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Limit throttle with a pot

Posted: Sat Jan 14, 2017 5:14 am
by interestingfellow
I want to be able to switch Thr to use one of my pots to limit the maximum throttle available to the throttle stick. How would I do that? Currently I have

CH1 Thr 100
:= MAX -100 ELE (this is my Thr kill)

I want to add a switch to make the Thr be limited by a pot. What would that line look like?

I tried setting a switch to use a pot to do so, but multiply or replace doesn't get me the behavior I'm looking for. I want 0 on the pot to be 0 max throttle available even when Thr is at 100%, %60 on the pot to be %60 max throttle when Thr is at 100%, etc.

I basically want to be able to flip a switch and limit my max speed but still use the entire Thr throw.

Sorry to be so unclear and repetative, I don't know how to more clearly communicate my goal. There are other applications that this will be usefull to me for.

Thanks!

Re: Limit throttle with a pot

Posted: Sat Jan 14, 2017 9:52 am
by MikeB
A check on your requirement. Sticks and pots go from -100% to +100%, when you say "0 on the pot", do you mean 0 as i the centre position or do you mean fully one way?

Mike.

Re: Limit throttle with a pot

Posted: Sat Jan 14, 2017 10:11 am
by MikeB
Try:
CH03: -100% Thr Offset(-100%)
* +50% P1 Offset(50%)
+100% Thr

I suggest you use a Safety switch for your throttle kill.

Mike.

Re: Limit throttle with a pot

Posted: Sat Jan 14, 2017 1:22 pm
by interestingfellow
"Sticks and pots go from -100% to +100%"

I think that's where I was getting screwed up. I was thinking 0 to 100, not -100 to100. I'll report back after I check.

Thanks!

Re: Limit throttle with a pot

Posted: Sat Jan 14, 2017 1:25 pm
by interestingfellow
...what would a safety switch look like? i thought that's what my ELE switch was.

Re: Limit throttle with a pot

Posted: Sat Jan 14, 2017 2:45 pm
by MikeB
It is in the "Safety switch" menu!
Try:
X ELE -100 Thr
The 'X' is a "sticky" safety switch. This means when you enable the throttle, you still need to put the throttle stick to -100% before the throttle output will respond.

Mike.

Re: Limit throttle with a pot

Posted: Sat Jan 14, 2017 3:15 pm
by jhsa
Mike, I see one of his mixes uses the source "MAX", that means he is using openTX, so he might not have the sticky throttle safety switch, or it is done in a different way.

João

Re: Limit throttle with a pot

Posted: Sat Jan 14, 2017 5:34 pm
by interestingfellow
Sorry! Yes, opentx.

Re: Limit throttle with a pot

Posted: Sat Jan 14, 2017 5:59 pm
by MikeB
In that case, I think it is a Function of type Override, but it won't be sticky.

Mike.

Re: Limit throttle with a pot

Posted: Sun Jan 15, 2017 4:00 am
by interestingfellow
Step away from my original question for one moment and correct me if I'm wrong, please:

When I use P1 as my input it is giving -100 to +100 over the whole throw of the knob.
When I involve an "offset" value, that value is added to the value low value (-100) of the input (P1) for the output, but still over the whole throw of the knob.

IE>
P1 + Offset of +50 will output -50 to +100
P1 + Offset of 100 will output 0 to +100

But I will still have full throw on the P1 knob.
Is that correct?

Re: Limit throttle with a pot

Posted: Sun Jan 15, 2017 9:56 am
by MikeB
I think openTx is the same as ersky9x and the answer is NO, you will get an output of 0 to 200%. This, if used alone on a channel, will be limited to output 0-100% over the first half of the pot movement, the second half will do nothing.
Use:
+50% P1 Offset(50%)
to get 0-100% output over the full pot movement.

Mike.

Re: Limit throttle with a pot

Posted: Sun Jan 15, 2017 1:52 pm
by interestingfellow
so the offset value is 0% to 100% with a "-" value being inverted....OK! Let me simmer with that for a while.

Thanks!

Re: Limit throttle with a pot

Posted: Sun Jan 15, 2017 4:22 pm
by jhsa
if you want to understand how the offset works, download the Er9x manual and go to page 33. There is a good explanation.
viewtopic.php?f=5&t=6473
OpenTx works the same in this case..

João

Re: Limit throttle with a pot

Posted: Sun Jan 15, 2017 10:16 pm
by interestingfellow
LOL!
I specifically remember that box about offsets from when I read that manuak.

I also remeber having trouble "getting" it and thinking "screw it, I won't need it anyway"


Karma comin back around, reaping what you sew, etc...

Re: Limit throttle with a pot

Posted: Wed Jan 25, 2017 2:21 am
by interestingfellow
I don't get it.

What I do "get" is using a switch with different curves set up.
Bam. Problem solved....alternately.