MMDVM board not receiving DStar

Help with D-Star related issues
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pe2kmv
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MMDVM board not receiving DStar

Post by pe2kmv »

Hi all,

I've already searched the forum but couldn't find anything like my issue... First my gear:

- Raspi Zero W
- Pi-Star 4.1.6
- MMDVM HS-HAT (original by DF2ET)
- MMDVM HS-HAT (Chinese board)
- Icom IC-92AD

Since a long time I wanted to play with DStar again. Strangely enough de hotspot didn't receive (or decode?) DStar anymore. It transmits and the transmitted signal is perfectly decoded by the radio. But when pushing PTT the hotspot doesn't react to the RF signal.

This is what I've tried so far:
- checked my radio settings: QRG is correct, split is enabled and set to 0 MHz, UR set to CQCQCQ, R1 and R2 set for my hotspot --> all set
- used my radio on a regional DStar repeater --> works like a charm, so the radio is okay
- checked the DStar settings in Pi-Star --> enabled
- checked the MMDVM with DMR --> RX and TX work like a charm
- swapped the original HS-HAT with a Chinese clone --> still the same issue!
- zapped a fresh image of Pi-Star on a card and started all over with both boards --> still the same issue!

Now I'm running out of ideas. Am I the lucky guy who got two boards on the blink...? I'm happy if someone only can think along with me!

73,
Ronald pe2kmv
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G8SEZ
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Re: MMDVM board not receiving DStar

Post by G8SEZ »

What firmware do you have on the HS-HAT? Latest is 1.5.2 in case you have a much older one.
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Brian G8SEZ
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Re: MMDVM board not receiving DStar

Post by AF6VN »

Silly question, but you /have/ linked a reflector through the hotspot?

{Also, use the lowest power level your radio supports -- 50mW is often sufficient; much higher powers could overload the front-end of the RF board unless you are down the block when testing}

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Dennis L Bieber
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Re: MMDVM board not receiving DStar

Post by M1DNS »

Whats being reported in pistar live logs when you key up?

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pe2kmv
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Re: MMDVM board not receiving DStar

Post by pe2kmv »

Hi all,

Thanks for you replies. To complete the story:

- both boards indeed have the 1.5.2 firmware
- the original board by DF2ET has worked fine on DStar, but I haven't used it for a (very) long time with this mode
- power level has been set to 0.01W
- in DMR mode RX and TX are fine (so the RF section of the board seems to be okay)
- POCSAG TX is also happy
- there's not difference whether I've linked a reflector via the dashboard. Traffic via the network is perfectly transmitted, but the bloody thing refuses to listen to DStar...
- and it really puzzles me that 2 boards have exactly the same (mis)behavior...

73,
Ronald pe2kmv
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G8SEZ
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Re: MMDVM board not receiving DStar

Post by G8SEZ »

Do you know someone else with a working DSTAR radio? Perhaps you can get a comparison, although I know you said yours works via a local DSTAR repeater.

It feels like a software configuration issue if 2 separate HS-HATs do it, but not sure where to look.
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Brian G8SEZ
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Re: MMDVM board not receiving DStar

Post by G8SEZ »

OK, I have just had my memory jogged on this.

If you don't have the modern Icom radios set to DUP mode with an offset of 0MHz then the hotspot won't recognise the address fields or the radio doesn't send them correctly. But, as this is an older generation of radio maybe something is different in this respect.

Try changing these settings and see if it helps.

There's a lot of good advice on this from K9WLW on Youtube.
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Re: MMDVM board not receiving DStar

Post by M1DNS »


G8SEZ wrote:
... But, as this is an older generation of radio maybe something is different in this respect.
.
No its always been that way. The way it was reverese engineered was in keeping with the then icom repeater expectations.
(Hotspots weren't a thing in those days)

Some other hardware, software guys relaxed that part of the protocol but KLX offerings make use of duplex enabled to feed from the rpt2 field.
(Simplex mode doesnt carry the rpt2 data)

dstargateway had a ability to enable disable that dependency but AFAICS it never got written back into mmdvmhost.

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Re: MMDVM board not receiving DStar

Post by M1DNS »

It looks like you might already have it setup but maybe check the forum FAQ section headed using dstar mode in pistar as a checklist as it does sound like something is not set correct in the radio.

If you post the pistar live log report when keying up it might show an issue and help us here quicker point you to where any missing setup lies.

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