[simpits-tech] Switchs, Rotary and pot
Marv De Beque
simpits-tech@simpits.org
Mon, 19 Aug 2002 16:59:38 -0400
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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>> above
>>>> page.
>>>>>> Thanks!
>>>>>
>>>>> _______________________________________________
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>> above
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>>>>
>>>>
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