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#2599791 - 10/06/08 08:09 AM imprecise il2 throttle input  
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kid_SA Offline
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I've completed the first draft of my controls. Imperfect, but they work well. This includes a stick, rudders, etc and a throttle. Using DIView, I can control the throttle (which is governed by a non-enclosed Hall sensor and interpreted by Leo's 12-bit board) to great precision, inside of decimal places within percentage points. Fully calibrated, this throttle has an (un-needed, I guess) accuracy of 3400 steps. And yet, il2 will sometimes skip percentage points. A mild annoyance, but still, I'd like precision that matches my hardware if possible. Not always the same points, but sometimes I take off and my throttle is unable to settle on 80%, for example (among other points). The game only allows 79% and 81%. There is throttle movement between those points, but this is not picked up by the game.

I realise that this isn't exactly a general sim-pit question and might be entirely software related, but I thought this would still be the best place for it. Can anyone help?

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#2599952 - 10/06/08 01:32 PM Re: imprecise il2 throttle input [Re: kid_SA]  
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Brandano Offline
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Caput Mundi (well, it used to ...
I am reasonably sure that IL2 is able to set an 80% throttle, and that it can be set by keyboard input as well. You might want to have a look into the control curves used by the software, though. The number of discrete steps available to the simulation might be an issue too. If internally the throttle is stored as a 2^7 number (a 7 digit binary value) it will have a range between 0 and 127. Allow for emergency power and you would still have enough resolution for all percentage values. If it's stored as a 6 bit number it will only have 65 steps, and will have to spread these through the 0-110% range of the throttle. I doubt they skimped on 2 bits, though, my guess is that the resolution of the throttle is a full 256 steps.

#2599979 - 10/06/08 02:20 PM Re: imprecise il2 throttle input [Re: Brandano]  
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kid_SA Offline
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il2 can definitely do 80%. The values that are inaccessible to me are not fixed. Sometimes I'll jump from 79 to 81, other times from 78 to 80, for example (I cruise at 80, hence my mentioning this value, but there are "missing" discreet steps all along the spectrum). That's what's got me puzzled. The game should do it, my throttle definitely can, my input curve is a completely linear set of values. il2-JoyControl, for example, works along a set of values from -1000 to 1000, and I can move from single digit to single digit if I'm very slow and careful. I can't figure it out.

edit: now that I'm looking, I can actually see the individual discreet steps for the stick in il2. It causes a bit of jerkiness that I'd thought was interference, but now, comparing the delta values (the amount of variation) from DIView to the displacement of the stick in il2, I think it's just slight movement of the stick in my hands (no centering yet) moving from one discreet step to the next with nothing in between.

Could my il2 be configured for low CPU or something, and have reduced the number of discreet steps as some kind of performance trick? Is there a way to increase them? What a waste for all good sticks.

Last edited by kid_SA; 10/06/08 02:40 PM.
#2600004 - 10/06/08 03:06 PM Re: imprecise il2 throttle input [Re: kid_SA]  
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Brandano Offline
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you shouldn't be looking at the throttle value while flying, hearing the engine ought to be enough! In any case, I think it might be more due to the joystick drivers or directinput than with IL2 itself. The performance gain they would get from using 6 bit math as opposed to 8 bit math is negligible.

#2600080 - 10/06/08 04:31 PM Re: imprecise il2 throttle input [Re: Brandano]  
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kid_SA Offline
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hehe. Yup, I should. It's on my to-do list to fly completely without any HUD info. I suppose I could complain about how I cannot get specific values for inches of mercury, but... :P

If it's joystick drivers or directinput then surely it would just be imprecise in all applications, wouldn't it? Mine is very precise in all applications except il2.

This is frustrating.

#2600447 - 10/07/08 07:03 AM Re: imprecise il2 throttle input [Re: kid_SA]  
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mmitch10 Offline
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For what it's worth, I get exactly the same thing using my BU086. One thing I've not tried yet (and I will tonight when I get back from work) is to map throttle back to the throttle lever on my Saitek stick, so see if that moves the throttle in smooth increments of 1%. At least that would show whether it's the hardware or IL2 giving the effect.

#2600829 - 10/09/08 06:09 AM Re: imprecise il2 throttle input [Re: mmitch10]  
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kid_SA Offline
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well, that would be interesting! Thanks, please let me know how that turns out.

EDIT: I've just done a test in LOMAC. I don't think there is a convenient HUD for the throttle (someone please tell me if there is) and the gauges are hard to judge in the 1% mark, but I can say that the jitter around the stick is absolutely 100% eliminated. It is silky smooth and appears much more precise, more so even then my X52, though my new stick still has low delta (from interference) values, which the X52 didn't seem to have. I certainly cannot see the stick move in steps, like I can in il2.

Programs that seem to work perfectly include DIView, Joycontrol and LOMAC. Only il2 seems imprecise, no others. Odd.

Last edited by kid_SA; 10/09/08 06:32 AM.
#2601329 - 10/09/08 07:33 PM Re: imprecise il2 throttle input [Re: kid_SA]  
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mmitch10 Offline
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Ok, well I'm not sure what to make of this.

Test 1...using my BU086 connected to a 10k slider pot for the throttle...the throttle doesn't quite go in increments of 1%. If you move the lever very carefully it will go, for example, 77, 78, 79, 81, 82, 83 etc, as kid_SA found.

Test 2...using the throttle lever on my Saitek Force Evo...exactly the same

Test 3...now this is the odd one. My control box has a couple of 10-turn potentiometers that I use for trim. These give very fine control, so I mapped one of those to the throttle, and exactly the same thing happened. I didn't really expect that, as the degree of control given by the 10-turn pot is much finer than the joystick throttle or the throttle that I made with my control box.

For what it's worth, I tried mapping the same controllers to propellor pitch, and it gave the same results. As kid_SA pointed out, it's not always the same. One time it may go 77, 78, 79, 81, 82, 83 etc, the next time it may go 77, 78, 80, 81, 82 etc

So the conclusion is that it is the way IL2 is interpreting the analogue inputs. Beyond that, I've no idea how to make sure it captures each percentage increment. Any ideas anyone?

Last edited by mmitch10; 10/09/08 07:42 PM.
#2601690 - 10/10/08 06:11 AM Re: imprecise il2 throttle input [Re: mmitch10]  
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kid_SA Offline
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well, partial victory then! All evidence corroborates one fact: our gear is just fine, more than precise enough, but il2 is not. More discreet steps would be nice though, I notice the increments in my stick and my 5-turn pots still, causing a certain jerkiness. In LOAMC, I think there is a *.ini file somewhere that actually has the number of discreet steps calculated. I wonder if there is something similar in il2.

Barring that, at least we know that our gear will be 100% fine for RoF and SoW (and BS).

Thanks for taking the time to test, Mitch, much appreciated.

I'll post in a few il2 forums at some point in the future. If we find anything, let's post it here, for posterity.


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