New Forum Survey: Homebrew Cockpits (see below)

[JBaymore]

Hi all......

This post should really be another topic if this were a forum section:

Help with second joystick installation question

Can I install a second USB joystick unit and then map it's buttons to a set of different functions in the sim from the ones handled by the primary joystick?

Would this have to be the same brand of joystick to make it work?  Or would it be best if it were a DIFFERENT brand?

Am I right in assuming (bad idea  ;) ) that a joystick with a throttle, pitch, bank, and twist (yaw) will have four analog position inputs?

I am hoping this is possible..... so that I can use those four analog inputs for ANOTHER use than is typical  ;).

best,

................john

[Professor Brensec]

Obviously, anything that generates interest, especailly in SimV, is going to be discussed either in general terms or specifically, by those who are interested.

So, accordingly, the fact that the discussion has digressed from a simple 'yes/no poll' to actual discussion of the ways and means etc of the idea, is testimony to the interest is has generated.

I don't see why there is any more need to 'wonder' if the subject would be worth at least, trying as a temporary 'section'.
Of course this is up to the 'powers that be'.  ;D

[Smoke2much]

Yes John, in answer to your question you can add a second USB device and map differant functions to the buttons.  At one point I had a joy pad and joystick attached.  Problem was I couldn't remember what the various buttons were supposed to do and I had to let go of the joystick (primary flight control) to grab the joy pad.

Will

[fido]

Attention Powers That Be
    John and the Professor are sooo right.  This project needs it's own forun to grow and prosper.  If you can not find it, you can not contribute to it.  Heck, if it does not receive enough traffic, close it.
                                        Fido

[JBaymore]

Will,

Thanks for that information on connecting the second USB joystick.  I figured that might likely be possible..... since you can set up throttles, and yokes, and pedals all together.  But I wondered if there were some "caveats" about doing so.

What I am thinking with this question is this..........

Since I am modeling a generic "heavy" cockpit..... I will need a four engine throttle quadrant.  The switches (pushbuttons / toggles) for various functions such as fuel pumps and cuttoffs and such are easy and kinda' self explanatory.  But the REAL issue is the analog input of each throttle position.

If I can canibalize a joystick with four analog potentiometers, then a mechanical structure creating a fake throttle quadrant could be constructed and then I could connect those four pots (or four other ones of the same values) to the four levers that are the "throttles".

I can already sort of envision the general construction of such a unit.  Not too hard...... some wood for the boxy frame with rounded tops on the sides, some plastic for various parts like knobs, a sheet off plastic or metal for the slotted top cover, a little rubber sheet for the "gaskets" in the lever slots, some metal straps for the throttle handles and the axis shaft around which they pivot, and a bit of epoxy, screws, and filddlin'.

And the various switch functions that the joystick has can then also be assigned either to the "engine" switch type functions..... or reserved for OTHER controls in the cockpit.  This may be the way that I have to simulate the thrust reversers........ rather than the typical levers.  Maybe a little button on each throttle lever.....kinda' like the "overdrive" buttons on many automatic car transmission shifters (  ;) ).  Not totally realistic.... but close.


Yeah...... the "remembering what is what" on generic unlabeled buttons is an issue.  But with the simulated cockpit setup....... you'll likely label each switch, the switches will stay in one place ( ), and eventually you will "know" your own cockpit layout much like you get to know the controls in your car after using it for a while.

best,

..............john

[JBaymore]

Fido + Professor,

Thanks for the support on the fourm idea.

best,

.............john

[Smoke2much]

Maybe that cannibalisation will work for trim levers/wheels as well.  I think most cockpit gubbins could be made very cheaply indeed as the realism is inherant in the action taken to effect a change in the simulator.  If you remember the days before the throttle lever on the joystick you will know what I mean.  You used to have to hit the + key to increase thrust.  Suddenly you have a joystick with a throttle lever and the whole thing is more realistic.  Simply having a thottle quadrant will make the realism greater, even if the four levers are connected to just one control that controlls the four engines simultaneously.

Incidentally with the moving cockpit idea that I am working on I'd like to add some more thoughts.  I went on one of those fairground type flight sims today where you are enclosed in a capsule and the whole thing moves.  I got slightly air sick LMAO, and the thing never banked more than 20 degrees.  It is a question of sensory deprivation linked to the illusion of movement greater than what is actually happening.

Will

[JBaymore]

If this thread were a separate forum section I'd probably use this message header:

Preliminary news on 4 engine throttle interface

With the interfacing of a 4 engine throttle control quadrant on my mind....and the thought from others that a second USB joystick could be installed under Win XP in FS2004..... I headed off to Walmart today to see what they had in a cheap 4 axis joystick.  Was expecting to be in the $50 range , plus or minus.  Quite a bit of money...... but what I thought was going to be necessary.

Then Will's comment about his using a joypad popped into my brain as I was looking at the offering there.

They had a cheap ($17) AxisPad FX usb dual joystick gamepad.  It had side by side small analog joysticks..... and a usb interface.  At that price I thought "What the heck" and I bought it.  Figured that if I was just looking for the circuit interface and the software drivers...... didn't need the rest of the heavy duty "joystick" parts that I'd have to pay for that I was not going to really use.  I'd be adding external switches and potentiometers anyway.

Brought it home and hooked it up.  Snap of an install in XP.  

Went into the FS2004 sim.  Now in the "Settings" part there are both the Logitech FF joystick and the Axis gamepad FX showing up there.  So far so good.  I went to "Assignments" and then selected the gamepad in the dropdown list.  Then I mapped one of the joysticks on the gamepad to engine one throttle.  Mapped the other one to engine four throttle.

Then went into "create a flight" and went to the default flight.  Poped up the virtual throttle quadrant.  I EXPECTED the main throttle on the Logitech stick not to work anymore.  But lo and behold..... when I ran it up..... all four engines spooled up.  Great.  At least it didn't screw things up  ;).

Holding my breath.... I pushed one of the gamepad joysticks forward...... then there on the screen ONLY engine one started spooling up.

So BINGO!!!!!!!!!!!!!  This looks like it will form the basis for a multi engine throttle quadrant interface.  Still a LOT to do.  I have no schematics..... and the inexpensive device is made in China so I probably can't get them.  So I still have to rip the thing apart and see if I can reattach four linear potentiometers to the thing and still get it to work.

The unit ALSO has 8 momentary buttions available and an 8 way hat switch.  All of which can be remapped for function in the sim.  So this would give you 16 more switches you can control stuff with.

And it has two vibreation feedback things that I have no idea how to interface  ;D.

This is a real WOW in moving this project forward inexpensively, I think.

I'll keep you posted.

best,

....................john

[Smoke2much]

John, I did the same and mapped the throttle to joypad mini joysticks a few months ago, the problem with the set up is that the central setting of the mini stick equates to 50% forward.  It is very difficult trying to land or taxi with your engines running at 50% thrust - trust me.

Will

[JBaymore]

Will,

Ah...... yes.... you are correct........ but I will now unsolder the two mini joystick potentiometers from the printed circuit board and replace them with four remotely mounted linear slide potentiometers that will themselves be actuated by four lever arms (making the throttle quadrant).  Each of those pots will then be a single engine throttle.

After all ....... this whole cockpit construction thing is about "tinkering".      ;D

On the joystick....... let's say that one axis of the pot is forward and back.  If it is a 100k ohm pot....... the center position is at 50k ohms.  So the signal sets the coordinate "position" of that stick to "center" in the sim when the resistance value is at 50k ohms.  When you move the stick full back..... the pot changes resistance heading toward 0 ohms.  So the "position" moves to the bottom.  So when you add a new pot ......... the zero ohm position relates to "full down".... and therefore idle throttle.  And the full "up" position now relates to 100k ohms and full throttle.

I may find that I have to add what are called "trim pots" along with the main linear control ones..... to fine tune the "range" of the throttle.  Those will be a "one time set" type of thing.  But that is a minor and simple addition.

The first trick here is to carefully unsolder the pots.... and then figure out which traces on the circuit board are the ones for each control axis.  Then I just take the pot and connect it to a multimeter and run it from full down to full up and see what resistance it is.  Once I know that..... I can get the linear slider pots to replace them with.

I will also add a "terminal strip" to all the switch contact points so that adding wiring for external switches will be far easier than trying to solder directly onto the circuit board.  Not sure if I'll use ribbon cable or not.

I will document all this construction as best I can and post all the work here on SimV.  I may also add something to my (non-flightsim) website.  I have been taking digital shots of the "destruction"  ;) of the gamepad.  Hopefully Pete will decide that a separate Forum dedicated to this kind of stuff is appropriate and there will be a "files" section created to put this kind of stuff into in something like PDF format.

The next thing I want to know here is if I get ANOTHER "cheapo" Axispad FX and install it in Win XP...... if it will get recognized as a third controller........ or because it is the same unit...... if it will get "confused" with the existing one.... and will then be difficult to "map" buttons and axis assignments in the sim.

Then there is stacking a CH products usb yoke on top of all those  ;).  Gotta get a (powered) usb port box too to support all of these usb addons.  


best,

.................john

[Vchat20]

what about the reverse throttle used on the Jets? how will that be added to your design JBaymore? or would it be a simple adjustment of the potentiometers?

[Smoke2much]

John,

I shouldn't worry too much about two of the same type of joystick plugged in at the same time.  My "Rudder Pedals" are the same type of joystick as my primary control and I get no issues.  I do need to get myself a book on electronics so that I can understand you.

Reverse thrust may be a little tricky as it is (on my set up!) unavailable as part of the throttle slider.  If anyone knows how to get it to work through the joystick I'll be in their debt.

Will

[JBaymore]

Will,

Thanks for that thought.  I always figured that the pedals would have some identifier of some sort that would allow Windows to ID them for their separate installation.  So that they may be the same brand.... but Win sees them "different".  But maybe not.  I am sure that shortly another Axispad FX will find it's way to my computer desk  ;).

As to the "electronics" business...........  oops..... sorry.  maybe this following will help a tiny bit:

"Ohms" is a unit measure of the resistance to the flow of electrons in an electrical circuit.  The term "K ohms" is one thousand ohms.  Something that impedes the flow of electrons in a circuit is called a "resistor".  A "potentiometer" (or "pot" for short) is a variable resistor.

A joystick uses two separate variable resistors (pots) to create a pair of resistance values that correlate to the position of the stick in the x and y axis.  So in computer terms you tend to think in terms of X and Y coordinates on the screen or in 3-d space.  But the joystick's initial input is actually analog in most cases....... it deals with voltages/current flow/resistance.  Then a circuit in the joystick converts those analog values into a digital representation that the computer can "see" and read.  

In many ways..... for the throttle type stuff..... we don't care HOW that analog signal gets converted.... just that it DOES.  THAT is the main reason for the gamepad in the first place.... it carries the "analog to digital" converter hardware and software.  That's basically what you are buying.

The throttle control on a joystick is just a slide potentiometer (resistor) of one sort or another.  Ditto the trim wheel if you have one.

Once you know the correct value of the potentiometer that a joystick uses.... which will be measured by the maximum resistance it will exhibit in "ohms"when fully to the end of its rotation or linear travel....... the circuit it is hooked to doesn't care if it is the original pot or another one of the same value located somewhere else.

So you could take a rotary potentiometer that has the same values as the original and hook it up so that when in the center position (just like the joystick was) it is mapped to "zero trim". Use wires to mount it sdeways with the knob protruding thru a slot in the main panel face next to the yoke.  Now it looks kinda' like a trim wheel too.  Turn the knob (wheel) attached to the pot one way.... and you move the nose up..... move the pot the other way and you move the nose down.  Simple.  ;)  So the trim wheel is a natural for adapting with butchering this little gamepad device.

If I weren't planning on a four engine throttle aircraft....... I could use the pots for one joystick as the throttles for two engines, one axis of the second mini joystick for the trim wheel, and the second axis of the second joystick for ........... hum......... something else that is "axis mapped" in the sim.  Not sure what right now.

best,

...........john

[JBaymore]

F-15C Strike Eagle Simulator Cockpit Project Site


Hi all.

I just came across this AMAZING website documenting Gene Buckle's efforts at creating an F-15C Strike Eagle simulator......... by using the cockpit and many parts from an actual crashed aircraft  :o  :o  :o.   He even has photos on the site of the actual crash of that exact aircraft at an airshow!

It is at the http://www.f15sim.com address.

The whole F-15C project is beautifully documented in extreme detail... has lots of photos..... and has lots of stuff that can be related to anyone making an effort at a simulated cockpit....at any level of desired realism and budget. The complexity of the REAL aircraft is very interesting to see.  The restoration is being done in "loving detail".

This obviously is a HIGH BUDGET operation.  But it is fun to read.  Enjoy  ;).

best,

....................john

[JBaymore]

Vchat20,

I am not really sure about that yet.  I still have to figure out the logic and the mechanics of that system.   The current problem for me is the TO/GA switch.  I am not sure that can be realistically modeled in a simple fashion without more sophisticated electronics.  It may just have to work like the TOGA keypress in FS2004.

The thrust reverser levers sort of just "double" the number of potentiometers and mechanical hardware that you'd need, I think.  My question to myself is does it have to work EXACTLY like a real thrust reverser....... or is it enough for the simulation/realism factor to just have a real world switch/lever to move to actuate it?

I feel that there is a real tendency when you first think about this to want to make EVERYTHING an exact dupilcate of a real aircraft.  Then you realize the complexity and cost of that idea (see the f-15 cockpit above).  And you start to realize that if it is somewhat close....... that may be enough.  As Will said in a post a while ago........ just having a slide or twist control as a throttle made a HUGE impact in "realism" over pressing the + and - keys for a throttle.

And if you make the cockpit a duplicate of a real plane....... if you fly another plane in the sim....... it'll feel all wrong.  As it is, for me modeling a cockpit of a generic large jet...... if I decide to fly the C172........ my guess is that it will be kinda' weird  ;).

best,

..................john