Curious about a failure

MMDVM_HS Hat hardware
kd4iz
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Curious about a failure

Post by kd4iz » Thu Jun 11, 2020 4:01 pm

Of several hotspots, I have one mmdvm_hs hat - acquired second hand. Worked fine for quite a while (year or so). Pwr was always from a UPS and the unit was usually on unless exercising lightning precautions and I shut the entire station down.

Fail occurred last week - it went deaf and dumb and the OLED display went blank. The Pi-Star dashboard stopped showing any info in the Radio Info Trx block. Did not have a schematic or measurement parms list... but attempted several things:
1. Pi-Star Update - performed as expected but nada
2. Pi-Star Upgrade - performed as expected but nada
3. Firmware Update - performed as expected but nada - messages in the SSH window did not suggest a problem to me.
4. Started with a new image on new SD - never could get it to settle down during configuration - kept forgetting modem type and losing the WiFi configuration...
5. Just for S&G, swapped in another known Pi Zero WH board and used working SD card - same results...
6. Put the original configured SD back in and it continues to "look like" everything "else" is OK.

*Have not taken the logic probe to it* -too much trouble and it is not my primary hotspot, so really would do this out of curiosity.
Even though sequestering and pretty bored, I gave up playing at that point and ordered another US$60 hat from our friends at Amazon.
So if any hardware tech wizard(s) would like to help educate me a little here - where is the most likely point(s) of failure to probe on the hat? It might be an interesting exploration.

Thanks in Advance - KD4IZ

KE7FNS
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Re: Curious about a failure

Post by KE7FNS » Thu Jun 11, 2020 7:31 pm

kd4iz wrote:
Thu Jun 11, 2020 4:01 pm
3. Firmware Update - performed as expected but nada - messages in the SSH window did not suggest a problem to me.
If there were no errors when you flashed the hat, that eliminates the serial port and the STM32 (on the hat) from list of what could of failed.

Since you said the flash went without failures, and the OLED is blank, that means that there is no communication from the RPi to the hat and since the flash worked correctly but normal operation doesn't that leads me to believe you have a simple configuration issue in software.
kd4iz wrote:
Thu Jun 11, 2020 4:01 pm
4. Started with a new image on new SD - never could get it to settle down during configuration - kept forgetting modem type and losing the WiFi configuration...
That wouldn't be anything to do with the Hat, that would be isolated to the physical RPi or the SD card. Some brands and models of SD cards have compatibility issues reported by users.

kd4iz wrote:
Thu Jun 11, 2020 4:01 pm
6. Put the original configured SD back in and it continues to "look like" everything "else" is OK.
You are probably experiencing a dashboard bug where it accidentally set an incorrect port configuration for the hat. It was fixed, so make sure you are on the latest version of the dashboard 20200528, and then go in and double check your display type and port location setting.

If that bug is the cause checking the logs would of reported the "Unable to read the firmware version after six attempts" error.

Can read all about it here:
viewtopic.php?f=3&t=2753


Also, could be SD card compatibility, I've ran into a few CD cards that like to corrupt themselves randomly.
https://elinux.org/RPi_SD_cards
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:

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G8SEZ
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Re: Curious about a failure

Post by G8SEZ » Thu Jun 11, 2020 8:47 pm

If the TCXO for the ADF7021 clock input fails then the symptoms you describe are possible, you can flash the board because the STM32 clock is running but the STM32 cannot talk to the RF chip.

Sometimes cheap TCXOs fail, sometimes they have defective soldering because the PCB footprint is not right for the package pads.

I repaired one of my Hats that never initialised properly, it was cheaper than trying to get a refund on eBay.
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Brian G8SEZ

KE7FNS
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Re: Curious about a failure

Post by KE7FNS » Thu Jun 11, 2020 9:30 pm

G8SEZ wrote:
Thu Jun 11, 2020 8:47 pm
If the TCXO for the ADF7021 clock input fails then the symptoms you describe are possible, you can flash the board because the STM32 clock is running but the STM32 cannot talk to the RF chip.
If that were the case the "running" STM32 would still be communicating with the OLED and it wouldn't be blank.
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:

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G8SEZ
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Re: Curious about a failure

Post by G8SEZ » Fri Jun 12, 2020 1:54 pm

KE7FNS wrote:
Thu Jun 11, 2020 9:30 pm
G8SEZ wrote:
Thu Jun 11, 2020 8:47 pm
If the TCXO for the ADF7021 clock input fails then the symptoms you describe are possible, you can flash the board because the STM32 clock is running but the STM32 cannot talk to the RF chip.
If that were the case the "running" STM32 would still be communicating with the OLED and it wouldn't be blank.
Maybe, but if you also have the logo screensaver set to 0 due to fairly recent changes then I think it's possible. I was convinced by the lack of Rx and Tx too.
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KE7FNS
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Re: Curious about a failure

Post by KE7FNS » Fri Jun 12, 2020 7:12 pm

G8SEZ wrote:
Fri Jun 12, 2020 1:54 pm
Maybe, but if you also have the logo screensaver set to 0 due to fairly recent changes then I think it's possible. I was convinced by the lack of Rx and Tx too.
The LogoScreensaver configuration setting only affects the "mode" logo in the statusbar, it does not hide the rest of the information displayed on the screen.

https://github.com/g4klx/MMDVMHost/blob ... D.cpp#L619
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:

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G8SEZ
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Re: Curious about a failure

Post by G8SEZ » Fri Jun 12, 2020 8:01 pm

KE7FNS wrote:
Fri Jun 12, 2020 7:12 pm
G8SEZ wrote:
Fri Jun 12, 2020 1:54 pm
Maybe, but if you also have the logo screensaver set to 0 due to fairly recent changes then I think it's possible. I was convinced by the lack of Rx and Tx too.
The LogoScreensaver configuration setting only affects the "mode" logo in the statusbar, it does not hide the rest of the information displayed on the screen.

https://github.com/g4klx/MMDVMHost/blob ... D.cpp#L619
No, but if it can't transmit or receive then it's unlikely that there is anything to display. I had exactly this myself, replacing the TCXO fixed it. I did have messages in the log indicating problems, but they were not of the "can't do anything, can't find firmware ID string" type. Thinking very hard (this was in 2018), I recall messages containing "RF queue" or something similar. This happened after the Phoenix IPSC2 server connection was made and the PiStar was trying to transmit the "connected to reflector" audio message.
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KE7FNS
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Re: Curious about a failure

Post by KE7FNS » Fri Jun 12, 2020 8:38 pm

G8SEZ wrote:
Fri Jun 12, 2020 8:01 pm
No, but if it can't transmit or receive then it's unlikely that there is anything to display.
The OLED would of still displayed information after booting and when it entered the first idle mode since that has no direct relation to TX or RX. I also believe it would still be displaying information every idle mode even without a proper TCXO.
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:

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G8SEZ
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Re: Curious about a failure

Post by G8SEZ » Sat Jun 13, 2020 1:10 pm

KE7FNS wrote:
Fri Jun 12, 2020 8:38 pm
G8SEZ wrote:
Fri Jun 12, 2020 8:01 pm
No, but if it can't transmit or receive then it's unlikely that there is anything to display.
The OLED would of still displayed information after booting and when it entered the first idle mode since that has no direct relation to TX or RX. I also believe it would still be displaying information every idle mode even without a proper TCXO.
Interesting, this isn't what my Pi0W plus Jumbospot PiStars do, in particular I have one that is on the Brandmeister UK server, reflector 4400 which never shows anything in the Trx field on the dashboard until it has seen activity from at least one local or network station. Pretty sure it doesn't show anything on the OLED either, but maybe that appears when something has communicated with the radio successfully.

When I get a clear hour I am going to have a look at this in more detail and check my settings carefully.
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KE7FNS
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Re: Curious about a failure

Post by KE7FNS » Sat Jun 13, 2020 7:02 pm

G8SEZ wrote:
Sat Jun 13, 2020 1:10 pm
Interesting, this isn't what my Pi0W plus Jumbospot PiStars do, in particular I have one that is on the Brandmeister UK server, reflector 4400 which never shows anything in the Trx field on the dashboard until it has seen activity from at least one local or network station. Pretty sure it doesn't show anything on the OLED either, but maybe that appears when something has communicated with the radio successfully.

When I get a clear hour I am going to have a look at this in more detail and check my settings carefully.
An OLED will display "Startup" right after booting and before it enters the first idle page and then on the idle page it may or may not display the logo depending on the logoscreensaver configuration you mentioned, and if the network has been initialized it will display the IP address.
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:

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