Using AUX Knob on Devo-10 as (Yaw) Channel Scalar?

Folks,

I have a photography-based requirement to be able to adjust my quadcopter maximum Yaw rate, based on the input from one of the two Devo-10 "AUX input" potentiometers. This pot input needs to act as a "Scalar" to the Yaw output channel, limiting the maximum value sent to the Yaw channel. This scalar does NOT need to be "fine-grained" with every tiny bit of potentiometer rotation changing the output scalar value, but instead I would be happy with maybe 8 or 10 "steps" throughout the entire potentiometer rotation.

In otherwords, I do NOT want the AUX pot to directly affect the Yaw, but rather to "Limit" how fast the aircraft "spins" when the Yaw stick input is mashed to maximum. Hope that makes sense!

Does anyone here know how this could be implemented in a Deviation model .ini file?

Thank you!

No, it doesn't make sense, because "how fast the aircraft spins" is the yaw rate. So to affect that spin rate, the AUX knob has to affect the yaw pretty directly.

That said, I can see two ways to do things. One may be what you want. You'll need to use the advanced GUI (and should be if you're using a quad anyway).

Add an extra mixer to the end of your rudder (which controls yaw) channel mix. Set the input to either AUX4 (left) knob or AUX5 (right knob). Set the curve to 1-1. Set scale to 50, and offset to 50. You should now have a curve that goes from 0% to 100% as the knob goes from one side to the other.

Now for the choice. Set the Mux type to either "Mul" or "Min". If you set it to Mul, the AUX knob will act like a "rate" dial. Both cap the maximum rate of the rudder - and hence the yaw rate - at the value of the AUX knob (assuming you weren't outputting values >100% before, anyway). The Mul option scales the entire range, like a rate selection. The Min option just ignores motion beyond the current knob setting, but lower settings act like they did before.

Final tweaks: Change the scale & option values so that the bottom isn't 0, which effectively disabled the rudder control. Edit the model#.ini file on your computer (don't use notepad; use notepad++ or a Unix or Linux system) and find the "[safety]" section, which probably has a line like "Auto=min" in it. Add "AUX5=max" (or AUX4 if you used that) line to get a warning if the knob isn't at 100% when you turn on the transmitter/load that model. This can't be done via the transmitter interface, but the warning could prevent you from trying to fly with a limited yaw.

Two more options: You can make the dial work in the other direction by negating the scale and offset values. And you can set a switch to that last mix so you can turn this off if you want.

Exercise for the reader: Use a virtual mix to set scale & offset instead of using the AUX knob directly, then add the value of that mix to the main page display so you can see the "rate" setting.

mwm,
Thank you for the great reply!

I guess what I was trying to say with the "affects the yaw rate" bit is this:

I do not want "twisting" the AUX input knob to directly CAUSE the aircraft Yaw movement to change. I want the AUX input to SCALE (throughout it's range) the actual Yaw stick input (by ratio multiplication) so that it limits the maximum Yaw rate, as well as keeping the Yaw "range" smooth and linear (I don't want to just "chop" off the top end).

Example: At "full" AUX pot setting, the Yaw stick inputs are multiplied by 100% (essentially "passed through") to the Yaw output channel. At "half" AUX pot setting, the Yaw stick inputs are multiplied by 50% (X 0.5), making the maximum output to the Yaw channel half of the "normal" maximum value. A Yaw stick input of half would end up being sent to the outpot channel as 1/4 of the "normal" maximum value, and so on.

Once again, I do NOT necessarily need "fine grain" granularity, 10 or so "steps" would be fine... though "fine grain" would be nice if it were achievable!

Hope this clarifies my intent.

P.S. It sounds like the "mul" is the command I'm after. I'll give it a try. Do I need to assign the "adjusted" (with offset) AUX channel to a virtual channel first? I'm very new to all of this.

Thank you!

What flight controller? Cleanflight allows exactly what you're asking all handled internally. Devo just sends normal channel ranges with no mixing.

Adjustments tab, set your ranges (don't forget to set the off ranges, 100% of the range must be used, set what you want to be on and set the rest to "no change") then choose adjust yaw RATE. You can then enable and disable this adjustment with a switch (or just have it on all the time if you want)

Cereal_Killer wrote: What flight controller? Cleanflight allows exactly what you're asking all handled internally. Devo just sends normal channel ranges with no mixing.

I'm using Deviation 5.0.0 on a Devo-10, running SymaX protocol to control Syma X8C aircraft. The flight controller would be whatever the Syma X8C uses, probably something proprietary and closed source. I just want to modify the Yaw stick output value (based on the AUX pot setting) before it is sent to the aircraft through the output channel.

P.S. I'm trying to do this by directly editing the model .INI file, instead of using the controller's UI.

P.P.S. I know that the Syma X8C is a "toy" quad, and that I really SHOULD "upgrade" to a "real" brushless design with open source flight controller. However... I'm getting GREAT results with my "toys", pushing them into camera work territory reserved for $1,000+ camera drones! Plus, I can totally DESTROY several of them plus the cameras and still be ahead financially over what a Phantom or something similar would cost. I find this particular challenge to be a whole lot of fun!

Can anyone here tell me how to use the mul command in an .INI model definition file? Do I have to send the modified AUX channel potentiometer data (with offset, to make its range 0-100) to a virtual channel before using the mul command in a mixer? What would the resulting code look like if my Yaw (Rudder) channel is ch4, and I'm using AUX4 as the Devo-10 pot input?

I really am new to all this, and I'm having a hard time finding an .INI model file example anywhere.

Thank you!

mwm has a nice guide on programming with deviation on his blog here >> rc.mired.org/p/blog-page.html there is also a link at the bottom of the page that goes into more detail. those pages should get you well on your way bud

HappyHarry wrote: mwm has a nice guide on programming with deviation on his blog here >> rc.mired.org/p/blog-page.html there is also a link at the bottom of the page that goes into more detail. those pages should get you well on your way bud

Yes, I've gone over those in great detail, and other tutorial PDFs as well. None of them are answering my core question:

When making a model .INI file, how do you take the AUX4 pot input, scale it 0-100, then multiply the Yaw (Rudder) stick input by the result before outputting to CH4? What does the CODE look like, not the theory? I'm too new to this to work it out on my own, without HUGE trial and error!

I think I might need to use a virtual channel, but I'm not sure. Also, I've looked through literally DOZENS of model .INI files trying to find an example of the mul command being used, with no luck.

I'm so frustrated! I'm almost to the point of just trying anything and everything I can think of by trial and error... but I'm sure SOMEBODY here knows how to do this. PLEASE HELP!

I don't know of anyone who has done this, or if it's even possible to do what you want bud, I've never needed anything like this and with dual/triple rates and 3 or more possible flight modes that can all adjust your yaw channel rate I don't think many will have tried to either

Fire up the emulator. Use the Tx interface to create the mixer you want, with the mul mix. Now load a different model to save this model. Now open the model file the emulator just saved. It'll be in filesystem/devo10/models in the same folder as the emulator.