxj UdpRecvRaw @port 7777]
and I put the output in a [print]

I try to get data from moven, which is streaming on port 7777 with a frequency of 60Hz.

Some times I get some data, but not every time... for example, now if I retry I have nothing. Should I initiate the UdpRecvRaw (with a bang, or something)? How do you use it in max exactly?

did you have a look at the help file, does that work for you?
this is really just a very stripped down version for demonstration, and not very useful like it is in real life.
the outlet of the UdpRecvRaw simply sends a bang, when a packet is received.
also, the received byte array is not handed over to max, but simply printed to the max window.
if you want to pass the packets to max, you'll have to extend the java class a little.
for my purposes, i found it easier to deal with the data in java.

if you send a stop message to the object, the socket is closed, and you can't open it again... not very elegant, but this was also for the sake of simplicity.

and yes, 60 Hz sounds like a pretty dense stream...