Wednesday, December 7, 2016



The port of the MMDVM code to the STM32F4 series has taken a major leap forward
As per Jim's email to the MMDVM Yahoo group late last night
Does that guy ever sleep :-)

All the source code is already waiting on github. Andy posted the modified Standard Peripheral Drivers in the Files section of the MMDVM Yahoo group. I just posted a text document detailing how to build the code and program the boards.

To start we have support for the STM32F407 Discovery board and the STM32F446 Nucleo board.

I'm attaching a picture of Andy's setup. He's got it working well on DMR. You can also see that he's included the TCXO board for a more accurate clock. I've been doing my testing on DStar.

The instructions include details for building under Windows, OSX and Linux using gcc. There is also limited support for building the code under CooCox (Win32).


Saturday, November 19, 2016

Mid-November update


Mid-November update


After a few long months of designing, testing and fine tuning, we finally have some concrete things to share with you guys. It might not be exactly the kind of news you were expecting, but we’re confident you won’t be disappointed...

Despite our best efforts, the MMDVM revision 1.2 is still far from completion.

The design we originally envisioned for 1.2 incorporates a really good filter, but it is quite “aggressive” and requires more work, a lot more than we anticipated, both in software and hardware.

You probably noticed the messages some of our rev 1.2 testers exchanged on the Yahoo group over the last few months … We tested and tweaked, and then tested some more but unfortunately it’s just not ready.


A big “Thank you!” goes to all those who helped us design and test this board. We owe you a beer! (or five?!)

We’ll continue to work on the MMDVM revision 1.2 boards, and we hope we’ll find a solution

In the meantime, as a small and well deserved reward for your patience, we’d like to present you a new board: the Rev 1.0.1 board.

We designed the new Rev 1.0.1 board with the following features:

  • 12Mhz TCXO
  • Multi-turn pots
  • RSSI Inputs
  • I2C output (to connect LCD)
  • A serial output (to connect LCD)
  • Additional radio sense and control lines to be used for DR1X conversation
  • Protection diodes on all the radio signals
  • Additional Status LEDs
The PCBs are ready and they’re heading to the CM. However, it is mid-November and the timing is not really great. As the holiday season approaches fast, the deadlines become really fluid… We’d love to tell you that we’ll ship them in 2-3 week but we simply don’t know.
Our best guess is: “December”…
 
Once we get into production we will off course be releasing the schematics (PDF)

Saturday, October 8, 2016

Over the last couple of months we have been struggling to get the MMDVM Rev 1.2 into your hands.
We’ve hit a few roadblocks and that put us behind the original schedule. 

The first batch of boards was ready about a month ago, but unfortunately we had to scrap them due to a manufacturing error. Thankfully, it was just a test run …

We are confident that we’re on the right track this time and we think the first boards will hit the post office mid-November.

We’re sorry about the delays but we don’t want to compromise on the quality of the product. We’ve never failed you in the past and we’re not about to start now.

If you no longer wish to wait for the MMDVM Rev 1.2, we understand and we’d like to ask you to contact Bruce to remove your name from the waiting list.

Thank you for your patience,

The ZUM MMDVM Team

Thursday, August 25, 2016

A very interesting update from Jonathan posted on the facebook page 8/25/2016

After some investigating by some very clever people, it appears that a simplex (DMO mode) DMR system is possible without having to use radios with very fast TX/RX changeover times. Therefore I have started work on such a mode for the MMDVM. This would potentially allow for a tri-mode simplex gateway since D-Star and C4FM already allow for simplex use.
This will use exactly the same hardware as a duplex MMDVM, the same interface boards for example, but with only one FM transceiver instead of two, and of course no need for a duplexer.
I hope to get the first versions available next week. See the MMDVM Yahoo! group for more details.

Tuesday, August 16, 2016

Thursday, August 4, 2016

We’re back with a little update.

Sorry about keeping you in the dark. You know how it is: the family and a full-time jobs leaves us very little time for hobbies. Not to mention the irresistible nice weather (at least up here in Canada)…

That being said, we’re a little bit behind the schedule with the new boards but we’re moving in the right direction.

First of all, the unreleased revision 1.1 that we mentioned at the Dayton Hamvention this year got so many improvements that we decided to launch it as revision 1.2. The change in name won’t affect the end users, but it helps us keep track of the things we do.

Here’s what kept us busy all this time:

•             PCB change from 2 layers to 4 layers (New internal layers for 3.3V and GND)
•             New filters and amps (designed by EB4FBZ)
•             Improved routing of traces
•             Added protection diodes to all external pins
•             Adding one more op-amp in both transmit and receive paths for new filters
•             Added one more radio status and one more control line
•             Added two more status LEDs
•             Added circuitry for both TCXO and crystal for low ppm clock (the boards will ship with TCXO)
•             Corrected long standing connector spacing problem
•             Changed from 270 degree turn trimmers to multi-turn trimmers
•             Changed critical paths to higher quality resistors and capacitors
•             Added solderable jumpers to bypass large bypass capacitors
•             Added external RSSI input connector - goes to ADC pin on Due

Thank you for your patience and continuous support!

Friday, May 20, 2016

Press Release :: MMDVM V1.1 · Better filtering. Integrated clock. Extended connector

We are proud to announce the impending release of the KI6ZUM Zum MMDVM Rev 1.1 board

Features of the new board include: improved filtering by EB4FBZ, integrated clock, new 8 pin connector for additional control lines.

As this board is still a few weeks away and we don’t want to disrupt the amazing things that our fellow hams are doing with the current board, we will be continuing to supply the MMDVM Rev 1.0 boards at a special price of $35.00.

If you already ordered the MMDVM Rev 1.0 board, but instead, you'd like to wait a little longer for the MMDVM Rev 1.1 board, please contact Bruce to inform him about the change as soon as possible. 

If you want to take a look at the new boards, you have a chance to do so at Dayton Hamvention where Guus has graciously allowed us some space at the DVMega booth EH0519.

Thank you for your continuous support,
The MMDVM Team

Wednesday, May 18, 2016

Very cool
First C4FM QSO on VK4TUX mmdvm YSF Reflector


Friday, May 6, 2016

A great Video from Richard on using the MMDVM with the DR1X repeater making it trilingual... D-Star, DMR and Fusion