Danny's Digital Voice

A alternative digital voice system for the modern world of amateur/ham radio. Uses GMSK modulation at 9600 bits/s using the Speex/Codec2 codec.

This is currently under development and experimentation - as I need to perfect my GMSK modem first (used for my DDP project). The circuit for the modem will also be released, features so far: RS-232 interface, direct connection to your rig using 9600 baud data connection. Uses standard "of the shelf" components, currently no PICs are used.

Status: Alpha

Supported OS: FreeBSD, Linux, and other Unix-like OS'es

Supported Hardware: Any modem (custom built or commercial) interfaced to your PC via RS-232 which can connect to your transceiver at 9600 baud

Technology Backend: DDP (>= v0.6.0)

Don't forget to download

• (All) 7zip - To extract the files from the archive.

My other projects

• (All) DDP - My own protocol designed to replace the aging packet system using cheap off-shelf-equipment (no TNCs needed). Uses fldigi as it's "starting point".
• (All) StormForce XR - Real-time lightning detection for your desktop using Boltek products.

News

11th February 2012 - News

• Made changes required to make DDV work with DDP v0.6.0.

• DDP v0.5.4 has been released, no code changes were required for DDV.

• DDP v0.5.3 has been released, no code changes were required for DDV.

• Join me here on Google Plus for ham/electronics-related topics!

• With Codec2 now running at 1400bit/s, it should be possible to run it over my AFSK modem running at 1800 baud (MX614 IC) - wonder if the 1200 bit/s port on the rig is able to run a little faster? Hmmm, thinking DV over SSB on my trusty Yaesu FT-817.

• Made a few changes required to make DDV work with DDP v0.5.2.

• Made a few changes required to make DDV work with DDP v0.5.1.

• Made a few changes required to make DDV work with DDP v0.4.2.

• Just made a few changes required to make DDV work with DDP v0.4.1.

• I'm going to look at using the AMBE codec via the DVDongle to provide an additional codec available to DDV. No-one has done any tools for the DVDongle wrote in Python so I'll have to do it myself - nothing new then, hi.

• It's been in development for several months now but the first release of DDV is now available. It's a bit rough on the edges but it's time for its release. DDV requires DDP v0.4.0 or higher to function.

• Managed to sort out the timing issue with DDV completely. Just needs additional testing and tidying up.

• Still making the changes to DDP for DDV, managed to reduce the timing issue by half but still needs reducing further...

• Getting the first release of DDV is taking longer than I expected, locating a timing issue which is causing the required baudrate to increase at 2x fold (maybe more, 4x)... Bare with me!
• On a side note, I've made a RS-232 modem which uses a laser as it's transmission medium. Got it working upto 115200 baud without any problems.

• Making some progress with DDV, maybe able to get something released in about a week. Watch this space!

• Been working on DDV today, made some progress. DDV will use DDP as it's transport so it will have all the features and reliability of DDP.
• Codec2 looks promising as well, DDV will also support this codec.

• I've also started playing with Codec2 which I've managed to get compiled on FreeBSD, I've sent Dave VK5DGR what I did to do this.

• The GMSK modem is now decoding packets. Just fine tuning the RX section...

• Left the modem for a while doing over projects, had another whirl today but still can't it to decode the GMSK signal. Adjusting the DC bias on the RX input changes the data output so I know it's doing something. Maybe the TX needs biasing as well? Hmmm...

• It appears the CMX589 needs a bias on the audio input, but can't get it decode yet...

• Project created on Google Code
• Project concept begun