All about the DV4home

[iball]

User manual finally released weeks after shipping the product to consumers.

My thoughts on it here:

https://www.reddit.com/r/amateurradio/comments/54c8mx/dv4home_user_manual_finally_released/

 

[iball]

UPDATE: The most recent software update (0.065) to the DV4home now has the DMR+ server in Naples, FL hardcoded into the dmr program itself so it can not be changed by the normal user.
It no longer pulls the DMR_MASTER_IP from the config.cfg or config.db file.
If that server ever goes offline, the device becomes unable to do DMR at all.
It's easy enough to hex-edit the dmr program file itself to change the hardcoded IP address to a Brandmeister master server - I've done it as a proof-of-concept - which causes me to really question why they hardcoded the IP address in there in the first place unless it's to make it impossible for the average amateur radio operator to ever be able to change it as an effort to block it from working on Brandmeister.

Also, there is a second IP address hardcoded into the dmr program that routes back to a port on a router at the Hamburg University of Applied Sciences.
I have no idea what the affiliation between the University in Hamburg and Wireless Holdings in Naples, Florida actually is, or why the DV4home would be talking to something at the University.

 

[EricCottrell]

Have created disk image of the original 4GB micro-SD that runs this box.
Copied it over to an old 8GB micro-SD I had laying around.
Now I have some breathing room on the newer, fast card..
Ran apt-get update and discovered over 400 packages that required updating.
Woah. That's one really old Linux distro.
"apt-get upgrade"
(20 minutes pass...)

There. Now everything's up-to-date. Unit still boots into their software and works fine.
But now it's not full of potential security holes.

Now to work on getting newer, better software to work on this thing like ircddbgateway, MMDVMHost, etc.
Will probably require modification to a lot of source code to get it to work with the AMBE3000R chips on the daughtercard.

Hello,

What is the codec used by the newer software that needs to be changed?

I have done work with the USB version of the AMBE3000 and did not find it too difficult to communicate with it. The USB version uses serial packets.

73 Eric

 

[iball]

This box runs two programs - DV4AMBE_1 & DV4AMBE_2 - that run on /dev/ttyS1 and /dev/ttyS2 respectively that decode/encode everything via those serial ports so it looks like it's some sort of custom AMBEserver, probably from the OpenDV repo itself (DV3000/DummyRepeater?). Those are probably talking to the two AMBE chips on the daughtercard in this thing.
The trick is to get some sort of middleware virtual modem running that points to one or more of those serial ports that MMDVMHost can talk to.
Honestly, been busy with work and haven't played too much around with it other than hex-editing the latest dmr program inside the 0.065A software update to point it to the BMDEV master server instead of that DMR+ server in Naples, Florida, editing the HTML code to include linking to reflector 4999 on BM, and using the BM extended routing dashboard to select a talkgroup.
It's only got 128MB of RAM which should be more than enough to do what I want, it's just that compiling on this Foxboard - even with a much faster 8GB micro-SD card - is so slow.
MMDVMHost compiles and runs just fine on it, it just doesn't see a DVMega modem.

 

[EricCottrell]

Hello,

That is a good clue pointing to the software using the Serial UART Interface.
http://www.dvsinc.com/manuals/AMBE-3000_manual.pdf

I wonder if they are using two AMBE chips so it can decode both slots of DMR at the same time.

I did something similar on the receive side by replacing the mbelib part of dsd with a driver for the USB3000. The USB3000 looks like a serial port and uses the same UART format.

The DV4AMBE_1 and DV4AMBE_2 programs handle the initialization and configuration of the AMBE3000 chips. The programs likely provide an API, (socket interface?) where other programs can send AMBE Frame data and get 8KHz voice data back, and vice versa.

73 Eric

 

[N8OHU]

Interesting; just found out that apparently the DV4home supports full duplex audio. Not sure which mode, though.

Sent from my XT1060 using Tapatalk

 

[iball]

Interesting; just found out that apparently the DV4home supports full duplex audio. Not sure which mode, though.

Sent from my XT1060 using Tapatalk

It doesn't.
It does have two AMBE3000R chips on separate COM1 and COM2 UART ports, but when you key up the audio stops like any other "radio".

In the latest update they hardcoded the DMR IP address in it for the DMR+ server in Naples, FL and some uni over in Germany.
Took all of about 5 minutes to hex-edit it to use Brandmeister. The ONLY reason I can think of for them to do that was a vain attempt to stop me using their hardware on Brandmeister since no one else really knows how to get inside the OS running their hardware.

I've got a Beaglebone Black I'm probably going to use to replace the anemic WEB-IF board the daughtercard with the AMBE and audio codec chips are on. I've already started blueprinting the WEB-IF to daughtercard connections so I can rewire it to the Beaglebone Black running a much more up-to-date version of Debian, on a faster processor (1Ghz vs. 400mhz) with more RAM (512MB vs. 128MB).
Plus I can get rid of that 12v wall-wart/battery power requirement and replace it with 5v USB to power it anywhere. And slap some wireless on it.
Roll a lightly modded OpenDV, ircDDBgateway, and MMDVMHost onto it.
Probably the hardest thing will be writing up a program to make use of the rotary encoder for volume and menu use.

 

[N8OHU]

It's a capability in the newest "firmware" apparently.

Sent from my XT1060 using Tapatalk

 

[iball]

There is no firmware, it's just a tiny tarball of some Linux programs and web pages.
It's a WEB-IF Linux micro-PC plugged onto a custom circuit board.

It all runs off a 4GB micro-SD card. If that card ever goes bad or the Linux OS gets corrupted, you've got a brick you can't fix because they don't provide a recovery image.

I made my own backup of the OS by pulling the card and using Win32diskimager to read it into an IMG file. I then applied the image to a bigger, faster 8GB micro-SD and then used Gparted to expand the main filesystem partition and it runs off that now, while the original micro-SD is safely stored away.

The DMR software they use is also very crashy. Every QSO it spawns a new local UDP socket connection in order to talk to the hardware.
UDP sockets that are never closed and always open. Each socket generates a temp file. Once the number of open files hits 1024, the program crashes. After a minute or two, the OLED program "sees" it's crashed and restarts it. Unfortunately, this has the effect of either not connecting you back to the reflector you were on or connects you to a entirely different reflector.
It was worse in the older software as the OLED program didn't even look to see if the DMR program crashed forcing people to power-cycle the box. I fixed that myself by making the dmr program start through a simple python script that restarts it immediately after it crashes, much faster than the fix they put in the OLED program in this latest version.

The newer software didn't "fix" anything other than restarting the program after a minute or two of it crashing out and hardcoding their server IPs into the DMR program, which was easy enough to change via a hex editor.

So while they've banned me from their official support Facebook group, complained that I'm "harassing" them and to only talk to their lawyers (I've tried, their lawyers never got back to me) they're obviously reading what I'm posting on the nets about the problems I'm finding and trying ham-fistedly to prevent anyone from using their hardware with Brandmeister because they think the BM group "stole" software from them when that one guy released modified DV4mini software that first allowed it to be used with the BM network.

Some of the folks building the DV4home itself used to work on the OpenDV source as well as the old DVRPTER-NET hardware and a lot of that same code can be found in a modified fashion inside the DV4home. They're also the same people behind the DMR+ network so they're pushing hard for DMR+-only use for the box on the DMR side.

Same people doing the DV4mobile too, which should terrify those that plunked down $35 to "reserve" a spot to buy one.

 

[N8OHU]

Well, that's kind of why I put firmware in quotation marks.

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