OFF topic... (or not)

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: OFF topic... (or not)

Post by VK3KYY » Sat Apr 24, 2021 9:16 am

Yes. I know someone in the FreeDMR team

Its definitely something they would consider.

SP2ONG
Posts: 45
Joined: Sat Nov 16, 2019 9:47 am

Re: OFF topic... (or not)

Post by SP2ONG » Sat Apr 24, 2021 10:30 am

The OpenRTX team works on the MD-380 , MD-UV380 modifications

Currently, there is a version of MMDVM / MMDVMHost that supports the M17 protocol
https://github.com/g4klx/MMDVMHost/tree/M17_AX25_FM
There are transition tools from DMR2M17 available
https://github.com/nostar/MMDVM_CM
and we are currently using these solutions but this causes not really using M17 to RF and this is rather the goal so we need HT radios etc. to use M17 natively.

In a similar way, it may not be used by radio NXDN, P25, etc., because the same tools available for switching the DMR network to NXDN and P25, but it is good but it would be good to use such modes on RF :-)

73 Waldek

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: OFF topic... (or not)

Post by VK3KYY » Sat Apr 24, 2021 10:36 am

SP2ONG wrote:
Sat Apr 24, 2021 10:30 am
The OpenRTX team works on the MD-380 , MD-UV380 modifications

Currently, there is a version of MMDVM / MMDVMHost that supports the M17 protocol
https://github.com/g4klx/MMDVMHost/tree/M17_AX25_FM
There are transition tools from DMR2M17 available
https://github.com/nostar/MMDVM_CM
and we are currently using these solutions but this causes not really using M17 to RF and this is rather the goal so we need HT radios etc. to use M17 natively.

In a similar way, it may not be used by radio NXDN, P25, etc., because the same tools available for switching the DMR network to NXDN and P25, but it is good but it would be good to use such modes on RF :-)

73 Waldek
OK.

I was told the MD380 needed hardware modification

They must have found a solution to modifying the hardware

If OpenRTX got that working on the MD380 they will know how to do it on the other radios

No need for anyone else to take time to do this. Its just duplication of effort.


Why dont they support the modes like YSF and P25 etc which also use AMBE ?

AM would also be fun. I'd like that... Retro modes ;-)

Actually AM Tx is already possible. But I don't think AM reception is possible. But perhaps it may be possible to receive AM

SP2ONG
Posts: 45
Joined: Sat Nov 16, 2019 9:47 am

Re: OFF topic... (or not)

Post by SP2ONG » Sat Apr 24, 2021 12:24 pm

Yes, but maybe it would be possible to find a solution without harwdare modification, because with the modification it will still be a barrier for many people. Solution without modification + appropriate firmware there is a chance that the M17 will have a chance to find its place among DV hamradio communication because otherwise it will end up only in a small group but maybe I'm wrong .

oh1fss
Posts: 74
Joined: Mon May 04, 2020 11:53 am

Re: OFF topic... (or not)

Post by oh1fss » Sat Apr 24, 2021 3:26 pm

VK3KYY wrote:
Fri Apr 23, 2021 10:48 pm
The other thing I don't know, is the compile size of codec2. There is not much space remaining in the MCU ROM.
What about the 2 Mb version of DM-1801?

SP2ONG
Posts: 45
Joined: Sat Nov 16, 2019 9:47 am

Re: OFF topic... (or not)

Post by SP2ONG » Sat Apr 24, 2021 3:46 pm

Roger,

If there is not enough space for CODEC2 in OpenGD77, then it can do LITE OpenGD77 versions where, for example, there will be only one ENGLISH language, or would it be possible to recover the memory on CODEC2? or give up some of them to have the OpenGD77 DMR AMBE / Codec2 firmware.
Everyone can run their local FreeDMR server and it's a difficult task see the description available:
https://github.com/hacknix/FreeDMR/wiki

FreeDMR we can run on RPI v4 or VPS computer

On such a server you can try DMR Codec2 and give it access to others. You can also connect this server later via OpenBridge protocol to another FreeDMR server.
I am not an expert on the DMR protocol, but if only the voice data will be instead of AMBE in CODEC2, then by appointing on FreeDRM servers that Talk Group 88 is an International group for calls on DMR Codec2 and Talk Group 888 is a local group for calls on DMR Cocdec2, you can use the current one FreeDMR servers are DMR Codec2 connectivity.

What's more interesting, when using DMR Codec2, the transition to the M17 network will be the same as from DMR to NXDN or YSF narrow, i.e. you will not need to transcode voice, only transcode METData

It would be an interesting experience if we could have OpenGD77 DMR Ambe / Codec2.

73 Waldek

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: OFF topic... (or not)

Post by VK3KYY » Sat Apr 24, 2021 11:17 pm

oh1fss wrote:
Sat Apr 24, 2021 3:26 pm
VK3KYY wrote:
Fri Apr 23, 2021 10:48 pm
The other thing I don't know, is the compile size of codec2. There is not much space remaining in the MCU ROM.
What about the 2 Mb version of DM-1801?
Thats external flash memory, not CPU program memory

All these radios have 512k MCU ROM

Lower 16k is the bootloader
Top 4k is some encryption keys, and if you remove it the bootloaer won't let the radio boot
Official binary sections included for ambe are 172k and 15k = 187k

So space for the firmware is only 305k

Unfortunately because the MCU rom memory map has to be fragmented, by the official firmware blocks, the compiler does not correctly report the remaining space

If you look at the build output you will see this

Code: Select all

   PROGRAM_FLASH:        476 KB       494 KB     96.36%
i.e According to the compiler there is only 20k free.

However I don't think it is accurately reporting the free program space memory, as this value does not decrease very much when new code is added.

I think possibly there is 50 - 100k available, but I don't have a way to determine the amount of program memory which is available.

Post Reply