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twin turbine RPM

Posted: Mon Sep 14, 2020 7:31 am
by michel49
In order to synchronize the motors of my A10 twin turbine I need to measure the RPM by the way of the brushless sensors of my FrSky gear. Is it possible to link and display two sensors -ID ?- on my PRO ?

MP

Re: twin turbine RPM

Posted: Mon Sep 14, 2020 7:09 pm
by MikeB
Are you using HUB or SPort telemetry? What RPM sensors?
If SPort, you would need to change the appId (application Id) of one of the sensors.

Mike

Re: twin turbine RPM

Posted: Tue Sep 15, 2020 7:40 am
by michel49
I use Sport and brushless RPM sensors; I understand I need to change the ID of one of the sensors (howto ?) but I have only one RPM display in ERsky9X

MP

Re: twin turbine RPM

Posted: Tue Sep 15, 2020 10:45 am
by MikeB
To change the physical ID of a sensor, go to www.er9x.com, and download the script "FrSky Sport Change Physical ID". Connect just one sensor to the Rx, power all on, then run the script. You should then be able to change the physical ID.

I will need to sort something to allow for the two values. This may be be possible by changing the appID, but I'll need to sort out how to change that, probably from a script. Without changing the appId, I'll need to modify erskyTx to handle the second physical ID as a separate telemetry value.

Mike

Re: twin turbine RPM

Posted: Tue Sep 15, 2020 2:09 pm
by jhsa
Custom telemetry field? Option to rename it? ;)

João

Re: twin turbine RPM

Posted: Fri Sep 18, 2020 10:06 pm
by MikeB
I've done some investigations and I should be able to provide a means of changing both the physical ID and the application ID from a script (or two).
I already have code available for erskyTx that handles multiple application IDs for the same sensor type. All FrSky sensors allow for 16 different application IDs for each sensor type, for example the RPM sensor if 0500 to 050F. My new code handles 0500 as normal, but treats anything else in the range 0501 to 050F as an unknown sensor and you may then use the sensors menu (under telemetry) to handle them.

It may take me a day or two to sort the script(s) for this.

Mike

Re: twin turbine RPM

Posted: Sat Sep 19, 2020 12:22 pm
by michel49
It would be helpful if FrSky give available a second range of RPM sensors labelled RPM2 and, of course, an other ID.

Re: twin turbine RPM

Posted: Sat Sep 19, 2020 12:37 pm
by Kilrah
Physical ID can be changed with the servo channel changer and is enough to distinguish sensors, has been used that way for 5 years in OpenTX. The ID can nowadays also be changed using scripts or FrSky's PC program if you have an appropriate interface cable, so it makes little sense to stock multiple versions.

Re: twin turbine RPM

Posted: Tue Sep 22, 2020 9:46 pm
by MikeB
I've posted a new test version of erskyTx that supports (as unknown sensors) FrSky sensors where the application ID is not the default value (ending in 0). I've also put up on www.er9x.com a script to allow changing the appId, currently just allowing the last digit to be 0 or 1. You may need to reload the site page to get the link to the script to appear.
All physical sensors do need to use different physical IDs, so to use two RPM sensors with this version of erskyTx, you will need to change both the physical ID and the application Id of the second sensor.
1. Connect the RPM sensor that needs changing as the only sensor on a bound Rx.
2. Use "ChangeId.bas" to change the physical ID.
3. Then use ChangeAppID.bas to change the application ID to 1 (currently only 0 or 1 are allowed).
4. Power cycle the receiver and sensor.
5. Now look in the Telemetry|Sensors menu. On the second page are up to four "unknown" sensor IDs, you should find one with a value of 0501. Beside that select a destination for the value, choose "CUS1". The raw RPM value from this sensor should now appear in the telemetry value CUS1 (for custom 1).
6. You will then need to use a SCALER to adjust this value for the number of poles in the motor to get the correct RPM value. The SCALER may be given a name e.g. RPM2.

Mike

Re: twin turbine RPM

Posted: Tue Sep 22, 2020 11:02 pm
by jhsa
This is cool Mike, thanks. Would it also work with 2 openXsensors reading the cells of 2 different 3s batteries?

João

Re: twin turbine RPM

Posted: Wed Sep 23, 2020 2:43 pm
by MikeB
erskyTx already handles the specific case of two LIPO cell sensors that are on different physical IDs, using the physical ID to tell which is which, so as long as the two OXS sensors are using different physical IDs (necessary), they work correctly. You must never have two sensors on the SPort bus with the same physical ID as each other.
There are two types of sensor, one just returns a single value for each application ID (e.g. vario, RPM), the other returns encoded data (e.g. FLVSS, GPS), where the value indicates the data content.

I'm considering if there is a "better" implementation of multiple sensors.

In passing, I see I've been working on er9x/erskyTx for over 9.5 years! At present, I'm having a bit of a break from "wall-to-wall" programming, just doing a few fixes and some things that interest me. I'll probably get back to doing more in a while!

Mike

Re: twin turbine RPM

Posted: Wed Sep 23, 2020 5:25 pm
by ReSt
Mike, could you, occasionally, push the latest modifications onto github ?

Reinhard

Re: twin turbine RPM

Posted: Thu Sep 24, 2020 8:33 am
by michel49
Thank you Mike, I'll give it a try.

Re: twin turbine RPM

Posted: Thu Sep 24, 2020 10:59 am
by MikeB
ReSt wrote:
Wed Sep 23, 2020 5:25 pm
Mike, could you, occasionally, push the latest modifications onto github ?

Reinhard
I've just pushed erskyTx, I'll push er9x later today.
I'll try to remember to push changes more frequently.

Mike

Re: twin turbine RPM

Posted: Thu Sep 24, 2020 3:58 pm
by ReSt
Thanks Mike

Reinhard

Re: twin turbine RPM

Posted: Sun Oct 04, 2020 11:23 am
by jhsa
MikeB wrote:
Wed Sep 23, 2020 2:43 pm

In passing, I see I've been working on er9x/erskyTx for over 9.5 years! At present, I'm having a bit of a break from "wall-to-wall" programming, just doing a few fixes and some things that interest me. I'll probably get back to doing more in a while!

Mike
Wow, Have I been using Er9x that long? :o :o :lol: :lol: :mrgreen:

Thanks for making your hobby much better and interesting Mike. Many (now) standard features in radios only exist due to your (and some others) innovative work. It is unbelievable what you did in 9 and a half years.. You totally improved the way model aircraft are programmed.
Thank you, and thank you.

I have also been doing other things at the moment, mainly for my work with music. and it involves electronics and programming, I have been learning both..
Before, I could light some LEDs with a microcontroller, but now I am a step further, i can also use buttons to switch the LEDs ON and OFF :mrgreen: Huge improvement :mrgreen:

João