[simpits-tech] Switchs, Rotary and pot

Marv De Beque simpits-tech@simpits.org
Mon, 19 Aug 2002 18:29:54 -0400


COTS = Commercial-Off-The-Shelf

Ah, the analog and encoders.  I don't know how many you need because I
haven't got to that part of the design.

Okay, 1 (one) expansion board should cover all of your digital inputs
(buttons)

http://flightlink.com/epic/expansion.html

The output boards...

http://flightlink.com/epic/32output.html

will only service 32 outputs.  Therefore, 3 (three) output modules are
required.

I don't know how many encoders and pots you need, but the card is available
at:

http://flightlink.com/epic/rotary.html

As you see, it is expensive.

I believe you can add additional expansion modules to add more analog
channels (you get 16 with each expansion module.  At $85 each, that would be
cheaper.

Marv
-- 


> From: "Frank Riedel" <frank@rezultat.dk>
> Reply-To: simpits-tech@simpits.org
> Date: Mon, 19 Aug 2002 23:39:33 +0200
> To: <simpits-tech@simpits.org>
> Subject: Re: [simpits-tech] Switchs, Rotary and pot
> 
> ohh, whats COTS ??
> 
> :o)
> 
> Frank
> 
> ----- Original Message -----
> From: "Marv De Beque" <mdebeque@woh.rr.com>
> To: <simpits-tech@simpits.org>
> Sent: Monday, August 19, 2002 10:59 PM
> Subject: Re: [simpits-tech] Switchs, Rotary and pot
> 
> 
>> Frank,
>> 
>> If memory serves, you can get one input expansion module for all of the
>> switches.
>> 
>> For the annunciator lights, I think there are at least 72 active
>> annuciators.  Each output expansion module will handle 32.
>> 
>> Since output modules cost about $100 each, you will need a total of three
>> output module boards.  Gets pricey.
>> 
>> There are also several alphanumeric displays that need to be addressed.
> One
>> is the chaff-flare controls.  The other two are the DED and its derivative
>> on the right AUX panel.  The problem with these two is not driving them,
> but
>> there is not a COTS solution for these displays themself.
>> 
>> 
>> --
>> 
>> 
>>> From: "Frank Riedel" <frank@rezultat.dk>
>>> Reply-To: simpits-tech@simpits.org
>>> Date: Mon, 19 Aug 2002 22:07:17 +0200
>>> To: <simpits-tech@simpits.org>
>>> Subject: Re: [simpits-tech] Switchs, Rotary and pot
>>> 
>>> Hi All !
>>> 
>>> Can anybody tell me what module to buy to the EPIC
>>> so all of F16 button, lamps, rotary etc,. will be funcktional ?????
>>> 
>>> All the best
>>> Frank
>>> 
>>> ----- Original Message -----
>>> From: "Mark Doran" <msdoran@attbi.com>
>>> To: <simpits-tech@simpits.org>
>>> Sent: Tuesday, August 06, 2002 8:20 AM
>>> Subject: RE: [simpits-tech] Switchs, Rotary and pot
>>> 
>>> 
>>>> I've been thinking about this some lately too as I plow through the
> epic
>>>> (sic) task of EPL programming for a complete set of F-16 panels.  Left
>>>> side console and half the center console all done now, but I digress.
>>>> 
>>>> Encoders seem to get used (from a human factors-ish sort of view) where
>>>> you have knobs that turn without an end stop and where the knob fitted
>>>> doesn't need to line up with any particular markings on the panel that
>>>> it's mounted on.  Losing any one click 'cos you go by too fast isn't a
>>>> problem because you can always click on one more time in the same
>>>> direction to adjust...same for overshooting if you were really going
>>>> fast just go back a click or two...
>>>> 
>>>> For encoders, there's no real problem in syncing a physical mark on the
>>>> knob, like a stripe say, with an orientation versus the panel the knob
>>>> is on.  But if you need to sync in orientation or you need end stops on
>>>> travel of the knob in either direction, well then you definitely want a
>>>> rotary switch, not an encoder.
>>>> 
>>>> FWIW, I wonder about using pots in places where the real jet has
>>>> encoders (like HSI heading and course controls for example).  How do
> you
>>>> get around the fact that a pot has an end stop??  Ralph's default
>>>> keystroke to analog axis mapping technique gives you only 32 steps in
>>>> both up and down directions...not enough resolution steps if you are
>>>> doing compass headings, say.  Yes, you can hand code something to read
>>>> the pots absolute value to get more resolution in each of the 32
> "slots"
>>>> but that's a lot of code, I think you are still limited to ~256 steps
> of
>>>> resolution, and you still don't really have the right "feel" equivalent
>>>> given that an encoder just doesn't bump into an end stop.
>>>> 
>>>> Plus of course, there are already near enough more things that need
>>>> analog axes than you have to play with in the first place with a single
>>>> EPIC: 2 for stick, 5 for TQS, 1 for rudder, 1 for HUD brightness, 2 for
>>>> radio volumes, 2 for threat and sidewinder volume...that's 13 out of 16
>>>> possible max right there just for the controls I actually use a lot
> when
>>>> flying.  You certainly won't be using pots to replace all the rotary
>>>> knobs anyway ;-)  [Mmm, presuming you use EPIC for flight control axes
>>>> that is.]
>>>> 
>>>> Back to encoders though...
>>>> 
>>>> Electrically after all the complex circuitry is boiled down what you
> get
>>>> is on of two switch make pulses that mean either "clockwise" (CW) one
> or
>>>> "counter clockwise" (CCW) one.  A bit over simplified perhaps but
>>>> looking at this as a programmer that's what I see.
>>>> 
>>>> Now, I can't see why if you have a rotary mechanical switch that has no
>>>> end stop CW or CCW why you can't do a "software encoder" in EPL and
> save
>>>> lots of painful circuitry and wiring...not to mention cash.
>>>> 
>>>> How about this:
>>>> 
>>>> A three pole rotary switch with no end stops.  Wire each pole for a
>>>> separate EPIC mod/row/bit number for this example with bits in
>>>> "increasing" order clockwise:
>>>> 
>>>> --BEGIN EPL EXCERPT
>>>> 
>>>> // I haven't actually compiled and tried this but it's similar to the
>>>> code I
>>>> // have put together for positional rotary knobs that is working.
>>>> // this uses the newer "device" and function call syntax but
> translating
>>>> // back to EPICenter pre-v47 should also work well enough for this.
>>>> 
>>>> byte vLastPos = 0;
>>>> 
>>>> device(dFakeEncoder)
>>>> {
>>>> connector(FirstExpansionModule);
>>>> button(0, 0, bBit0);
>>>> button(0, 1, bBit1);
>>>> button(0, 2, bBit2);
>>>> };
>>>> 
>>>> void dFakeEncoder.bBit0.On(void)
>>>> {
>>>> if(vLastPos == 2) {
>>>> call(pulse_cw_keystroke);
>>>> } else if (vLastPos == 1) {
>>>> call(pulse_ccw_keystroke);
>>>> } // else we're confused so don't send key presses :-)
>>>> vLastPos = 0;
>>>> }
>>>> 
>>>> void dFakeEncoder.bBit1.On(void)
>>>> {
>>>> if(vLastPos == 0) {
>>>> call(pulse_cw_keystroke);
>>>> } else if (vLastPos == 2) {
>>>> call(pulse_ccw_keystroke);
>>>> } // else we're confused so don't send key presses :-)
>>>> vLastPos = 1;
>>>> }
>>>> 
>>>> void dFakeEncoder.bBit2.On(void)
>>>> {
>>>> if(vLastPos == 1) {
>>>> call(pulse_cw_keystroke);
>>>> } else if (vLastPos == 0) {
>>>> call(pulse_ccw_keystroke);
>>>> } // else we're confused so don't send key presses :-)
>>>> vLastPos = 2;
>>>> }
>>>> 
>>>> --END EPL EXCERPT
>>>> 
>>>> Ok, so the switch has only three positions but if you put a round knob
>>>> on it with no markings, who's to know??  It'll feel like an encoder
>>>> (ish).  In my testing with EPL code for rotary knobs that do have
>>>> positional line up requirements, EPL execution is plenty fast enough to
>>>> keep up with you even if you spin the knob pretty fast as you would
> with
>>>> an actual encoder.
>>>> 
>>>> The EPIC encoder module is quite spendy.  If this works it might save a
>>>> little that way.  Of course we may end up using some encoders in our
>>>> project since Falcon4 uses so many switches now the hardware may be on
> a
>>>> "switch count diet" to fit onto a single EPIC and encoders do seem to
>>>> use 1/3 less EPIC MRB namespace up when coding :-)
>>>> 
>>>> Cheers,
>>>> 
>>>> Mark.
>>>> 
>>>> 
>>>>> -----Original Message-----
>>>>> From: simpits-tech-admin@simpits.org [mailto:simpits-tech-
>>>>> admin@simpits.org] On Behalf Of Marv De Beque
>>>>> Sent: Monday, August 05, 2002 3:32 PM
>>>>> To: simpits-tech@simpits.org
>>>>> Subject: Re: [simpits-tech] Switchs, Rotary and pot
>>>>> 
>>>>> That is an open question.
>>>>> 
>>>>> The answer is, it depends.
>>>>> 
>>>>> However, you have not qualified the exact application, so it is hard
>>>> to
>>>>> give
>>>>> you a good answer.
>>>>> 
>>>>> However, since I am constructing a F-16 cockpit, I can tell you what I
>>>>> plan
>>>>> to use.  I will use a potentiometer for almost all of my applications
>>>>> where
>>>>> there is a knob.  Except....
>>>>> 
>>>>> ... the caveat is there are many knobs that use a rotary switch and I
>>>> will
>>>>> use a rotary switch where it is required.  I think you know what a
>>>> rotary
>>>>> switch is, but if not, it is a mechanical switch that rotates to
>>>> preset
>>>>> positions.
>>>>> 
>>>>> There are not too many places where an encoder will be applicable in
>>>> my
>>>>> sim.
>>>>> I may possibly use them for the ICP panel that sticks in the pilots
>>>> face.
>>>>> There are 4 thumb wheels that control contrast, brightness, and other
>>>>> functions on the HUD.  An encoder may be physically easier to mount
>>>> than a
>>>>> pot in those instances.
>>>>> 
>>>>> Encoders require more expensive circuitry to operate than a pot.
>>>> General
>>>>> rule of thumb is that there should be a good reason for using an
>>>> encoder
>>>>> where normally a pot will not do.
>>>>> 
>>>>> I would recommend a pot.
>>>>> 
>>>>> That being said, from the scope of the questions you are asking, I
>>>> wonder
>>>>> where you are at in your project and what your project goals are?  I
>>>> ask
>>>>> because I get a sense that you might be putting the cart before the
>>>> horse.
>>>>> 
>>>>> What is your goal and what is your plan to get there?
>>>>> 
>>>>> I am sure that you can get all the help you need right here, but it is
>>>>> good
>>>>> to get the basics first, outline your goals, and then we can help you
>>>>> execute your plan (or at least help you get a plan together).
>>>>> 
>>>>> Marv
>>>>> --
>>>>> 
>>>>> 
>>>>>> From: "Frank Riedel" <frank@rezultat.dk>
>>>>>> Reply-To: simpits-tech@simpits.org
>>>>>> Date: Tue, 6 Aug 2002 00:09:33 +0200
>>>>>> To: <simpits-tech@simpits.org>
>>>>>> Subject: Re: [simpits-tech] Switchs, Rotary and pot
>>>>>> 
>>>>>> Great exampels ;o)
>>>>>> GOT IT ;o)
>>>>>> BUT - can i use POT instead of ENCODERS in my pit ???
>>>>>> 
>>>>>> Frank
>>>>>> 
>>>>>> ----- Original Message -----
>>>>>> From: "Marv De Beque" <mdebeque@woh.rr.com>
>>>>>> To: <simpits-tech@simpits.org>
>>>>>> Sent: Monday, August 05, 2002 11:57 PM
>>>>>> Subject: Re: [simpits-tech] Switchs, Rotary and pot
>>>>>> 
>>>>>> 
>>>>>>> No.
>>>>>>> 
>>>>>>> A pot (short for potentiometer) is a device that rotates over a
>>>> given
>>>>>>> portion of a circle.  This is usually about 270 degrees, but there
>>>> are
>>>>>>> multi-turn pots that rotate 5, 10, or 20 turns from lock to lock.
>>>>>>> 
>>>>>>> A pot is nothing more than a resistor that can be changed from zero
>>>>>>> (usually) to its maximum value.  100,000 Ohms is typical for
>>>> simulator
>>>>>> use.
>>>>>>> 
>>>>>>> A pot, theoretically, has an infinite adjustment between its two
>>>>> extreme
>>>>>>> values (i.e., 0 to 100,000 Ohms).  So, like a faucet (in good
>>>> working
>>>>>>> order), you can adjust the flow to any value in between.
>>>>>>> 
>>>>>>> A rotary encoder is different.  It is a device that rotates like a
>>>> pot,
>>>>>> but
>>>>>>> instead of acting like a variable resistor, it sends out a set of
>>>>> pulses
>>>>>> as
>>>>>>> the knob turns.  It is sort of like putting playing cards on the
>>>> forks
>>>>> of
>>>>>> a
>>>>>>> bicycle and turning the wheel.  As each spoke passes, an audible
>>>> click
>>>>> is
>>>>>>> heard (a pulse).  You can count the pulses and then determine how
>>>> far
>>>>> the
>>>>>>> wheel has rotated.  You need two two playing cards slightly offset
>>>> in
>>>>> an
>>>>>>> angular fashion to tell which direction the wheel is rotating.  By
>>>>> looking
>>>>>>> at which card clicks first you can tell direction of spin.
>>>>>>> 
>>>>>>> The thing about encoders is that they have a "granularity".  Unlike
>>>> a
>>>>> pot
>>>>>>> which is infinite, there are finite steps to an encoder.  There may
>>>> be
>>>>> any
>>>>>>> number of steps you can get from a few to several hundred steps per
>>>>>>> revolution.  You can resolve the rotation only down to the step,
>>>> but
>>>>> you
>>>>>> can
>>>>>>> not tell how much an encoder rotates between step steps (i.e., a
>>>> half
>>>>>> step).
>>>>>>> 
>>>>>>> Most encoders do not remember their positions when power to the
>>>> system
>>>>> is
>>>>>>> turned off.  So, the system must somehow save the last known
>>>> position
>>>>> if
>>>>>> it
>>>>>>> is to pick up where it left off at power down.  A pot has the same
>>>>>>> resistance whether the system has power or not.
>>>>>>> 
>>>>>>> A pot almost always has a mechanical stop.  Resistance can only go
>>>> so
>>>>> far.
>>>>>>> An encoder does not necessarily have a mechanical stop and can be
>>>>> rotated
>>>>>>> continuously without stopping.
>>>>>>> 
>>>>>>> An example of an encoder is a computer mouse (at least the old
>>>> ones).
>>>>>> Some
>>>>>>> new car stereos have them too.
>>>>>>> 
>>>>>>> Two different animals that can be used in similar ways and each has
>>>> its
>>>>>>> advantages.
>>>>>>> 
>>>>>>> Sorry for the long message, but I am short on time.
>>>>>>> 
>>>>>>> Marv
>>>>>>> --
>>>>>>> 
>>>>>>> 
>>>>>>>> From: "Frank Riedel" <frank@rezultat.dk>
>>>>>>>> Reply-To: simpits-tech@simpits.org
>>>>>>>> Date: Mon, 5 Aug 2002 23:35:45 +0200
>>>>>>>> To: <simpits-tech@simpits.org>
>>>>>>>> Subject: Re: [simpits-tech] Switchs, Rotary and pot
>>>>>>>> 
>>>>>>>> Thanks alot for the explanation ;o)
>>>>>>>> 
>>>>>>>> I found the F16 panels at simpits.org...
>>>>>>>> 
>>>>>>>> Did i get it right - rotary encoders = potentiometers ??
>>>>>>>> 
>>>>>>>> Thanks
>>>>>>>> Frank !
>>>>>>>> 
>>>>>>>> ----- Original Message -----
>>>>>>>> From: "Andreas Fransson" <andreas.fransson@post.utfors.se>
>>>>>>>> To: <simpits-tech@simpits.org>
>>>>>>>> Sent: Monday, August 05, 2002 9:09 PM
>>>>>>>> Subject: Re: [simpits-tech] Switchs, Rotary and pot
>>>>>>>> 
>>>>>>>> 
>>>>>>>>> Frank,
>>>>>>>>> 
>>>>>>>>> 3-way switches are (usually) on-off-on. With or without automatic
>>>>>> return
>>>>>>>> to
>>>>>>>>> center position (not sure what the english expression for this
>>>> would
>>>>>> be).
>>>>>>>>> 
>>>>>>>>> Rotaries, if you mean rotary switches and not rotary encoders,
>>>> may or
>>>>>> may
>>>>>>>>> not have limits. A couple I have here for example do not. They go
>>>> all
>>>>>> the
>>>>>>>>> way around. What they do is just rotate a common ground around a
>>>>> number
>>>>>> of
>>>>>>>>> connections. Like a "normal" switch but with many more positions.
>>>>> Mine
>>>>>>>> have
>>>>>>>>> 12 I think. You could say that they are "all-on" in the sense
>>>> that
>>>>> one
>>>>>>>> lead
>>>>>>>>> is always active. Encoders are a different breed altogether. They
>>>> are
>>>>>>>>> commonly used to sense motion (rotation) rather than indicate
>>>> switch
>>>>>>>>> positions.
>>>>>>>>> 
>>>>>>>>> "Pots", or potentiometers, are basically variable resistors. I
>>>> you
>>>>> use
>>>>>> one
>>>>>>>>> with EPIC, or as a replacement for a joystick pot, it is 100 ohm
>>>>> linear
>>>>>>>> pots
>>>>>>>>> you want.
>>>>>>>>> 
>>>>>>>>> If you use the EPIC, the kind of switches you use are almost
>>>>>> unimportant.
>>>>>>>>> EPL (the EPIC programming language) is very flexible. It's not at
>>>> all
>>>>>> like
>>>>>>>>> the standard joystick momentary on/off pushbuttons.
>>>>>>>>> 
>>>>>>>>> What aircraft (or whatever) panels are you looking for?
>>>>>>>>> 
>>>>>>>>> Andreas
>>>>>>>>> http://valhallainc.d2g.com
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> From: "Frank Riedel" <frank@rezultat.dk>
>>>>>>>>>> Hi All !
>>>>>>>>>> 
>>>>>>>>>> 3 way switchs - is that off-on-off  or ????
>>>>>>>>>> Rotary - is that 360 dg. or ???
>>>>>>>>>> 2 way switchs - is that on-on  or ???
>>>>>>>>>> Pot - is that a normal potmeter 100 ohm or  ???
>>>>>>>>>> Is EPIC control all those switchs nomatter if it is on-of or
>>>> on-on
>>>>> ???
>>>>>>>>>> 
>>>>>>>>>> Do anyone of you guys have a link to a page where i can read
>>>> about
>>>>> it
>>>>>>>> ???
>>>>>>>>>> 
>>>>>>>>>> and do anyone have a set of drawings of panels without knobs on
>>>> ????
>>>>>>>>>> 
>>>>>>>>>> thanks for all your help... i'm on the road for my first real
>>>> pit
>>>>> ;o)
>>>>>>>>>> 
>>>>>>>>>> Frank
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> _______________________________________________
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>>>>>>>>> Simpits-tech@simpits.org
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>>>>> above
>>>>>>>> page.  Thanks!
>>>>>>>> 
>>>>>>>> 
>>>>>>>> _______________________________________________
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>>>>>>>> Thanks!
>>>>>>> 
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>>>>> 
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