FM APRS

[OK2MOP]

Concerning the limits of MD-9600, just a two ideas which have been floating in my head:

1. The MIC-E (or other) compression could be implemented to shorten the initial message.
2. I was not able to find answer to this in APRS PROTOCOL REFERENCE PDF nor on web, so somebody with more in-depth knowledge can answer this, but would it be possible to split the message into two separate APRS packets sent separately (of course with full set of address fields) after each other, one containing coordinates and another the comment (and altitude) batched like when telemetry is transmited?

[VK3KYY]

Concerning the limits of MD-9600, just a two ideas which have been floating in my head:

1. The MIC-E (or other) compression could be implemented to shorten the initial message.
2. I was not able to find answer to this in APRS PROTOCOL REFERENCE PDF nor on web, so somebody with more in-depth knowledge can answer this, but would it be possible to split the message into two separate APRS packets sent separately (of course with full set of address fields) after each other, one containing coordinates and another the comment (and altitude) batched like when telemetry is transmited?

In the long term I will need to write the full wavetable pwm GPIO AFSK system, but this is many hours of work

Comment is part of the APRS packet type, AFIK it can't be send separately

Status text can however be sent separately

[VK3KYY]

First of all, I would like to thank you and the whole dev team for this feature add, and plus the other features and bug fixes. Congrats to all!

As for the square wave signal, I am not sure if a simple RC filter circuit in place could smoothen it to approxmiate a sine wave to get a usable signal out of it?

Great work, Roger and everyone else involved!

0.1% of all OpenGD77 users would be willing to take their radio apart and make modifications.

And anyway, I have a solution to the problem on the MD-9600, I just don't have 50+ free hours of time to develop the software fix.

[VK3KYY]

0.1% of all OpenGD77 users would be willing to take their radio apart and make modifications.

And anyway, I have a solution to the problem on the MD-9600, I just don't have 50+ free hours of time to develop the software fix.

Indeed!

I know you guys are very busy working on these developments! Thank you so much again.

I just checked and on the GD77 we have 5k of program memoryt free for any extra functionality. This is somewhat limiting, I'm not sure if APRS decoding will fit into 5k

At this rate, we may have to trade off language(s) support for functionality

[VK3KYY]

I just checked and on the GD77 we have 5k of program memoryt free for any extra functionality. This is somewhat limiting, I'm not sure if APRS decoding will fit into 5k

At this rate, we may have to trade off language(s) support for functionality

Yes, I remember you mentioned that before, it's more critical on the GD77 than on the other models, b/c of the CPU it has.

5KiB is indeed very tight for such a big function.

BTW, I will bring out my RT3s (and or the other ones) outside to do some tests on this APRS function tonight.

The STM32 chips have 2 x the program ROM. HOWEVER... The Donor firmware is also much larger, so there may not be that much extra space available on the STM32 based radios (UV380/MD9600/DM1701)

[VK3KYY]

I did some basic tests of this new function w/ my GD77, RT3s and RD-5R. I have observed that not all the packets were picked up by the iGates, but at least 2 did for the GD77 (w/ a Nagoya 701 antenna, genuine one), and the RT3s (stock antenna) (once only), but none for the RD-5R (on a short stubby antenna which isn't very good, from Retevis bought separately).

The RT3s took 20 mins in outdoor setting (I was walking to and then around a park) to acquire a fix, at least 15 mins to get the first sat signal. I really like the 3 sat screens, and they look just as good as other GPS receiver screens (HW or SW ones) I have used. It's just amazing (My Anytone D878UV doesn't even have such a rich info display.) I will re-read the GPSr antenna upgrade thread and will do the upgrade for my RT3s. It's really worthwhile now to have it done!

Haven't tried this on my MD-9600 yet, as it requires a little more set up, but I am sure if one works, they all should!

Even manually entering the coordinates isn't too bad for occasional users, just not as an automatic tracker, that's all.

I now have an idea about the APRS icon. I will update my radios to use diff icons from now on, so I can easily tell which radio makes it to the iGate etc. Will use "0", "1", "2" and so on, I guess.

Thanks for such a useful feature add. So amazing and I didn't expect this at all, as I thought it was not feasible in these radios. Now it makes my Anytone D878UV a run for the money!

73,

You can also change the SSID

[VK3KYY]

Tested the RD-5R for FM APRS on a second day, I did 2 TXs at different location (but of course the coord was fixed due to no GPSr in RD-5R), and I couldn't find my packets on aprs.fi . I will test it again today, yet with another antenna, to see if it's just poor signal or something else. All 3 radios were on the same beta firmwares (latest) and also programmed almost the same in the codeplug, except for the comment and the icon info.

Did you test with a radio you know can transmit APRS?

Its not a valid test unless you have a 'control' to compare with

[VK3KYY]

I will do a more thorough test later. I was w/ a friend yesterday who isn't a ham, so I didn't want to spend too much time fiddling w/ it. I already carried 3 HTs on my belt, and already looked like a dork .

Next I go out by myself, I will take out my Anytone D878UV, which is known to work for APRS TX. Worst case I will bring along my Kenwood D74A as well. I have enough radios to compare, just not enough time to try everything haha.

There were some problems in this release with APRS mainly if the Vias or destination were not correct, and potentially if your callsign is not input in upper case.

We've been working the APRS and other things for the last week to try to make sure its not possible to have an invalid APRS config which would generate invalid APRS packets.

And we will do another update soon.

[VK3KYY]

There were some problems in this release with APRS mainly if the Vias or destination were not correct, and potentially if your callsign is not input in upper case.

We've been working the APRS and other things for the last week to try to make sure its not possible to have an invalid APRS config which would generate invalid APRS packets.

And we will do another update soon.

I have almost identical codeplug on the RT3s and GD77, and the other 2 worked 2 nights ago, so I know the basic config is working. Just not on the RD-5R, and first I blamed it on the short stubby antenna from Retevis. Yesterday it was on a stock looking antenna (but can't tell from where anymore, as they all look the same: Baofeng alike).

I followed the example of the 2 popular threads here to make sure I have the correct settings . I used WIDE1-1 and WIDE2-1, and I am in an urban area w/ decent, although not great, APRS digipeaters and iGates here. My Anytone is often set to auto beacon and from time to time it's picked up by gateways, even though it's carried on my belt almost all the time (thus the antenna is blocked by my body, and the signal was absorbed as well.), depending on the area I am in. If I do it on a mobile antenna in my car, then the success rate will be better. I can certainly try RX it at home, but I thought a distance receiver is a better test, w/ more marginal signal strength. But worst case is I will test it at home w/ my D74A which has APRS RX or my D710A in my car.
(again, I didn't do a more thorough test only b/c of lack of time so far.)

OK.

I'll retest the RD5R

I did manage to transmit my local SDR Angel installation, but its possible that because the quality of the hardware in this radio is very low that perhaps it doesnt work on all RD5Rs


I'll retest my RD5R again today

[VK3KYY]

Update.

I just tested on my RD5R, albeit using a new as yet unreleased version of the firmware, and it worked fine to my local SDR Angel receiver

I currently can't find my SMA to SO239 to connect to my external antenna, becuase this radio uses the opposite sex SMD to the TYT radios

And I'm too far from the nearest APRS network receiver to be able to access it on a rubber duck antenna