[simpits-tech] Avionics knobs
Alan D. Mazurka
simpits-tech@simpits.org
Thu, 24 Oct 2002 12:39:15 -0400
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hi,
this might be a tad premature, but....
many folks have this need, and i was very disappointed with the most
popular offerings out there.
a friend of mine has worked with me to develop a PIC-based rotary which
outputs a well-formed 20msec pulse suitable for Hagstrom (and probably
Epic, not tested yet)
we use grayhill encoders, and the design accepts 12, 24, and 36 step
devices. it has an excellent "hand feel", and all the components are
mounted right behind the rotary, so there is no external card to connect
with. we have several prototypes, and are close to etching the first batch
of beta units. they are static protected, reverse-connection protected, and
have caps across the processor for filtering. a nice, tight design.
the "other" project (much more mature software-wise) is based on a
mechanical rotary switch. it's a 12-position switch which has an internal
stop which lets you make it assume any number of positions. i needed this
for throttles in a train simulator - one provides 8 steps
throttle, another provides 9 steps brake. it only uses 2 hagstrom lines:
the processor makes the switch behave just like a rotary.
i have since discovered it could be useful for many applications where you
do not want a knob to continuously spin. it has a "strong" force, with an
assuring "click" - much stronger than the rotaries. it has been rock-solid
in execution.
at some point, i would like to work with a few "beta" testers for their
input. because it's processor-based, we can tailor the response.
i'm curious about how many people might be interested in this tidbit, and
what they would want from an "ideal" encoder.
- adm -
At 12:22 AM 10/24/02 -0500, you wrote:
>Been trying to find some knobs to use to tune radios in X-Plane. X-Plane
>has a key for tune up and another key for tune down. So, I thought I
>could simply get a ratchet type switch or a switch with a tab in it that
>has two sets of contacts...one would make contact momentarily when the
>knob is turned one way, the other contacts would make contact
>momentarily when the knob is turned the other way. No luck at RadioShack
>or the local electronics shop. I thought perhaps the tuner knobs in some
>80s model cars might work, the ones that have a regular knob to tune the
>radio but have a digital display of the frequency. Does anyone know how
>the knobs in a typical real aviation radio work (the kind with the
>digital display)? Are they encoders or something?
>
>I'm curious about how other people are doing this.
>
> -Matt Bailey
----------
Alan D. Mazurka Webspace Design & Implementation
adm.design@verizon.net
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hi,<br><br>
this might be a tad premature, but....<br><br>
many folks have this need, and i was very disappointed with the most
popular offerings out there.<br><br>
a friend of mine has worked with me to develop a PIC-based rotary which
outputs a well-formed 20msec pulse suitable for Hagstrom (and probably
Epic, not tested yet)<br><br>
we use grayhill encoders, and the design accepts 12, 24, and 36 step
devices. it has an excellent "hand feel", and all the
components are mounted right behind the rotary, so there is no external
card to connect with. we have several prototypes, and are close to
etching the first batch of beta units. they are static protected,
reverse-connection protected, and have caps across the processor for
filtering. a nice, tight design. <br><br>
the "other" project (much more mature software-wise) is based
on a mechanical rotary switch. it's a 12-position switch which has an
internal stop which lets you make it assume any number of positions. i
needed this for throttles in a train simulator - one provides 8 steps
throttle, another provides 9 steps brake. it only uses 2 hagstrom
lines: the processor makes the switch behave just like a
rotary.<br><br>
i have since discovered it could be useful for many applications where
you do not want a knob to continuously spin. it has a "strong"
force, with an assuring "click" - much stronger than the
rotaries. it has been rock-solid in execution.<br><br>
at some point, i would like to work with a few "beta" testers
for their input. because it's processor-based, we can tailor the
response.<br><br>
i'm curious about how many people might be interested in this tidbit, and
what they would want from an "ideal" encoder.<br><br>
- adm -<br><br>
At 12:22 AM 10/24/02 -0500, you wrote:<br><br>
<blockquote type=cite class=cite cite>Been trying to find some knobs to
use to tune radios in X-Plane. X-Plane<br>
has a key for tune up and another key for tune down. So, I thought
I<br>
could simply get a ratchet type switch or a switch with a tab in it
that<br>
has two sets of contacts...one would make contact momentarily when
the<br>
knob is turned one way, the other contacts would make contact<br>
momentarily when the knob is turned the other way. No luck at
RadioShack<br>
or the local electronics shop. I thought perhaps the tuner knobs in
some<br>
80s model cars might work, the ones that have a regular knob to tune
the<br>
radio but have a digital display of the frequency. Does anyone know
how<br>
the knobs in a typical real aviation radio work (the kind with the<br>
digital display)? Are they encoders or something?<br><br>
I'm curious about how other people are doing this.<br><br>
<x-tab> </x-tab>-Matt
Bailey</blockquote>
<x-sigsep><p></x-sigsep>
<hr>
<br>
Alan D.
Mazurka
Webspace Design & Implementation<br>
adm.design@verizon.net <br>
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