ESP32APRS_T-TWR do not decode APRS received via RF

[px5e9142]

Hi,

I recently put on the air a T-TWR VHF and it dont't decode any APRS transmitions in RF. I can heard the signal from its speaker, but it do not send to APRS.fi any stations. I have tried iGate and DiGi modes and received the same results. On the dashboard via web interface do not show any statation too.

Antonio 73 PU5PWM

[boeningc]

Having the same issue. Have tried using my AnyTone HT as well as OTA signals that have been heard. Nothing seems to decode. Have tried narrow and wide as well as compression on/off. No Rx packets.

Tx is working great!

[nakhonthai]

Factory reset and reconfig again. Default config it can received and decode to display on OLED. https://www.youtube.com/shorts/Ue8LRRpVCSE?feature=share

[boeningc]

Thank you for the reply. Still do dice.

https://photos.app.goo.gl/zHWcYf1LztC1RShM9

From: nakhonthai @.> Sent: Monday, January 15, 2024 7:17 PM To: nakhonthai/ESP32APRS_T-TWR @.> Cc: Charles Boening @.>; Comment @.> Subject: Re: [nakhonthai/ESP32APRS_T-TWR] ESP32APRS_T-TWR do not decode APRS received via RF (Issue #15)

EXTERNAL EMAIL - Use caution when opening attachments, clicking links, or sharing sensitive information.

Factory reset and reconfig again. Default config it can received and decode to display on OLED. https://www.youtube.com/shorts/Ue8LRRpVCSE?feature=share

- Reply to this email directly, view it on GitHubhttps://github.com/nakhonthai/ESP32APRS_T-TWR/issues/15#issuecomment-1893010005, or unsubscribehttps://github.com/notifications/unsubscribe-auth/ABQNB22IZCDN44T3BLV6PYTYOXWLBAVCNFSM6AAAAABBONS2M2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTQOJTGAYTAMBQGU. You are receiving this because you commented.Message ID: @.***>

[px5e9142]

Thank you for the reply. Still do dice. https://photos.app.goo.gl/zHWcYf1LztC1RShM9 From: nakhonthai @.> Sent: Monday, January 15, 2024 7:17 PM To: nakhonthai/ESP32APRS_T-TWR @.> Cc: Charles Boening @.>; Comment @.> Subject: Re: [nakhonthai/ESP32APRS_T-TWR] ESP32APRS_T-TWR do not decode APRS received via RF (Issue #15) EXTERNAL EMAIL - Use caution when opening attachments, clicking links, or sharing sensitive information. Factory reset and reconfig again. Default config it can received and decode to display on OLED. https://www.youtube.com/shorts/Ue8LRRpVCSE?feature=share - Reply to this email directly, view it on GitHub<#15 (comment)>, or unsubscribehttps://github.com/notifications/unsubscribe-auth/ABQNB22IZCDN44T3BLV6PYTYOXWLBAVCNFSM6AAAAABBONS2M2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTQOJTGAYTAMBQGU. You are receiving this because you commented.Message ID: @.***>

Same here...

[px5e9142]

https://github.com/nakhonthai/ESP32APRS_T-TWR/issues/20#issuecomment-1893005396 I have tried this and now it works!!!!!!!

[Stingry165]

I did the reset and added band pass filter, TX time slot 2000 and 300ms delay and it worked after a coule of tries.

[Basti77]

I am experiencing the same issue as described here. The device transmits and receives audibly, but it does not decode anything. We had two devices lying next to each other set to the EU APRS frequency of 144.8 MHz. You can hear the signal, but it is not processed. I have tried the EEPROM reset mentioned above and also the option with the bandpass filter. Both devices are deaf in terms of reception. Additionally, mine does not produce a clean signal. Only a single data packet has been received by me despite being 50 meters away from the club station. DO5SKL-8

[Basti77]

I think I've found the problem. There are differences in the devices (the RF module). I had to set the frequency deviation to 3.5K on my end to be able to decode the signal at all.

[nakhonthai]

Yes, you need to check parameter.

• RF Frequency shift
• Band width (10-12.5KHz)
• Deviation (FM mod 3.5KHz)

[boeningc]

Very weird. I'm still not receiving on the device. I think @Basti77 was talking more about Tx from the device and receiving on another device. I'm using an Anytone HT and Tx APRS 144.390. I'm decoded by other devices no problem but with the T-TWR device running this code, nothing ever decodes. I can hear it in the audio on the device but nothing on the dashboard.

I have a second device but have not tried connecting it yet. I did try the BPF but that didn't help.

STATISTICS

PACKET RX: | 0 PACKET TX: | 0 RF2INET: | 0 INET2RF: | 0 DIGI: | 0 DROP/ERR: | 0/0

[boeningc]

I did a bit more testing. No 3.5KHz offset needed for me. I Tx data is still working great. Here's what it looks like on the scope in SDRangel. Great decodes on Tx. My Anytone decodes the Tx just fine. It's just that dang Rx that's not working right. :)

I do note that the Tx off the unit is pretty wide compared to the Anytone. I did try both narrow and wide for my Tx on the Anytone but neither was decoded on the ESP32APRS_T-TWR device.

[Basti77]

I'm just a beginner when it comes to radio technology, but maybe the bandwidth is too wide? Perhaps it would help to reduce the Mark_Freq and Space_Freq? The numerical values are actually just as they should be in theory. As for the other parameters, I can only guess their functions.

Our club also noticed that the frequencies weren't quite right. We've slightly shifted the TX/RX frequency downward, and now we're being received better by other devices. The TWR devices are also communicating better with each other now. Mine is currently on version 0.3d. (self-built)

Oh, and the included antenna is complete garbage.

[boeningc]

@Basti77 Interesting. I'll have to try that. I did notice in the SDR that the TWR seems to start a bit high then shift towards the left during the transmit cycle.

I am running the TWR on narrow but it seems to be coming out wide when compared to my HT.

I also note that if I try high power the device completely locks up after 2x transmits. On low power, our local APRS I-Gate is picking me up about 14 miles away. That's pretty good! :)

[dronesnapshot]

Having the exact same issues as everyone else, zero RX using the T-TWR Plus VHF, I hear the noise but nothing decoded. My Yaasu FT3 sitting beside it decodes it just fine.

TX is working sweet with zero issues, got some really good range in tracker mode when mobile.

Have tried it both on provided antenna and my home base antenna that works very well nothing, its completely deaf.

Things I have tried so far. -Factory reset the unit after firmware load, Done this about 3 times so far. -Set all the parameters, frequencies for Australia & call signs -Turned on filters. -reverted back to factory firmware and tested the RX and it is working sweet.

It a very cool project, just wish I could get the RX decode to work.

VK5URD

[Basti77]

Try setting the TX frequency a little lower and the RX frequency a little higher - you'll have to try it out for yourself. in my case it's 100Hz This works quite well for me (I use the latest version 0.3d) although the overall performance of the system is below a simple Lora module, but there is certainly still room for improvement. D05SKL

[dronesnapshot]

Try setting the TX frequency a little lower and the RX frequency a little higher - you'll have to try it out for yourself. in my case it's 100Hz This works quite well for me (I use the latest version 0.3d) although the overall performance of the system is below a simple Lora module, but there is certainly still room for improvement. D05SKL

Cheers for the idea. Spent a few hours this morning stepping through 145.1750 to .1850 in .0050 increments while manually keying up an APRS beacon and only managed to get 1 RX. Reboot between each increment.
This is just with the release V0.3

Might be worth just self-building 0.3d.

Starting to think I may just have a dud SA868_VHF.

Cheers

VK5URD

[VK1MIC]

I’m in the same boat. On Mon, 26 Feb 2024 at 11:03, dronesnapshot @.***> wrote:

Try setting the TX frequency a little lower and the RX frequency a little higher - you'll have to try it out for yourself. in my case it's 100Hz This works quite well for me (I use the latest version 0.3d) although the overall performance of the system is below a simple Lora module, but there is certainly still room for improvement. D05SKL

Cheers for the idea. Spent a few hours this morning stepping through 145.1750 to .1850 in .0050 increments while manually keying up an APRS beacon and only managed to get 1 RX. Reboot between each increment. This is just with the release V0.3

Might be worth just self-building 0.3d.

Starting to think I may just have a dud SA868_VHF.

Cheers

VK5URD

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[dronesnapshot]

TX is not looking to bad, set on APRS, little off but not bad.

[Basti77]

In the SDR screenshot you can see that the frequency always drifts upwards.

I don't know if you can "tune" the PLL via software. I only have the basics from my HAM exams in mind.

I can't imagine the temperature now with the short transmission bursts. then more voltage regulation would also explain why the device hangs up at max transmission power. It would not be the first project where an additional capacitor has to be soldered in. but where? at VCC of the HF module?

[dronesnapshot]

In the SDR screenshot you can see that the frequency always drifts upwards.

I don't know if you can "tune" the PLL via software.

I only have the basics from my HAM exams in mind.

I can't imagine the temperature now with the short transmission bursts. then more voltage regulation would also explain why the device hangs up at max transmission power.

It would not be the first project where an additional capacitor has to be soldered in. but where? at VCC of the HF module?

Possibly some of the hard coded config could be added to the menu under something like advance radio where u could tune it a bit.

I see this project has had a few edits, hopefully development is continued, it a fantastic APRS transmitter.

[imagesafari]

Same issue for me. I hear lots of packets via the speaker, but none are being decoded.

[agentmanderplex]

There are two hardware revisions, 2.0 and 2.1. https://openrtx.org/#/hardware/ttwrplus

According to OpenRTX, v2.0 does not have the AF out from the SA868 connected to a pin on the ESP32 board, making decoding impossible. V2.1 is relatively new, newer than this project, which doesn’t make sense.

what pin on the ESP32 is expected to receive the audio from the SA868? If this is true, then I imagine a jumper from the speaker to the appropriate header pin is possible… For APRS, the audio feature of a walkie talkie is pretty useless anyway.

[Basti77]

According to OpenRTX, v2.0 does not have the AF out from the SA868 connected to a pin on the ESP32 board, making decoding impossible. V2.1 is relatively new, newer than this project, which doesn’t make sense.

what pin on the ESP32 is expected to receive the audio from the SA868? If this is true, then I imagine a jumper from the speaker to the appropriate header pin is possible… For APRS, the audio feature of a walkie talkie is pretty useless anyway.

but that does not explain the different performance when sending. Basically, the devices send and receive.

or does "nothing come out" of your device when you look at the signal on the SDR? D05SKL

[agentmanderplex]

The t-twrs I have are definitely transmitting aprs over RF, but it will not decode received RF packets. You can hear them over the speaker but they’re never processed. INET/APRS-IS packets are processed just fine.

[boeningc]

Sounds like the RF output only goes to the speaker and not an input on the ESP32.

[imagesafari]

I just got mine, so I am guessing that it's 2.1?

[dronesnapshot]

Sounds like the RF output only goes to the speaker and not an input on the ESP32.

It's strange, it must go to the ESP32 on v2.1 as it decoded an APRS just once. Code must just need some tweaks for this 2.1 version which I suspect I own.

[VK1MIC]

I am playing with the RX freq to be like an offset, I have not used the dbv ratings before for audio. What is a 'good' value? I am around -16.1 for most packets.

[lyusupov]

Be aware that

• effective (approx.) from September, the LilyGO have fixed issue with wrong value of R22 resistor.
  it may still be shown as 4.7K on the schematic file but one should actually read it as 47K instead

Inspect that your T-TWR Plus board uses 47K for the R22 value. If it is true - it is recommended to NO longer use 11dB as ADC attenuation here:

For recently manufactured boards it is recommended to use 0 dB attenuation value.

Older boards (manufactured before September) can be fixed by the R22 replacement:

Read this thread for more details: https://github.com/erstec/APRS-ESP/discussions/29#discussioncomment-7276102

[UnderwaterHockey]

After numerous re-flashes, testing various volume and squelch levels, trying to adjust the rx frequency until I get the best signal, I still can not get the unit to show any received traffic.

[smfichera]

Also having the same issues. It will not decode the received traffic over RF. I just got the T-TWR and flashed it. I looked at this thread and tried all of the suggestions. No Luck.

[dboggny]

Just uploaded .4. Decodes occasionally then stops. Also the access point is working now.

[imagesafari]

Flashed .4 - still cannot get it to decode any packets

[imagesafari]

Actually, it looks like it IS decoding some packets.. I'm not sure how consistently. Very exciting!

[imagesafari]

I agree, it decodes a few packets and then stops decoding.

[dboggny]

With the squelch open and audible packets coming in it doesn’t decode. If I’m standing next to it with my Kenwood radios it works.

[lyusupov]

APRS Rx example

Test conditions

1) Software version 0.4 2) Board: LilyGO T-TWR Plus V2.0 , very first production batch ( June 2023 , R22 = 4.7 KOhm ) 3) Firmware: "stock" NiceRF V1.0 4) Antenna Diamond A144S5

5) Radio settings

6) Speaker is OFF

7) Dash board

8) Distance

[dboggny]

Thank you Lyusupov. I was able to get similar results using a J Pole with squelch open and volume on 2. My speaker is connected, I like the sound of static in the morning.

[UnderwaterHockey]

New firmware with the settings @lyusupov mentioned is working for me so far, it's actually rx'ing packets. I am seeming reboots every 2-3 hours though.

[dboggny]

New firmware with the settings @lyusupov mentioned is working for me so far, it's actually rx'ing packets. I am seeming reboots every 2-3 hours though.

I don’t know why it only works with my Ed Fong J Pole antenna. I have tried both diamond and comet HT antennas and while I hear packets, none decode while my Kenwood d74 decodes them. Only works with the J Pole. I guess I’m expecting too much from a $50 development board.

[lyusupov]

@dboggny have you measured R22 resistance value of your particular T-TWR board with a multimeter ? If is 47K Ohm -- you need a custom built ESP32APRST-TWR firmware (from the source code)_ with ADC1 attenuation set to 0dB.

Another option is to try Arctic Tracker firmware for the T-TWR V2.0

[dboggny]

As far as measuring resistance value, I am embarrassed to say I am really just an operator and don’t know how to do that. Same for building from source code. If there is a tutorial for how to do it I’d give it a go. I have to Lilygo boards and wouldn’t mind blowing one up trying something new.

I can try arctic tracker I think. I’ve looked at it before.

[banshee1971]

Got same issues as everyone. It sent packet that I can decode with other devices, but received nothing, even when i transmit APRS packet fiew meters away from the T-WRT.

Then i reset the unit (someone post it) and now, i receive and decode packet! But the moment i enable DIGI, can't decode APRS packet anymore. But when i disable DIGI, all working again (iGate).

[VK1MIC]

Be aware that

• effective (approx.) from September, the LilyGO have fixed issue with wrong value of R22 resistor. it may still be shown as 4.7K on the schematic file but one should actually read it as 47K instead

Inspect that your T-TWR Plus board uses 47K for the R22 value. If it is true - it is recommended to NO longer use 11dB as ADC attenuation here:

For recently manufactured boards it is recommended to use 0 dB attenuation value.

Older boards (manufactured before September) can be fixed by the R22 replacement:

Read this thread for more details: erstec/APRS-ESP#29 (comment)

I downloaded visual studio code, and copied the git repo. I held boot and pressed RST the released RST then Boot I edited those files and then hit build, follow by upload, but each time it pushed the build to the device, the OS didnt update.. it remained at the previous verion.

[tompython-ncg]

settings as lyusupov mentioned, digi mode only, speaker disconnected from socket. Rubber antenna. Newest firmware 0.4.