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maikmita - 1/6/2025 7:45:19 PM

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maikmita - 1/6/2025 7:34:16 PM

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Michael Hoffmann - 1/6/2025 6:58:52 PM

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maikmita - 1/6/2025 3:02:49 PM

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Michael Hoffmann - 1/4/2025 4:36:32 PM

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bsdchapman - 1/4/2025 2:41:07 PM

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Michael Hoffmann - 12/22/2024 8:16:04 PM

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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 ) 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

https://www.air-avionics.com/?wpdmpro=air-control-display-57-installationshandbuch&lang=de&wpdmdl=982&refresh=677c30e3e002b1736192227

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

Regards Maik