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[Solved] Cannot update MMDVM_HS HAT on a JSTVRO Duplex Hotspot

Posted: Wed Jan 27, 2021 2:26 pm
by dl9sec
Hi,

I recently bought this guy at "Jeff's General Store":

Image
Image

It's a JSTVRO MMDVM Duplex Hotspot. Really nice and tiny.

It has a Raspberry Pi Zero W with a "STM32-DVM / MMDVM_HS – Raspberry Pi Hat (GPIO)" MMDVM_HS_Dual_Hat piggybacked.
All setup went fine so far. The MMDVM_HS firmware 1.4.17 was delivered on the modem.

After a 'rpi-rw' and update/upgrade of the Pi-Star stuff, I tried to update the modem firmware via Pi-Star with

Code: Select all

sudo pistar-mmdvmhshatflash hs_dual_hat
which ends up in a

Code: Select all

:
Using Parser : Raw BINARY                                                            
Interface serial_posix: 57600 8E1                                                    
Failed to init device.
:
It took me several days to investigate the reason for that.
Finally I found out, that there is obviously a design incompatibility at the MMDVM_HS Hat:
The connection between pin 40 of the RPi Zero W connector to pin 7 of the STM32 (NRST) is missing. With appropriate tools (microscope, fine soldering iron, ...) the missing connection can be wired.
Then a connection between pin 4 (to STM32 BOOT1/PB2 via 10k) and pin 6 (GND) of the unpopulated 6-pin header footprint must be made. As far as I see, this connection can stay like in other MMDVM_HS designs after programming.

With these modifications it was possible to update the MMDVM_HS_Dual_Hat from 1.4.17 to 1.5.2.

Hope this helps...

73, Thorsten

Re: [Solved] Cannot update MMDVM_HS HAT on a JSTVRO Duplex Hotspot

Posted: Wed Jan 27, 2021 7:01 pm
by KE7FNS
dl9sec wrote: Wed Jan 27, 2021 2:26 pm With these modification it was possible to update the MMDVM_HS_Dual_Hat from 1.4.17 to 1.5.2.
It looks like the 4 ST-Link pads were included in the design, you should of been able to update the firmware with a 2$ ST-Link clone and soldering 4 pins.

Either way the board designer should be contacted so that he can update the design.

Re: [Solved] Cannot update MMDVM_HS HAT on a JSTVRO Duplex Hotspot

Posted: Wed Jan 27, 2021 7:40 pm
by G8SEZ
It looks like this is a modified clone of the design from here:

https://github.com/phl0/MMDVM_HS_Dual_H ... /r2.0-mini

which has SMA RF connectors substituted and the OLED pads added on but for some reason is missing the programming connections to the RPi.

It's almost as if some people don't really know what they're making.

Re: [Solved] Cannot update MMDVM_HS HAT on a JSTVRO Duplex Hotspot

Posted: Thu Jan 28, 2021 12:05 am
by KE7FNS
G8SEZ wrote: Wed Jan 27, 2021 7:40 pm It's almost as if some people don't really know what they're making.
Yeah, and its even worse that some people don't know what they are buying and just going for the cheapest stuff on e-bay or alliexpress.

We need a listing of crappy boards for people to avoid.

Re: [Solved] Cannot update MMDVM_HS HAT on a JSTVRO Duplex Hotspot

Posted: Thu Jan 28, 2021 5:55 am
by dl9sec
The device doesn't look crappy, wasn't that cheap and bought at Amazon.
To be honest, I couldn't find a list of the good and the bad guys.

Just want to let others know, how this modem can be flashed with the Pi-Star tools, without an extra toolchain...

73, Thorsten

Re: [Solved] Cannot update MMDVM_HS HAT on a JSTVRO Duplex Hotspot

Posted: Thu Jan 28, 2021 5:59 am
by dl9sec
KE7FNS wrote: Wed Jan 27, 2021 7:01 pm Either way the board designer should be contacted so that he can update the design.
They will get feedback via Amazon...

Re: [Solved] Cannot update MMDVM_HS HAT on a JSTVRO Duplex Hotspot

Posted: Thu Jan 28, 2021 9:15 pm
by KE7FNS
dl9sec wrote: Thu Jan 28, 2021 5:55 am Just want to let others know, how this modem can be flashed with the Pi-Star tools, without an extra toolchain...
Thats the problem though, most of the users posting on this forum don't have the capability/ability to manually run new bodge wires. It should just work correctly without any modifications needed.
dl9sec wrote: Thu Jan 28, 2021 5:59 am They will get feedback via Amazon...
The seller probably has no association to the board designer. The seller probably just snagged a PCB layout from somewhere on the net and had a bunch of boards spun up and populated and is trying to make a few bucks here and there.