Important: These forums are for discussions between SkyDemon users. They are not routinely monitored by SkyDemon staff so any urgent issues should be sent directly to our Customer Support.

Autopilot + COM freq. over BT to RS232


Author
Message
ALSL-Flyer
A
Junior Member (14 reputation)Junior Member (14 reputation)Junior Member (14 reputation)Junior Member (14 reputation)Junior Member (14 reputation)Junior Member (14 reputation)Junior Member (14 reputation)Junior Member (14 reputation)Junior Member (14 reputation)
Group: Forum Members
Posts: 10, Visits: 1
maikmita - 1/6/2025 7:45:19 PM
maikmita - 1/6/2025 7:34:16 PM
Michael Hoffmann - 1/6/2025 6:58:52 PM
maikmita - 1/6/2025 3:02:49 PM
Michael Hoffmann - 1/4/2025 4:36:32 PM
bsdchapman - 1/4/2025 2:41:07 PM
Michael Hoffmann - 12/22/2024 8:16:04 PM
Dortro - 12/21/2024 7:53:40 AM
Hi Michael,Thank you very much for both answers, this is very helpful!I was thinking to wire my BT580 to the KRT2 plug, following the diagram for connecting the remote. Your second suggestion sounds very good and, indeed, clean. Would it be expensive?My problem now is that my BT580 ls not detected by SD! I am mailing with Support about it.One of those things, it should detect the device almost immediately, but it does not…Again, thank you!

Hello dear community,
the prototype of a TQ KRT2 BLE PnP (PlugAndPray Smile) adapter is ready. 
The advantage of this dongle is that it is powered by the device itself.
You don't need any additional wiring. The size is (40 x 45 x 17) mm. Unfortunately I can't make it any smaller.
Simply plug this dongle between your existing cables - and you're done.
Yes, the correct mounting brackets are included with the final version...
I don't have them in stock yet. The screws aren't the right ones either...but that will be solved too.


It is important that the electronics work in this small space. She does.
Unfortunately I don't have a KRT2 to test and am therefore looking for a willing tester.
Is there anyone with a TQ KRT2 who can test this dongle? I'm looking for a tester in Germany, preferably in the Berlin area.

If you can and want to help here, send me a PM.

Can’t help with basic testing (I’m UK based), but would be interested in this as a beta or finished product.  The KRT2 is the worst UX I’ve ever come across for a radio!

Also wonder if you would be able to create a package with just 12v / Gnd / Tx / Rx interface - maybe 2-3 RS232 outputs, so we can fit one box, behind the panel, plumbed straight into the electrics (no 5v/usb), with multiple data outputs to run to radios, autopilot, and anything else that would be benefit from a one way data stream?

Hello Bsdchapman,

thanks for your answer. I have now received a KRT2 from a colleague and was able to test the adapter. Yes, it works. The KRT2 adapter simply plugs between the existing wiring and the radio and is powered by the radio's power supply itself. 
No additional wiring or mechanical work required. Something like PnP (Plug and Pray) ;-)).

Look here:

At pin 13 of the connector, the RS-232 output is available for other devices (true V24 voltage) such as autopilots, AV-30, other radios or whatever else comes along. The adapter works in the voltage range of 8 - 30 V and is short-circuit proof.

Is that what you're looking for? Or do you really want a separate box with its own power supply and multiple outputs?

Regards
Michael

Hello
 Michael,

very interesting solution. I am using the Krt2 in combination with the Air Control Display from Air Avionics, which functions as a remote control for the KRT2.

I am wondering if your solution would be able to operate in between those two devices or if I would need to place a switch in between to decide whether the BT or the air control display is connected to the KRT2?

Best regards from the south of Germany,
Maik



Well, the first answer is NO - but it depends...
The KRT2 uses an RS232 interface for communication. RS232 is by definition a point-to-point connection, not a bus system.
This standard can be extended to one transmitter and N receivers without any problems, as long as the output of the transmitter is not overloaded. This is called multi-drop. For us this means: A BLE module sends to several RX devices via TX without problems.

It doesn't work the other way around. Multiple transmitters cannot transmit to one receiver, for 2 reasons: 
1.) The outputs of the transmitters work electrically against each other, which is like a short circuit.
2.) If both transmitters transmit at the same time, the data becomes unreadable (corrupted).

But no problem without a solution or at least a workaround...
The simplest solution is 2 diodes. These are connected to the TX lines to prevent a short circuit. This means that the V24 levels are no longer 100% correct, but it usually works.
You can improve the result with a pullup resistor. But I wouldn't use this DIY solution for an avionics device.

And here comes the solution:
The KRT2 BLE adapter from SD-Link mentioned above has 2 independent RS232 channels internally. Normally only one RS232 channel is used to output the received BLE command to the radio and to pin 13 of the outside connector. But that can be reprogrammed, to use pin 13 as an isolated RS232-input as well.

Then both signals are ORed with the correct V24 levels and passed on to the radio.
You just have to make sure that both sources are not transmitting at the same time. Does the Air Control Display transmit constantly or only when the frequency changes? SD is transmitting only, when a frequency is changed.

Best regards from the east of Germany
Michael



Michael,
thanks a lot for this detailed answer.
Right now I do not know if the air control display transmits constantly. But I try to investigate in the documentation.
What I know is, that the communication with the Krt2 is bidirectional because changes on the KRT2 will also be displayed on the air control display. So RX and TX are both used from my point of view.

I am not sure if I got you correct: you mean when reprogramming the adapter to use pin 13 as a separate RS232 chanel it will receive the commands from the air control display on pin 13 and forwards it on the other chanel to the pin of the KRT2?

Regards
Maik



I am not sure, but for me it sounds like it is only transmitting when a change has been performed.

Regards Maik


Hello Maik, some hints from my side. 
hint1: I have in my plane a KRT2 which works perfect with the F2R-Module. F2R has Datatransfer only to the radio not reverse. What I know is, that Becker Radio needs both directions.
hint2: I know somebody who was successful to link ACD and KRT2 and F2R.  The break through came with configuration "GTR225" on ACD side and SD-side... even its a KRT2. 
hint3: the datastream for the radio comes via ACD connector1 pin2 (in his case from F2R-device, but that shouldn´t matter, irxon should also work) 
hint4: ACD-Softwareversion should not be older than 45
hint5: Baudrate must be set to 9600Baud

Even I personally do not own a ACD, I hope this helps.... regards Ulli

Michael Hoffmann
Michael Hoffmann
Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)
Group: Forum Members
Posts: 33, Visits: 10
Michael Hoffmann - 1/4/2025 4:36:32 PM
bsdchapman - 1/4/2025 2:41:07 PM
Michael Hoffmann - 12/22/2024 8:16:04 PM
Dortro - 12/21/2024 7:53:40 AM
Hi Michael,Thank you very much for both answers, this is very helpful!I was thinking to wire my BT580 to the KRT2 plug, following the diagram for connecting the remote. Your second suggestion sounds very good and, indeed, clean. Would it be expensive?My problem now is that my BT580 ls not detected by SD! I am mailing with Support about it.One of those things, it should detect the device almost immediately, but it does not…Again, thank you!

Hello dear community,
the prototype of a TQ KRT2 BLE PnP (PlugAndPray Smile) adapter is ready. 
The advantage of this dongle is that it is powered by the device itself.
You don't need any additional wiring. The size is (40 x 45 x 17) mm. Unfortunately I can't make it any smaller.
Simply plug this dongle between your existing cables - and you're done.
Yes, the correct mounting brackets are included with the final version...
I don't have them in stock yet. The screws aren't the right ones either...but that will be solved too.


It is important that the electronics work in this small space. She does.
Unfortunately I don't have a KRT2 to test and am therefore looking for a willing tester.
Is there anyone with a TQ KRT2 who can test this dongle? I'm looking for a tester in Germany, preferably in the Berlin area.

If you can and want to help here, send me a PM.

Can’t help with basic testing (I’m UK based), but would be interested in this as a beta or finished product.  The KRT2 is the worst UX I’ve ever come across for a radio!

Also wonder if you would be able to create a package with just 12v / Gnd / Tx / Rx interface - maybe 2-3 RS232 outputs, so we can fit one box, behind the panel, plumbed straight into the electrics (no 5v/usb), with multiple data outputs to run to radios, autopilot, and anything else that would be benefit from a one way data stream?

Hello Bsdchapman,

thanks for your answer. I have now received a KRT2 from a colleague and was able to test the adapter. Yes, it works. The KRT2 adapter simply plugs between the existing wiring and the radio and is powered by the radio's power supply itself. 
No additional wiring or mechanical work required. Something like PnP (Plug and Pray) ;-)).

Look here:

At pin 13 of the connector, the RS-232 output is available for other devices (true V24 voltage) such as autopilots, AV-30, other radios or whatever else comes along. The adapter works in the voltage range of 8 - 30 V and is short-circuit proof.

Is that what you're looking for? Or do you really want a separate box with its own power supply and multiple outputs?

Regards
Michael



Thanks to bsdchapman, the fleet has received a new member - the GENERIC-E adapter.

This is a very small Bluetooth BLE adapter for SkyDemon that you can wire yourself.
It has a 9-pin standard V24/RS323 pinout.
It can do MultiDrop, supply voltage 8 - 28 V, and glows in the dark - that was nonsense.
But the rest is true 32 x 32 mm footprint. M3 or 4/40 UNC screws. Please specify when ordering.

Diplomat
D
Forum Newbie (4 reputation)Forum Newbie (4 reputation)Forum Newbie (4 reputation)Forum Newbie (4 reputation)Forum Newbie (4 reputation)Forum Newbie (4 reputation)Forum Newbie (4 reputation)Forum Newbie (4 reputation)Forum Newbie (4 reputation)
Group: Forum Members
Posts: 1, Visits: 9
Hello, first of all, Michael's BLE adapter for the Becker works great. While I'm not lazy when it comes to soldering, the adapter is ultimately a quick and very well-thought-out solution that saved me the trouble of gathering all the components. The frequency switching works perfectly. His website is: sdlink.de

Now, another question: I'm considering connecting Skydemon to my Stratux via BLE in the future since I occasionally experience disconnects with automatic reconnects when using WiFi-Direct. Before I keep experimenting: Can Android 14 with Skydemon (latest beta) actually maintain two BLE connections simultaneously—one to the BLE adapter for frequency switching and one to the Stratux? Has anyone already tested this?
Michael Hoffmann
Michael Hoffmann
Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)Too Much Forum (135 reputation)
Group: Forum Members
Posts: 33, Visits: 10
Diplomat - 1/18/2025 12:55:32 PM
Hello, first of all, Michael's BLE adapter for the Becker works great. While I'm not lazy when it comes to soldering, the adapter is ultimately a quick and very well-thought-out solution that saved me the trouble of gathering all the components. The frequency switching works perfectly. His website is: sdlink.de

Now, another question: I'm considering connecting Skydemon to my Stratux via BLE in the future since I occasionally experience disconnects with automatic reconnects when using WiFi-Direct. Before I keep experimenting: Can Android 14 with Skydemon (latest beta) actually maintain two BLE connections simultaneously—one to the BLE adapter for frequency switching and one to the Stratux? Has anyone already tested this?

Thanks for the praise, I'm very pleased.
Now to your question: I operated 2 BLE adapters in parallel for 24 hours in the test. One adapter for the Becker AR6201 and one for the KRT2. Setting the frequencies works simultaneously on both devices, even though they are 2 separate BLE receivers.
I haven't tried it with a Stratux yet, but I think it will work.

GO

Merge Selected

Merge into selected topic...



Merge into merge target...



Merge into a specific topic ID...




Reading This Topic

Login

Explore
Messages
Mentions
Search