"Dead Space" on the sticks?!

er9x is the best known firmware. It has a superb range of features and is well supported by the community. Well worth trying out.
Post Reply
mambamax1
Posts: 30
Joined: Wed Aug 01, 2012 9:24 pm
Country: -

"Dead Space" on the sticks?!

Post by mambamax1 » Wed Aug 08, 2012 12:41 am

First off, I tried searching. I know how much forum veterans hate newbies asking redundant Q's. ;) So far though, this forum has actually be pretty nice and willing to help me, a er9x newb out. :D

Was out flying my quadcopter today, getting used to the new "feel" of the radio and noticed something strange. There is "dead space" on the sticks. I have to raise the throttle stick up 1/4 of the way to get a response, but after that, its fine. The same applies to the other channels. Except its on the other end. They max out before the stick bottoms out.

In the code of Multiwii (the "brain" of the quad's control board), all sticks need to be centered at 1500, and can't exceed 1000 on the low range, or 2000 on the high range. I had to adjust all 4 channels so that they did not exceed the 2000 mark (avg. endpoint adjustment for the high end was 89-91 out of a max of 100). Problem is the low end range for all channels needed to be set a little lower, but they were all maxed out at -100. I bet something in the negative 105-107 mark would do the trick.

Is there a way to shift the range as a whole to the lower side slightly? I bet this would solve my issue.


Suggestions? (If I didn't explain clearly, let me know....did my best!)
Thanks!

User avatar
Crucial
Posts: 581
Joined: Tue Dec 27, 2011 6:56 pm
Country: -
Location: SE WI, USA

Re: "Dead Space" on the sticks?!

Post by Crucial » Wed Aug 08, 2012 1:08 am

Have you performed a calibration on your sticks and pots? My multi wii setup needs the endpoints set to 98 and -98 on all sticks and it's 1000 - 2000 all around.

User avatar
gohsthb
Posts: 1412
Joined: Wed Dec 28, 2011 2:32 pm
Country: -
Location: Naperville, IL

Re: "Dead Space" on the sticks?!

Post by gohsthb » Wed Aug 08, 2012 1:55 am

You could turn on extended limits. Then you would be able to set the endpoints to +/- 125

-Gohst

mambamax1
Posts: 30
Joined: Wed Aug 01, 2012 9:24 pm
Country: -

Re:

Post by mambamax1 » Wed Aug 08, 2012 4:19 am

Crucial wrote:Have you performed a calibration on your sticks and pots? My multi wii setup needs the endpoints set to 98 and -98 on all sticks and it's 1000 - 2000 all around.

Yeah, I made sure to do that asap.
gohsthb wrote:You could turn on extended limits. Then you would be able to set the endpoints to +/- 125

-Gohst

Geeze, you are a wiz! I figured there was a way. I'm liking the ER9x more and more!

User avatar
MikeB
9x Developer
Posts: 14038
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset

Re: "Dead Space" on the sticks?!

Post by MikeB » Wed Aug 08, 2012 3:16 pm

I would say you still have a calibration problem or something else. When calibrated, and a mix output set for 100% stick, the output pulse should centre on 1500uS, and move 512uS either side with no dead space at either end. Using 98% pulls this into 1500 +/- 501.

Mike.
ersky9x/er9x developer
The difficult we do immediately,
The impossible takes a little longer!


mambamax1
Posts: 30
Joined: Wed Aug 01, 2012 9:24 pm
Country: -

Re: "Dead Space" on the sticks?!

Post by mambamax1 » Thu Aug 09, 2012 9:41 pm

MikeB wrote:I would say you still have a calibration problem or something else. When calibrated, and a mix output set for 100% stick, the output pulse should centre on 1500uS, and move 512uS either side with no dead space at either end. Using 98% pulls this into 1500 +/- 501.

Mike.

I've calibrated the radio already. What else could I do to get it calibrated correctly?

User avatar
MikeB
9x Developer
Posts: 14038
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset

Re: "Dead Space" on the sticks?!

Post by MikeB » Thu Aug 09, 2012 11:02 pm

OK, lets investigate the calibration. Go to the ANA screen (5/6 of the radio setup so LONG LEFT from the main screen, then RIGHT 4 times).
This screen shows the actual analog value of the sticks (in hexadecimal), together with the calibrated value (-100 to +100).
Move the throttle stick and check which numbers change, if throttle is the left stick, it should be A2.
Put the throttle stick in the centre and look at the two numbers, I'd expect 400 (3C0 to 440) and 0 (-5 to +5).
Now slowly move the throttle stick towards low throttle, the hex value should get smaller and the other value move towards -100. If the second number gets to -100 significantly before the hex value gets to 000 (or close to 000, say 040) i.e. before the throttle stick hits the mecahnical limit, then the throttle stick is not calibrated properly.

Mike.
ersky9x/er9x developer
The difficult we do immediately,
The impossible takes a little longer!

mambamax1
Posts: 30
Joined: Wed Aug 01, 2012 9:24 pm
Country: -

Re: "Dead Space" on the sticks?!

Post by mambamax1 » Thu Aug 09, 2012 11:34 pm

Ok, ran that little test. At minimum throttle, my hex value is 0056 while throttle is at -100. I've calibrated my sticks a few times but it never made a difference?

Edit: Also looked to see when the throttle actually started to respond. When throttle is at -60 is when I actually notice the quad-copter throttling up. :?:

User avatar
Kilrah
Posts: 8917
Joined: Sat Feb 18, 2012 6:56 pm
Country: United Arab Emirates

Re: "Dead Space" on the sticks?!

Post by Kilrah » Fri Aug 10, 2012 6:48 am

mambamax1 wrote:Edit: Also looked to see when the throttle actually started to respond. When throttle is at -60 is when I actually notice the quad-copter throttling up. :?:
Sounds like a configuration issue on your quadcopter then. Did you calibrate your ESC's?

mambamax1
Posts: 30
Joined: Wed Aug 01, 2012 9:24 pm
Country: -

Re: "Dead Space" on the sticks?!

Post by mambamax1 » Fri Aug 10, 2012 1:22 pm

Actually, I hadn't thought of that until last night. Here's a post I put on RCG:


Ok just switched from a CT6B radio to a Turnigy 9x flashed with ER9x firmware. All has been good until tonight. Yesterday I realized that I need to move my throttle stick up 40% of the way before I get a throttle response from the quad. Earlier, I realized that I hadn't calibrated my escs to the 9x and figured that this would most likely solve the throttle issue. "No biggie" I thought. Well 3 hours later, I finally got myself back to square one. :mad: Basically, my 9x is having issues. When I calibrated my escs to the 9x, my quad, using a multiwii board, I could not get it to idle when armed. Also, 2 of the motors (front left, rear right) would NOT spin (the escs for those 2 couldn't arm)

All trims centered at 1500
All values above 1000 and below 2000

No matter what I tried I could not get the 9x to cooperate with the escs calibrated to it. So, I just re-calibrated all my esc's back to the CT6B (old radio) and just bound the 9x back to the quad.....maintaining the escs' calibration to the CT6B. So now, everything "works" but I still have no throttle response for the first 40% of throttle movement.


I've been into quads for 4 or so months now. I'm not a pro, but not a newbie my any means. I've racked my brain over and over for a solution but I'm at a loss. :?:

User avatar
MikeB
9x Developer
Posts: 14038
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset

Re: "Dead Space" on the sticks?!

Post by MikeB » Fri Aug 10, 2012 1:55 pm

Do you have a method of measuring the pulse widths from the CT6B radio? If so, then 'all' you need to do is set the 9x up to generate the same pulse widths using the mixes or limits.

While servo pulses are 1500 at centre, and 100/200 at the ends, many commercial radios don't use this full range for the stick movement, often they only use 70-80% of this, and allow the rest for use by trims. So you might find the sticks move from 1150 through 1500 to 1850 with the trim at centre, but with 50uS of trim on they move from 1100 through 1450 to 1800. This way, you don't exceed the 1000 to 2000 limits for the servo.
Er9x (and other custom firmware) gives you the full 1000 to 2000 on the stick, when the mixes and limits are set to -100 and +100. If you apply trim, you will lose some throw on the side the trim is on, but you have so much throw already this doesn't usually matter.

With er9x, there are many different ways of adjusting the amount of servo movement for a given stick movement. The 4 main ways are:
Mix weight - affects both stick and trim
Limit - affects both stick and trim
Dual rate - only affects stick
Curves - only affects stick.

If you have eepe, you can 'play' with each of these easily and simulate the effect they have on the output, then decide which is best for you requirement.

Mike.
ersky9x/er9x developer
The difficult we do immediately,
The impossible takes a little longer!

User avatar
Kilrah
Posts: 8917
Joined: Sat Feb 18, 2012 6:56 pm
Country: United Arab Emirates

Re: "Dead Space" on the sticks?!

Post by Kilrah » Fri Aug 10, 2012 3:06 pm

I seem to have understood your multiwii GUI shows you the pulse lenghts, right?
If yes, you can use that to do what Mike suggested. Just write down the values from the old radio, and set the limits on the 9x to achieve the same.

PeterV
Posts: 75
Joined: Sun Feb 26, 2012 9:33 pm
Country: -

Re: "Dead Space" on the sticks?!

Post by PeterV » Tue Aug 14, 2012 1:10 pm

While possible 'dead zone' is being mentioned....
Is there a way to HAVE some dead zone at mid stick?

User avatar
Kilrah
Posts: 8917
Joined: Sat Feb 18, 2012 6:56 pm
Country: United Arab Emirates

Re: "Dead Space" on the sticks?!

Post by Kilrah » Tue Aug 14, 2012 2:37 pm

It's easy to "mute" the stick if its value is smaller than some number.

For example:
SW1: |v|>ofs AIL 5
Your aileron channel: 100% AIL Switch(SW1)

However this means that once your aileron channel becomes active it "jumps" directly to from 0% to 5%.

Must be possible to have it start cleanly from 0 (and still have it reach 100%), but OTOH I don't see how to do it easily on er9x, would take some more thinking.
On open9x a 5-point curve with custom X positions would work wonders for it.

User avatar
MikeB
9x Developer
Posts: 14038
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset

Re: "Dead Space" on the sticks?!

Post by MikeB » Tue Aug 14, 2012 4:12 pm

There may be other ways, but this works on er9x:
CH1: +100% AIL Offset 5%
CH1: R 100% AIL Switch(SW1) Offset -5%
CH1: R 0% AIL Switch(SW2)

CS1: v>ofs AIL 0
CS2: |V|<ofs AIL 5

This gives a deadband 5% either side of centre of the stick, change the 5 in the three places (two mixes, 1 switch) to change this.
NB the second two mixes are REPLACE not ADD.

Mike.
ersky9x/er9x developer
The difficult we do immediately,
The impossible takes a little longer!

User avatar
Rob Thomson
Site Admin
Posts: 4531
Joined: Tue Dec 27, 2011 11:34 am
Country: United Kingdom
Location: Albury, Guildford
Contact:

Re: "Dead Space" on the sticks?!

Post by Rob Thomson » Thu Aug 16, 2012 4:54 am

I am pretty sure a similar solution was posts some time back by someone wanting to have a dead band to remove 'shakes' caused by there hand having a tremor.

At the time I thought it would make a great option for a simple 'anti tremor' on the system config page.


Sent from my iPhone using Tapatalk
Slope Soaring, FPV, and pretty much anything 'high tech'
...........if you think it should be in the wiki.. ask me for wiki access, then go add it!

PeterV
Posts: 75
Joined: Sun Feb 26, 2012 9:33 pm
Country: -

Re: "Dead Space" on the sticks?!

Post by PeterV » Mon Aug 20, 2012 10:36 am

Thanks for that Mike. What sort of memory use would that take up?
I guess you would need to do that for four channels, and the two CS's..... for every model.

With Custom Switches... they are model specific? I wouldn't think people need more than two or so for a model, so maybe all CS's should be global?
To save needing to reproduce common ones.
Though I haven't actually tested to see if they are global already! They are not, from what I recall seeing.

And having a DeadZone option built in.... that would be good, if it did not 'waste' too much memory to achieve it.

User avatar
MikeB
9x Developer
Posts: 14038
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset

Re: "Dead Space" on the sticks?!

Post by MikeB » Mon Aug 20, 2012 11:10 am

What is the purpose in having this dead-zone at the centre position? How 'dead' does it need to be?
If, for example, you set up 100% exponential on a channel, then (according to eepe) the first 10% of stick movement only gives about 0.1% of output movement, although you will get the exponential after that.

Mike.

Edit: Found the original (posted by Scott Page on RCGroups), much easier
CH02: +100% ELE offset 10% switch(x<0)
CH02: +100% ELE offset -10% switch(x>0)

This takes out 10% either side of the centre, although it also reduces the throw to 90%, use a weight of 111% to get it back.
ersky9x/er9x developer
The difficult we do immediately,
The impossible takes a little longer!

User avatar
unisev
Posts: 5
Joined: Wed Jul 18, 2012 8:48 am
Country: -

Re: "Dead Space" on the sticks?!

Post by unisev » Thu Aug 23, 2012 4:53 pm

PeterV wrote:And having a DeadZone option built in.... that would be good, if it did not 'waste' too much memory to achieve it.
My gimball "age" and the neutral position is moving a little bit, so I 100% agree with this, is it possible to "ask for it" ?
er9x user

handsomejackuk
Posts: 23
Joined: Mon Oct 20, 2014 11:00 pm
Country: -

Re: "Dead Space" on the sticks?!

Post by handsomejackuk » Sun Oct 26, 2014 10:25 pm

bump this post for reference

lanerover
Posts: 25
Joined: Mon Jul 22, 2013 4:35 am
Country: -

Re: "Dead Space" on the sticks?!

Post by lanerover » Mon Apr 17, 2017 11:46 am

hi Guys I doubt this thread is still active but if it still is can anyone point me to the Scott Page item detailed above, i just can't make this work on my quad which is darting everywhere whenever i apply throttle. Thanks in anticipation, Kevin

Daedalus66
Posts: 1620
Joined: Tue Dec 27, 2011 8:22 pm
Country: -
Location: Ottawa

"Dead Space" on the sticks?!

Post by Daedalus66 » Mon Apr 17, 2017 12:54 pm

See item #18 above.

If you are using ERSky9x, you can easily add deadband in the Hardware menu (hold left horizontal trim to the left while turning on to gain access).

Are you sure expo and dual rate won't do what you need.

lanerover
Posts: 25
Joined: Mon Jul 22, 2013 4:35 am
Country: -

Re: "Dead Space" on the sticks?!

Post by lanerover » Mon Apr 17, 2017 1:33 pm

actually it an original Taranis x9d not the plus updated to opentx2.017. obviously ive got something badly wrong having turned up expo on the rudder to 100% and nothing happoens

Daedalus66
Posts: 1620
Joined: Tue Dec 27, 2011 8:22 pm
Country: -
Location: Ottawa

Re: "Dead Space" on the sticks?!

Post by Daedalus66 » Mon Apr 17, 2017 1:57 pm

"Nothing happens". Could you be a little more explicit, please. I assume you're looking at the Graphic outputs main screen and that you are saying the rudder channel shows no action whatsoever. Do you have a suitable mix on the channel? Never mind expo for now.

lanerover
Posts: 25
Joined: Mon Jul 22, 2013 4:35 am
Country: -

Re: "Dead Space" on the sticks?!

Post by lanerover » Mon Apr 17, 2017 10:24 pm

My apologies for not being specific, the stick control of the rudder remains exactly the same even with 100% expo or the Scott Page mixes detailed, the slightest deviation from centre when applying throttle causes the quad to move in whichever way the stick has moved slightly. Having suffered 3 strokes i experience a great amount of difficulty keeping the stick dead centre when applying throttle. Kevin

Daedalus66
Posts: 1620
Joined: Tue Dec 27, 2011 8:22 pm
Country: -
Location: Ottawa

"Dead Space" on the sticks?!

Post by Daedalus66 » Mon Apr 17, 2017 10:45 pm

Forget everything but what the transmitter is doing. No expo, no receiver, no servos, no quad, etc. Create a new model with just the four stick channels. What does the graphic outputs screen show (the one with the bars showing servo positions) when you move each of the sticks slowly through their full movement?

lanerover
Posts: 25
Joined: Mon Jul 22, 2013 4:35 am
Country: -

Re: "Dead Space" on the sticks?!

Post by lanerover » Fri Apr 21, 2017 2:37 pm

Sorry guys been ill for last few days everything appears normal with the output screen the only thing it reveals is that i probably need a dead area of around 15% either side o f centre.

User avatar
RCHH
Posts: 411
Joined: Sun Jun 24, 2012 2:48 pm
Country: -
Location: Plymouth

Re: "Dead Space" on the sticks?!

Post by RCHH » Sat Apr 22, 2017 6:50 pm

lanerover wrote:
Fri Apr 21, 2017 2:37 pm
Sorry guys been ill for last few days everything appears normal with the output screen the only thing it reveals is that i probably need a dead area of around 15% either side o f centre.
Could you not setup a curve to do that?

http://openrcforums.com/wiki/index.php/ ... ves_7.2F12
The simpleton asked "Hows about ErSky9X for Horus???". And the Genius from Dorset replied "Why not indeed? I shall get right onto it!" And then there was light on Horus! And it was good!

Post Reply

Return to “er9x”

Who is online

Users browsing this forum: Bing [Bot] and 1 guest