FrSky Taranis - OpenTX data flow diagrams - Page 3 - RC Groups
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Mar 05, 2016, 02:06 PM
Registered User
boomerwing's Avatar

Diagram for Edge Logical Switch Function


The OpenTX University material has a very good summary of the use of Logical Switch Functions if you are comfortable with Digital Logic. Having some experience with the basics of Digital Logic I particularly took an interest in the Edge Function. Attached is a summary of the edge function using timing diagrams to show what each version of the Edge Function does.
Also included is a Throttle Hold using two versions of the Edge Function as an example of how they are used.

I have used the OpenTX University jpg diagrams and attached my own timing diagrams as illustrations.
Have a look. Any suggestions for improvements or corrections are welcome.
Calvin
Last edited by boomerwing; Mar 06, 2016 at 04:05 PM.
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Mar 06, 2016, 09:45 AM
Froggy RC Pilot
LapinFou's Avatar
Good diagram.
Maybe you should use
- L1 instead Logical Switch Output
- V1 instead Selected Switch
- Add a horizontal axes named "time" with the corresponding value
- Add a vertical axes named "%" with the corresponding output value

I think this would help the understanding.
Mar 06, 2016, 04:13 PM
Registered User
boomerwing's Avatar

Thanks for the comments


Quote:
Originally Posted by LapinFou
Good diagram.
Maybe you should use
- L1 instead Logical Switch Output
- V1 instead Selected Switch
- Add a horizontal axes named "time" with the corresponding value
- Add a vertical axes named "%" with the corresponding output value

I think this would help the understanding.
Thanks for the comments, LapinFou. I have changed the diagrams as you suggest and yes, I think they are better now. Have a look.

As well, I have added a description of a Single Channel Rudder Only Escapement emulation as another example of the use of the Edge function. As they say in the textbooks, "An exercise for the reader". (I am glad they developed proportional control. I tried the Rudder Only on my Radian but was soon happy to get back to modern capabilities)
Regards, Calvin
Mar 06, 2016, 05:02 PM
Froggy RC Pilot
LapinFou's Avatar
Indeed it is much better. With this good visual, you can easily catch the concept.
Mar 06, 2016, 06:21 PM
ancora imparo
jj604's Avatar
The changed diagram is excellent, thanks. I like the single channel escapement emulation. However there are two significant enhancements needed with some additional logic:

1) random failure to actually operate or uncommanded operation caused by engine vibration at no predictable time.
2) the rubber band running down at an awkward moment.



We take the reliability of modern radio gear very much for granted.

John
Quote:
Originally Posted by boomerwing
Thanks for the comments, LapinFou. I have changed the diagrams as you suggest and yes, I think they are better now. Have a look.

As well, I have added a description of a Single Channel Rudder Only Escapement emulation as another example of the use of the Edge function. As they say in the textbooks, "An exercise for the reader". (I am glad they developed proportional control. I tried the Rudder Only on my Radian but was soon happy to get back to modern capabilities)
Regards, Calvin
Mar 06, 2016, 07:42 PM
Registered User
boomerwing's Avatar

More Edge and Rudder Only


Thanks John for your comment. Clearly you have more experience than I have. Back in the 60s my brother gave me a Jr. Falcon to build. Dad bought us a Citizenship 5 Regenerative Rx and I bought the simplest Escapement. (I should have bought the next more expensive one.) I built a Transister Tx and could never get the system to work. Much later, in a radio lab I put the RX on a signal generator and found that it would tune to 32 MHz, not 27MHz. No wonder it did not work. So I never got to experience the situations you feel could be added to the functions.
Anyway. I will also post the eepe for your amazement, wonder and convenience.

There is a second Rudder Only escapement Emulation as well. Pull SH\/ once, go one way. Pull it again, go the other way. You do have to arm it by moving the aileron stick fully left or right to initialize it. Of course, I leave the analysis and understanding of its working to the reader.

Warning: Trying to use the SH Momentary Switch with the mouse in Companion is not as easy as using it in the Taranis. You can easily double click the switch on the Taranis but getting the second click in in time in Companion is not as easy with the mouse.

I hope you can have a bit of fun with these.

Calvin
Last edited by boomerwing; Mar 06, 2016 at 09:27 PM. Reason: Warning added
Mar 07, 2016, 12:34 AM
ancora imparo
jj604's Avatar
And for a real challenge:

Press and Hold = Right
Press, Release, Press and Hold = Left
Press, Release, Press, Release, Press and hold for 1 second, Release = Motor speed change toggle

If I recall there was even an escapement that added
Quick blip = Up elevator

Timing of the release portion was critical and flying a single channel equipped with one of these Compound Escapements was more like conducting a recalcitrant drunk orchestra than piloting.

I watched someone do it once - it was beyond my skills. By the time I figured out where I was in the sequence I would have hit the ground or flown out of range - which wasn't all that far if you weren't careful with the tuning! And adding a Regenerative receiver to the mix was really inviting Mr Murphy around..

Now we have folks complaining that the OpenTX software is too complex and has too much functionality.

Apologies to Lapin Fou for drifting off topic but this is an interesting thread. I have printed out both the OpenTX flow diagrams and the Logic Switch diagrams and will be sharing with the other Taranis owners at the club.

Thanks

John


Quote:
Originally Posted by boomerwing
Thanks John for your comment. Clearly you have more experience than I have. Back in the 60s my brother gave me a Jr. Falcon to build. Dad bought us a Citizenship 5 Regenerative Rx and I bought the simplest Escapement. (I should have bought the next more expensive one.) I built a Transister Tx and could never get the system to work. Much later, in a radio lab I put the RX on a signal generator and found that it would tune to 32 MHz, not 27MHz. No wonder it did not work. So I never got to experience the situations you feel could be added to the functions.
Anyway. I will also post the eepe for your amazement, wonder and convenience.

There is a second Rudder Only escapement Emulation as well. Pull SH\/ once, go one way. Pull it again, go the other way. You do have to arm it by moving the aileron stick fully left or right to initialize it. Of course, I leave the analysis and understanding of its working to the reader.

Warning: Trying to use the SH Momentary Switch with the mouse in Companion is not as easy as using it in the Taranis. You can easily double click the switch on the Taranis but getting the second click in in time in Companion is not as easy with the mouse.

I hope you can have a bit of fun with these.

Calvin
Mar 07, 2016, 01:04 PM
60 years of RC flying
Daedalus66's Avatar

FrSky Taranis - OpenTX data flow diagrams


There is a single channel emulator that does what John describes, but with modern radio equipment. So you have a simple little box with one button and an on/off switch. Inside is an FrSky module and 9v battery.

Minor corrections on John's account. Quick blip controlled motor speed, via a second escapement (sometimes clockwork). To get "kick up elevator" you pressed three times, then held the button. This was a feature of the main escapement, not a separate one.

With the right model, flying single channel is really quite easy. I have a FlyZone FlyLite, a 36" light weight high wing model with ample dihedral. Except for being foam, electric and having modern proportional radio gear, it's much like the models we flew RC in the 50s and early 60s. The key thing is that it flies slowly and is highly stable. The radio just interrupts its natural progression.

My 7-year old grandson, who learned to fly this model with DX4e, had no problems when I gave him the one-button transmitter with which to control it.

Keep in mind that this was advanced technology for its time. My first RC model had a rubber powered escapement driving just rudder. Press and hold gave turn, but whether it was left or right depended on the last command. So to turn right, you pressed and watched. If it turned left, you released the button and pressed again. Of course, what you tried to do was remember what you had done last.

It sounds tricky, but on my very first successful RC session, I was able to make half a dozen short flights, taking off unassisted and landing back on the runway right side up. The model knew how to do this, as I had flown it free flight for a whole year before installing the radio! My contribution was just to steer it to the right place in the sky and point it at the runway.

Sorry about the excursion into nostalgia. Here's more for those who are interested:

http://www.singlechannel.co.uk
Last edited by Daedalus66; Mar 07, 2016 at 01:09 PM.
Mar 07, 2016, 01:53 PM
Registered User
JMP_blackfoot's Avatar
Quote:
Originally Posted by jj604
And for a real challenge:

Press and Hold = Right
Press, Release, Press and Hold = Left
Press, Release, Press, Release, Press and hold for 1 second, Release = Motor speed change toggle

If I recall there was even an escapement that added
Quick blip = Up elevator

Timing of the release portion was critical and flying a single channel equipped with one of these Compound Escapements was more like conducting a recalcitrant drunk orchestra than piloting. ...
Check this thread for a more complete view of what can be accomplished with OpenTx in the field of vintage flying emulation, escapement as well as pulse proportional :
http://www.modelflying.co.uk/forums/...s.asp?th=98671

Also :
https://db.tt/nPm5iqep
(Please read the readme file for explanations.)
Mar 07, 2016, 07:30 PM
Registered User
boomerwing's Avatar
Quote:
Originally Posted by LapinFou
Indeed it is much better. With this good visual, you can easily catch the concept.
I'm sorry, LapinFou. I was not trying to hijack your thread with my example code. The intent was just to illustrate the use of the Edge function in a fun way.
Regards
Calvin
Mar 08, 2016, 03:34 AM
Froggy RC Pilot
LapinFou's Avatar
Quote:
Originally Posted by boomerwing
I'm sorry, LapinFou. I was not trying to hijack your thread with my example code. The intent was just to illustrate the use of the Edge function in a fun way.
Regards
Calvin
Sorry about what? This post concerns diagrams which explain how OTX is working. So, your documentation perfectly fit this topic.
Mar 08, 2016, 12:42 PM
Registered User
Boomerwing - thank you.
Still have so much to learn about more basic functions (more precisely - the possible combinations), but thanks to pointing out the power of this (edge).
Mar 09, 2016, 10:05 AM
Registered User
boomerwing's Avatar
Quote:
Originally Posted by Darko FC
Boomerwing - thank you.
Still have so much to learn about more basic functions (more precisely - the possible combinations), but thanks to pointing out the power of this (edge).
Thanks you, DarkoFC.
I have started to put together an introduction to the Logical Switches. My mind is almost overwhelmed by the possible combinations but the basics are simple. Hopefully a first try very soon.
Calvin
Mar 09, 2016, 11:29 AM
Registered User
ridgerunr's Avatar
Excellent resources guys. Very well done!

Thank You!

One remaining mystery for me is the "sticky" logic switch - if someone could provide an explanation and example, this would be very helpful.

Thanks again!
Mar 09, 2016, 12:35 PM
Froggy RC Pilot
LapinFou's Avatar
Thanks!!


By the way, I updated the first post. I added the following message:
Quote:
See also boomerwing's diagram:
Diagram for Edge Logical Switch Function