T-echo with audio warnings (buzzer or speech)?

[Rens Peeters]

I like to use a softRF dual protocol solution to complete my DIY vario for hanggliding. I will use a Android phone to run xc-soar, XCtrack or any other suggested software. The idea is to have audio collision warning, from the data provided from SoftRF. It seems that XC-soar or XCtrack only shows FLARM data on screen. I wonder if someone found a solution to also have waring messages over the speaker of an Android device? 

I learned already about the stand-alone solution with a T-beam with separate display and speaker. But I also like the T-echo option as it is very compact and is a ready made stand-alone solution, already combined with a small display. Perfect for Hanggliding or Paragliding. Except, if i understood correctly, it is missing buzzer support in SoftRF MB. So actually I am hoping for upcoming support, to use a buzzer directly connected to the T-echo/ t-echo plus, or any other ready made compact device with display.

I was hoping to find some advice here, to make a choice what to purchase. 

[Moshe Braner]

For just a buzzer, you can use a T-Echo-Plus, Thinknode M1, Thinknode M3 or T1000E - I am working on a version of my branch of SoftRF that will support all those models.  But if you already have a T-Echo, and plan to use XCsoar (or some other similar apps) running on an Android device which has its own speaker, XCsoar already does provide voice warnings.  The Oudie N promises to have that some day, but we've been waiting for years already...  Not sure about SeeYou Navigator, it is essentially the same as the Oudie N software.

[Rens Peeters]

Alright, that is good news! Thank you very much for your vast response and your work Moshe! I will dig deeper in the xc-soar settings. That is already a good solution, but a stand alone device give me more flexibility to use other flying software too. So great that you are working on a version for those devices! I will then go for the t-echo (plus) or Thinknode M1.Will the t-echo with a buzzer conected via an expansion board also be an option?

Op zaterdag 2 mei 2026 om 20:19:44 UTC+2 schreef Moshe Braner:

[Moshe Braner]

It will work if the expansion board's buzzer is supported by the software - I am not familiar with it.  I also have not tested with a T-Echo-Plus, but the code is based on Linar's which claims to support it.  If it doesn't work we'll find a way to make it work.  Then again, words such as "traffic, 3 O'Clock low" is much better than just a beep.

[Rens Peeters]

OK. Thanks for the advice. I agree speech messages will improve the experience, as you want to look out for the possible danger coming and not first finding out where it comes from. But I'm afraid, in my usecase, I will not be able to hear what is said when this message comes from a small speaker. While wearing a helmet together with wind noise it wil likely not work.  Thinking about it now, it would be a nice feature if the Bluetooth of the LoRa can be used to connect to a bluetooth headset and have SoftRF output speech messages over bluetooth. The FLARM data in that case must be transmitted an other way than over Bluetooth. I presume that is not a possibility at this time? My primary goal is to get SoftRF to work with eg. XC-soar, and have this software provide speech messages via a Bluetooth headset in my helmet, that is connected to the android phone. In addition there will be an alarm via the buzzer and a radar screen on the LoRa. To always have a fool proof, stand alone solution not relying on bluetooth connection and other apps. 

Will the code for the T-Echo-plus and Thinknode M1 be the same? Are there, or will there be, any advantages for the Thinknode over the T-echo plus, in your point of view? Except for the better standard antenna, the vibration motor , pressure sensor and the IMU on the T-echo-plus, I do not see much specification differences. With the Thinknode, on the other hand, you can switch off gps via a switch.

Op zondag 3 mei 2026 om 01:01:59 UTC+2 schreef Moshe Braner:

[Moshe Braner]

I have never actually held an M1 nor a T-Echo Plus, so can't say.  The GPS-off switch is not useful for our purpose, as we always want it on.  I don't see much point in either the pressure sensor nor the IMU (nor the vibration) but your needs may vary.  It will be the same binary to run on the T-Echo, T-E Plus, M1, M3 and T1000E - the code will detect at runtime which model it is running on.

[Adam Mościcki]

Coming back to the first question : can we connect T-Echo(MB174-transmiting Flarm/Fanet packets) with xctrack or xc-soar app ? 

- will the app display only current position of my tracker or will it display any other info from the tracker ?- like any warning ?

If the app is receiving any other data , not only the position, then there is a questin if the app can display that warning ot play a sound.

The other question is : can we connect T-Echo via BLE to the smartphone and what data is it sending ?

If it is sending something more than a position - like a warning, than I could preapare a small app that is playing a sound or even speaking " "traffic, 3 O'Clock low" . 

This way a smartphone can be used as an external speaker for T-Echo :)

[Moshe Braner]

I am not familiar with Xctrack, but XCsoar definitely shows the traffic and gives traffic warnings. Connection by BLE works.  The data flowing from SoftRF to the app is in the FLARM-standard format, i.e., $PFLAU and $PFLAA NMEA sentences (and a few more).

[Adam Mościcki]

Yes I checked my t-echo. it sends $PFLAU via BLE

questions :

- do you know any link with definition of FLARM sentences the softRF is sending ?

- I think there is a bug with BLE connection. I can connect via BLE only after reset of T-Echo. when I try to connect later, after a few minutes or disconnection , I can not connect via BLE. It looks like the T-Echo is ready for BLE connection only a few seconds after reset. Later it is not allowing any connection via BLE. 

maybe the BLE discovery should be kept for the whole time the T-Echo is running ?

[Moshe Braner]

For the BLE discovery issue, I hope others here that use the T-Echo more than I do can answer.  In the few cases I tried a BLE connection, it worked, and not just in the first seconds after reset.  But I have always found BLE to be tricky to configure.  Classic BT easier (but not supported by the T-Echo).  WiFi/UDP easier (same).  The T-Beam can do all of those (or even WiFi/TCP).  Generally I have heard that, for BLE, you do NOT want to "pair" your phone with the T-Echo, rather, ask the app (for example, XCsoar) to connect to it.

Regarding the PFLAU & PFLAA sentence documentation, it is here:

https://www.flarm.com/wp-content/uploads/2025/09/FTD-012-Data-Port-Interface-Control-Document-ICD-7.22.pdf

Of course, that is not a SoftRF document.  SoftRF tries to follow the official FLARM data protocol.  That is how what it sends out is understandable by apps and devices that were developed to handle FLARM data.