P25RX Firmware Updates / Testing

[krokus]

Hi Todd,

I know it has been a long time since I last reported in - been busy both in terms of work and personal life; even so, I have tried to follow your new versions and keep updated.

I regret to say that my long standing issue of "talk group bleedthru" is still occuring in the system I monitor and, until recently, it was extremely frustrating for me because I could not find some kind of pattern associated with it's occurance that may assist you in solving the issue, BUT I MAY finally have an observation that may help you investigate this issue!

I usually only keep the "Talk Group Log" screen up as I find the Console too "busy" and distracting for me while I am working. Unfortunately, the Talk Group Log screen does not show whether the received signal is P1 or P2 and, as you may recall, the system I listen to is a P25 P1 and P2 system with most Talk Groups being P1 but with a growing number of P2 talk groups in the mix.

What I have started to notice most recently is that, if I am looking at the Console screen when I get the "bleedthru" issue is that it seems like it is happening to P2 talk groups with P1 audio from other talk groups leaking thru. I think I would have seen this earlier if I could have seen that the TG was being received as P1 or P2 in the Talk Group Log screen.

When I now watch the Console screen and see and hear this issue happening it now looks like while the P2 TG is active and a conversation is taking place, in between gaps in the conversation I will hear audio from a completely different P1 TG. I am now seeing that, at least sometimes when this occurs, I see the Console data suddenly shift to showing P1 and then switch rapidly back to P2 when the original "correct" conversation continues. Sometimes, the P1 interfering traffic may last long enough to cause the desired P2 TG reception to miss occasional replies but often the P1 interfering traffic will abruptly cease when a reply comes back on the desired P2 TG.

I am not sure but it looks like the P2 traffic is subject to "interference" from the P1 traffic (which, on this system, still comprises the majority of the traffic) and may be more pronounced during busy periods (which would make sense). Maybe when the P1 "interference" causes the missing of replies during a P2 TG conversation it might be because the reply was on another time slot in the P2 transmission? That is just conjecture as I can't tell which slot the P2 traffic is carried on, of course.

Assuming that the above observation is correct (P1 traffic bleeding thru into P2 traffic), then I am guessing that if one is monitoring a pure P2 system with no mixing of P1 TG's or a pure P1 system with no mixing of P2 TG's this issue would never show itself.

Stupid question: Have you checked if you are hearing audio from the other time slot on the P2 signal as the interference?

 

[Napalm]

Weird observation - I have my P25RX in the car with me for my hour commute. I leave it in the car for my shift and when I get back to it, it won't load up. I get the power light, and then it looks like its power cycling (the sig/tg light flash together and the sig light is a blue-green mix).

The unit has been getting really cold (sub 0C/32F) when I have left it in my car. When I throw it up on the vent for the front window and warm it up it starts to work fine LOL.

This is not a complaint I am just trying to figure out if it doesnt like being left in the cold for 8 hours.

 

[btt]

Stupid question: Have you checked if you are hearing audio from the other time slot on the P2 signal as the interference?

I don't think the slot decode has issues. Every burst is checked to make sure it is the right slot and the handler is aborted if it is not. The issue that Mike has found is most likely related somehow to the "roaming/scanning" mode of operation.

Weird observation - I have my P25RX in the car with me for my hour commute. I leave it in the car for my shift and when I get back to it, it won't load up. I get the power light, and then it looks like its power cycling (the sig/tg light flash together and the sig light is a blue-green mix).

The unit has been getting really cold (sub 0C/32F) when I have left it in my car. When I throw it up on the vent for the front window and warm it up it starts to work fine LOL.

This is not a complaint I am just trying to figure out if it doesnt like being left in the cold for 8 hours.

I don't currently have access to a controlled temperature chamber for testing since I quit my last place of employment. I did however put the prototypes in the freezer and oven for testing. No issues with those. I don't believe I characterized temperature performance in the user manual, but the design should be ok down to -30C based on part specifications and the testing of similar previous designs. Do you have the new option in the advanced tab for "P25 Mode: Re-init after 3 minutes of no sync" enabled by chance? That might explain the reset. If that is the case, I may need to allow the frequency correction to correct out further to allow compensation for temperature extremes. I know that the HW is capable of correct operation from -30 to +70C. (or better). There definitely have been changes to the frequency correction code since the initial testing of the prototypes. I will look into this. Thanks.

 

[Mike_G_D]

Stupid question: Have you checked if you are hearing audio from the other time slot on the P2 signal as the interference?

As stated - the interfering audio is coming from known P1 talk groups so would, I believe, not be from the opposite P2 time slot (unless they are simultaneously putting the P1 traffic on some P2 time slots, which maybe could be as the system is slowly transitioning from mixed P1 and P2 TG's to all P2). Also, I know of no way to select or toggle between time slots on P2 TDMA traffic while holding on an active known P2 TG with the P25RX.

-Mike

 

[Mike_G_D]

Also want to reiterate that I have tried disabling roaming before and still saw the issue I described. But I am not sure how long ago that was (think not very long ago) so am unsure how changes since then may have changed things since. I'll try the new version that Todd mentioned to me and try disabling roaming again now that I know to check the P2/P1 type in the Console when the problem occurs.

-Mike

 

[Cheeseburgers]

Setup a t410 as a dedicated P25rx rig, in a giant pelican case paired with a Shure 700/800 and its going strong. Awesome device!

 

[krokus]

Weird observation - I have my P25RX in the car with me for my hour commute. I leave it in the car for my shift and when I get back to it, it won't load up. I get the power light, and then it looks like its power cycling (the sig/tg light flash together and the sig light is a blue-green mix).

The unit has been getting really cold (sub 0C/32F) when I have left it in my car. When I throw it up on the vent for the front window and warm it up it starts to work fine LOL.

This is not a complaint I am just trying to figure out if it doesnt like being left in the cold for 8 hours.

Are you using the internal battery, or external power?

 

[btt]

Are you using the internal battery, or external power?

Good thought, but there is no internal battery on the P25RX.

I measured the temperature in my freezer to be -17C. I have a receiver cooling now. I'll post what happens this eve. If there is an issue, I'll get it fixed.

 

[relicwr]

Setup a t410 as a dedicated P25rx rig, in a giant pelican case paired with a Shure 700/800 and its going strong. Awesome device!

I miss the ThinkPads like they were. Good choice though. I have yet to find a 2-in-1 or decent tablet to run that plus other things from other dongles for my car.

 

[Cheeseburgers]

yeah the durability of the thinkpads is/ was awesome, best keyboards too

 

[btt]

I measured the temperature in my freezer to be -17C. I have a receiver cooling now. I'll post what happens this eve. If there is an issue, I'll get it fixed.

Just tested the unit after cooling to -17C. Came right up and started receiving with no issues. The TCXO was pretty close (error=15 Hz). The frequency correction was approximately 350 Hz at a receiver frequency of 859 MHz.

 

[btt]

Weird observation - I have my P25RX in the car with me for my hour commute. I leave it in the car for my shift and when I get back to it, it won't load up. I get the power light, and then it looks like its power cycling (the sig/tg light flash together and the sig light is a blue-green mix).

The unit has been getting really cold (sub 0C/32F) when I have left it in my car. When I throw it up on the vent for the front window and warm it up it starts to work fine LOL.

This is not a complaint I am just trying to figure out if it doesnt like being left in the cold for 8 hours.

@Napalm, see the previous post for temp testing results here @ -17C. As you can see, the TCXO does a good job of correcting for temperature. What is your receiver showing for "Estimated Reference Frequency" on the Signal Insights tab while monitoring a P25 CC? What is it showing for "Reference Frequency" on the P25RX Config tab? Also, can you check the advanced tab and see if you have the P25 Mode: Re-init option enabled or disabled?

 

[btt]

yeah the durability of the thinkpads is/ was awesome, best keyboards too

This is the keyboard I have worked on for many years now. I bought big boxes full of them back when I made the big bucks.

 

[vince48]

Hi Todd,
Do you have any time table when the P25RX will be able to trunk and not just scan all DMR modes?

 

[btt]

Hi Todd,
Do you have any time table when the P25RX will be able to trunk and not just scan all DMR modes?

Currently DMR only does con+ trunked or conventional (not scanned). I think you meant NXDN. I know I said I would try to work on the NXDN trunking by the first of the year, but I was only able to get NXDN scanning going. I apologize. If I take the time to work on NXDN trunking right now, it will take a very long time to get back to all the features that everyone else wants. I seem to be getting further behind. This isn't a bad thing. It means that the P25RX feature set is wanting to grow faster than one person can keep up with. It may be time for me to start considering making the P25RX open-source. There would be possible up-sides and certain down-sides if I do this. Let me contemplate ways that I might be able to speed up the development process. Raising the cost of hardware and outsourcing the majority of manufacturing might be another solution..

 

[dcr_inc]

Todd,
WORK AT YOUR SPEED... We can all wait for the EXTRAS.. They weren't offered when we bought the unit so NONE of us should be forcing their development.
Take a break, you certainly deserve it!!

 

[btt]

Todd,
WORK AT YOUR SPEED... We can all wait for the EXTRAS.. They weren't offered when we bought the unit so NONE of us should be forcing their development.
Take a break, you certainly deserve it!!

Thank you. I appreciate the feedback. What Vince is asking about is not unreasonable.. Last year, I said I would shoot for working on NXDN trunking by the first of the year. That has come and gone. lol. I don't feel that anyone has forced any development. I do take breaks, but sometimes I'm really soldering and/or taking care of other things beside firmware.

Are there any interested embedded 'C' developers here? Another option to speed things up might be to crowd-source another firmware / software developer?

 

[krokus]

Are you using the internal battery, or external power?

Good thought, but there is no internal battery on the P25RX.

Oh... I thought I saw someone post about using the internal battery. Ok, that is good to know.

 

[daviddehaney]

Does anyone have BTConfig working on a Pine Phone? It loads but the sizing is wrong (too big for Pine Phone screen)

 

[btt]

Does anyone have BTConfig working on a Pine Phone? It loads but the sizing is wrong (too big for Pine Phone screen)

Cool! How far off is the size?