How to Get DDP Running on my Mac?

[Chuck]

Mr. Knapps,

I would like to try to install DDP on my Mac, but it is written in Python and I have no idea how to install DDP and make it work with fldigi.  I know my Mac has Python (Python 2.6.1).  None of the information on DDP tells me how I can use it with fldigi and which of the examples (if any) I need to use to be able to get fldigi to send and receive packets to talk via digipeaters and/or nodes to chat, pbbs, etc.  

Wading though the Python code is not high on my list of  things to do because I am trying to get all of my packet software running on my Mac using a Signalink USB sound card to be ready for ARES.  I have fldigi and its associated services running except flrig (only have a dual band 2m/70cm radio and my rig not a supported).  In addition, I am running Parallels with WinXP to do Winlink 2000 via RMS Express, AGWPE, and Winpack, but I would rather use my Mac side to do packet communications.  Unfortunately cocoaModem or MultiMode do not do packets and Xastir works fine with APRS, but not packet communications.

I am hoping you can provide me guidance on how to get DDP to run with fldigi on my Mac (which runs on top of a scaled down Linux).  Your assistance is greatly appreciated.

73, Chuck Burton K9CBX

[Danny Knaggs]

Hi Chuck,

Sorry for the delay in replying, been very busy with work.

I'm not sure where to start with getting DDP running on a mac.  First of all, get fldigi working with the Signalink USB - should be pretty easy and will pretty much take care of the rig side.  Have a few QSOs to ensure PSK works fine.

You might be able to use MacPorts which is essentially the same as FreeBSD ports.  I don't know exactly how it works but you should find all the ports I mention in the readme file.  You only need two dependencies apart from python - py-serial and py-m2crypto.


DDP is it's own packet protocol, it is designed to replace the existing packet system - not work with it or even be compatible (never will be).  Just be aware of this.



73,


Dan.

[Chuck]

Dan,

Finally figured out the socket problem and got everything to "compile" without error.  Now it is unclear to me what Operational Mode you need to use with fldigi to get your code to work with fldigi.  Looking at the Python code, it appears that you are specifying PSK500R as the data mode to be used by fldigi.  However, in the code specified data mode, fldigi just receives a continuous stream of garbage characters when not sending anything and the fldigi waterfall diagram shows no signal.  That makes it difficult to find received messages in the clutter.

When using im_chat,py, it seems as though you have to be attached directly to the individual rather than using a digi or node.  Thus, I assume one would have to edit the code to create the route needed to perform a distant chat.

I have pretty much answered my own questions except:  Is the DDP protocol compatible with the PBBS, packet email, packet chat, etc. systems?  Since I am running VHF/UHF, is there a mechanism to allow me to use FM rather than PSK?

73, Chuck

[Danny Knaggs]

"

Looking at the Python code, it appears that you are specifying PSK500R as the data mode to be used by fldigi"

These can be changed in the settings XML file.  You can pretty much any mode fldigi offers - but I'd stick with PSK/MFSK.

"However, in the code specified data mode, fldigi just receives a continuous stream of garbage characters when not sending anything and the fldigi waterfall diagram shows no signal"

Receiving random characters in the waterfall while receiving no "real" data is perfectly normal.

"That makes it difficult to find received messages in the clutter"

DDP will find the packet, as long as fldigi can decode the underlying modulation.

"When using im_chat,py, it seems as though you have to be attached directly to the individual rather than using a digi or node"
Correct, that's how that specific example works.

"Is the DDP protocol compatible with the PBBS, packet email, packet chat, etc. systems?"
No - never will do, DDP is aiming to replace it.  My examples give you some of the features of the old packet system plus many more.

"Since I am running VHF/UHF, is there a mechanism to allow me to use FM rather than PSK?"
You can use any mode AM, FM, SSB, etc for transmitting the audio - in this case PSK - all the modes in fldigi are designed for SSB but there's no harm in trying others.  FM will be fine.  But it's better to use SSB if your rig supports this.


Hope this has helped.


Dan.