No RX/TX on MMDVM Simplex modem with RPI4?

MMDVM_HS Hat hardware
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DO8SEB
Posts: 6
Joined: Fri Jul 17, 2020 12:25 pm

No RX/TX on MMDVM Simplex modem with RPI4?

Post by DO8SEB »

hello, may i get your help?

i have bought a RPI4 2gb and just added an MMDVM simplex modem.
Problem: i can't hear anybody talking and the hotspot don't recognices my tx from my radio?
but i can see my hotspot logged in to YSF on ysf-www-dashboard and the gatewayactivity on the pistar-dashboard works.
if someone PTT's in the booked DG-ID on my modem the RED PTT LED comes up. also the blue YSF LED comesup.
if the OM let his PTT go, the blue YSF LED is on for the 30seconds then disappears, but the red PTT LED still is on.
SVC LED is always blinking fast.

settings:
i flashed the newest pistar 4.1.5 to the sdcard an let it run.
Just hooked YSF mode.
display none.
entered Callsign/dmrid/433.625.000Mhz simplex/nodetype private/no aprs enabled.
my modemtype choice in conf.: MMDVM_HS_HAT (DB9MAT & DF2ET) for Pi (GPIO)

in adminpanel all lights green.
HS_HATv1.5.2 so it comes out of the box.

in SSH findmodem says:
Detected MMDVM_HS (GPIO): /dev/ttyAMA0 (MMDVM_HS_Hat-v1.5.2 20201108 14.7456MHz ADF70
21 FW by CA6JAU GitID #89daa20ABCD2CF01C37437A2000410F)

if i boot up the pi, the powerled on the mmdvm modem lights up green, if pistar is booted, the svc light blinks in red 5 times slow, then always fast.
i tested mmvdmcal but doesnt recognize any rx.
offset sticker on the modem says -475, which i set in. but i also tested from -500 to +500 in 50steps.

Image
link to img: https://ibb.co/Sr5PhM7

do you know where my problem is?

i'd like to say big thanks to the help from you guys in this forum! you are doing a nice job and very friendly!

best regards
sebastian DO8SEB
73, Sebastian

Dipl.-Ing.(FH), DO8SEB @ Pi-Star MMDVM with Anytone D578/878.
KE7FNS
Pi-Star Team
Posts: 2077
Joined: Wed Apr 17, 2019 11:11 pm

Re: No RX/TX on MMDVM Simplex modem with RPI4?

Post by KE7FNS »

DO8SEB wrote: Sat Sep 11, 2021 10:10 am do you know where my problem is?
What radio are you using? And are you sure it is programmed correctly for simplex operation and not transmitting on a repeater offset.

Other than that YSF seems to be very picky with which radios and modes it works with. If I remember correctly, it only works in DN mode and not VW although the testing some of the dev's did they didn't have any issues with either mode so it seems to be radio specific. It doesn't help when Yaesu themselves comes out and says they only support their own repeater products and not 3rd part devices (hotspots).

Everything else you've posted seems to indicate the device is functioning just fine, so it has to be a RF issue where the hat isn't properly seeing or recognizing the signal.
If someones previous actions are any indication of their future actions, then I predict the deletion and removal of access will happen at any moment. 7-11-2020.

"07/13/20 This Website Has Been Taken Down" ... again :lol: and again
DO8SEB
Posts: 6
Joined: Fri Jul 17, 2020 12:25 pm

Re: No RX/TX on MMDVM Simplex modem with RPI4?

Post by DO8SEB »

Thanks for thoughts!

I use an ftm400 or ft3d. Both are working on my other zero pi with an Mmdvm fine!
I also can change to dmr. Therefore i use an Anytone which is programmed Right. Same issue.

I think the Modem is numb. Next step for me, i will put a spectrum analyser on the antenna directly connected with koax and Test the spectrum.

I wanted to setup this new hotspot with an nextion display in a new case. My other hotspot just has a modem hat without display. But first the modem has to work properly before I add the nextion with programming on it. Step by step you know.

I will tell you the result of the spectrum analysis these days:).

can you tell me looking at the image above which modem type this is?
because if i am trying to flash the firmware, i always use mmdvmhshat software, thats right?
i also get the problem, at the first boot up, there is no modem in "findmodem" command, and the svc led doesnt appear. then i reboot, and just at the second boot i got the svc led and in findmodem there is the modem...

edit:
i startet pistar-mmdvmcal and used the deviationmode (D)
therefor the dmr led lights up... good.
and the ptt led lights up if i press space...good.

at the spectrumanalyser no signal!

then i press space again to stop ptt, nothing happens! the pi hangs in. i have to quit and reboot...
73, Sebastian

Dipl.-Ing.(FH), DO8SEB @ Pi-Star MMDVM with Anytone D578/878.
KE7FNS
Pi-Star Team
Posts: 2077
Joined: Wed Apr 17, 2019 11:11 pm

Re: No RX/TX on MMDVM Simplex modem with RPI4?

Post by KE7FNS »

DO8SEB wrote: Sun Sep 12, 2021 7:57 am can you tell me looking at the image above which modem type this is?
because if i am trying to flash the firmware, i always use mmdvmhshat software, thats right?
I've never seen that board design before, so its definitely a new clone, I wasn't able to find an image that matched it so I have no idea what it is. The MMDVM silkscreen in the lower left and the LEDS all in a row are key differences to known designs, perhaps it has incorrect traces or substandard parts installed.

Since you say things work in another hotspot, it definitely points to the hat. I would buy a quality board and avoid the cheap clones. You get what you pay for.
DO8SEB wrote: Sun Sep 12, 2021 7:57 am i also get the problem, at the first boot up, there is no modem in "findmodem" command, and the svc led doesnt appear. then i reboot, and just at the second boot i got the svc led and in findmodem there is the modem...
That is an issue when using the RPi 4 models. They boot with their GPIO signals in a different configuration than all the other RPi's it has the conflict that the MMDVM_HS hat can get stuck in bootloader mode and not run its code properly.

The only fix is to either not run a RPi 4 (honestly a RPi 4 is a waste to use only on a hotspot, plus they run much hotter than RPi 3's), or make sure you select "MMDVM_HS_Hat (DB9MAT & DF2ET) for Pi(GPIO) so the built in processes can issue a reset to the modem during the boot.

DO8SEB wrote: Sun Sep 12, 2021 7:57 am edit:
i startet pistar-mmdvmcal and used the deviationmode (D)
therefor the dmr led lights up... good.
and the ptt led lights up if i press space...good.

at the spectrumanalyser no signal!

then i press space again to stop ptt, nothing happens! the pi hangs in. i have to quit and reboot...
If the RPI hangs how do you quit and reboot it? I think you meant to say the MMDVMCal software hangs, but not the RPi.

Could be a serial port issue, or a problem with the MMDVM_HS hat.
If someones previous actions are any indication of their future actions, then I predict the deletion and removal of access will happen at any moment. 7-11-2020.

"07/13/20 This Website Has Been Taken Down" ... again :lol: and again
DO8SEB
Posts: 6
Joined: Fri Jul 17, 2020 12:25 pm

Re: No RX/TX on MMDVM Simplex modem with RPI4?

Post by DO8SEB »

Thanks a lot for your Time! I‘m happy to know the bootproblem is an rpi4 Problem.

I have checked the capacitors on the Board. There are 10nf has to be 1nf, there are 1nf where has to be pico.

No chance, I bought a real board from db9mat. I think this will work!comes tomorrow.

The rpi4 was lying around, so I took the sucker. It is running on 60-65degrees without any cooler.
With passive 60, with minishim 55. I think it has to work until he dies, then I buy a rpi3:).

And yes, for sure the Mmdvm cal hangs, Not the pi. I am an Engineer having some skills in programming, this comes out of usually programming CAE/CNC machines.

So very big thanks for your knowledge and tips in this!!!!
The forum is nothing without you.

If I can help you in some machinery specialties, please contact me.
73, Sebastian

Dipl.-Ing.(FH), DO8SEB @ Pi-Star MMDVM with Anytone D578/878.
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