Today's Message Index:
----------------------
1. 05:19 AM - Re: Re: Constructing an automatic RCA video camera feed splitter (Alec Myers)
2. 05:31 AM - Re: Re: Constructing an automatic RCA video camera feed splitter (Charlie England)
3. 05:42 AM - Re: Re: Constructing an automatic RCA video camera feed splitter (Alec Myers)
4. 08:23 AM - Re: Re: Constructing an automatic RCA video camera feed splitter (Robert L. Nuckolls, III)
5. 08:38 AM - Re: Re: Constructing an automatic RCA video camera feed splitter (Alec Myers)
6. 08:51 AM - Re: Re: Constructing an automatic RCA video camera feed splitter (Charlie England)
7. 09:12 AM - Re: Re: Constructing an automatic RCA video camera feed splitter (Alec Myers)
8. 10:28 AM - Re: Re: Constructing an automatic RCA video camera feed splitter (Bill)
9. 12:19 PM - Re: Re: Constructing an automatic RCA video camera feed splitter (Robert L. Nuckolls, III)
10. 12:34 PM - Re: Re: Constructing an automatic RCA video camera feed splitter (Alec Myers)
11. 01:06 PM - Re: Re: Constructing an automatic RCA video camera feed splitter (Paul A. Fisher)
12. 08:01 PM - Re: Constructing an automatic RCA video camera feed splitter (Eric Page)
13. 08:07 PM - Re: Constructing an automatic RCA video camera feed splitter (Eric Page)
14. 08:44 PM - Re: Re: Constructing an automatic RCA video camera feed splitter (Alec Myers)
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
Another possible gotcha:
The AD8184 doesnt do any kind of video buffering, and the various video sources
are not frame-locked. (In this scenario there is no 60Hz ac for the camera to
sync to). So what the effect of switching sources will be is uncertain. Depending
on the video display it could be anything from an unnoticeable half frame
glitch to several seconds of rolling display before it locks into the new frame
source.
Its definitely worth experimenting before settling on the final parts list.
On Oct 15, 2017, at 00:43, Alec Myers <alec@alecmyers.com> wrote:
If you use a PIC, you could (trivially) do the following:
Hold the button down for ten seconds to enter programming mode. Press the button
briefly x times to set the scan period at x seconds. Press the button for two
seconds to exit programming mode.
No need for resistors at all.
> On Oct 14, 2017, at 8:38 PM, Eric Page <edpav8r@yahoo.com> wrote:
>
>
> Wade,
>
> Question: do you want to be able to adjust the scan rate as a matter of routine
operation (i.e. with a panel-mounted knob), or do you envision setting the
rate where you like it at installation, and leaving it alone?
>
> The answer will dictate whether we put a small trimmer potentiometer on the circuit
board or design for a larger panel-mounted potentiometer and knob.
>
> Eric
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=473556#473556
>
>
>
>
>
>
>
>
>
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
That stuff is cool as far as programming tricks go, but who will be able to
use the hardware except the original designer? I, and everyone else on this
list, have owned dozens of electronic gadgets over the years that are
absolutely impossible to set up and use without the
English-as-a-second-language printed manual that you can't find after the
1st month of ownership. I have to use google on my desktop to explore how
to get my phone apps to work like I want.
Just something to consider, when designing for general use instead
specifically trained fighter pilots or astronauts.
On Sat, Oct 14, 2017 at 11:43 PM, Alec Myers <alec@alecmyers.com> wrote:
>
> If you use a PIC, you could (trivially) do the following:
>
> Hold the button down for ten seconds to enter programming mode. Press the
> button briefly x times to set the scan period at x seconds. Press the
> button for two seconds to exit programming mode.
>
> No need for resistors at all.
>
>
> > On Oct 14, 2017, at 8:38 PM, Eric Page <edpav8r@yahoo.com> wrote:
> >
> >
> > Wade,
> >
> > Question: do you want to be able to adjust the scan rate as a matter of
> routine operation (i.e. with a panel-mounted knob), or do you envision
> setting the rate where you like it at installation, and leaving it alone?
> >
> > The answer will dictate whether we put a small trimmer potentiometer on
> the circuit board or design for a larger panel-mounted potentiometer and
> knob.
> >
> > Eric
> >
>
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
Yes, you do have to make it usable.
But =9Cpush to advance, push-and-hold to cycle=9D is fairly str
aightforward. (If that=99s too complex, do you really want to fly with
this person?!)
When it comes to changing the cycle period I=99m confident that a one-
button interface can be very straightforward for that too. Certainly easier t
han opening the panel to adjust a twiddle pot, or getting out a soldering ir
on. A panel pot is simplest, but do you really want to drill your panel for a
control you=99re going to set on day one and then forget about?
So, it=99s not about tricks. It=99s about tucking away seldom us
ed functions but still having them at your finger tips.
On Oct 15, 2017, at 08:30, Charlie England <ceengland7@gmail.com> wrote:
That stuff is cool as far as programming tricks go, but who will be able to u
se the hardware except the original designer? I, and everyone else on this l
ist, have owned dozens of electronic gadgets over the years that are absolut
ely impossible to set up and use without the English-as-a-second-language pr
inted manual that you can't find after the 1st month of ownership. I have to
use google on my desktop to explore how to get my phone apps to work like I
want.
Just something to consider, when designing for general use instead specifica
lly trained fighter pilots or astronauts.
> On Sat, Oct 14, 2017 at 11:43 PM, Alec Myers <alec@alecmyers.com> wrote:
>
> If you use a PIC, you could (trivially) do the following:
>
> Hold the button down for ten seconds to enter programming mode. Press the b
utton briefly x times to set the scan period at x seconds. Press the button f
or two seconds to exit programming mode.
>
> No need for resistors at all.
>
>
> > On Oct 14, 2017, at 8:38 PM, Eric Page <edpav8r@yahoo.com> wrote:
> >
> >
> > Wade,
> >
> > Question: do you want to be able to adjust the scan rate as a matter of r
outine operation (i.e. with a panel-mounted knob), or do you envision settin
g the rate where you like it at installation, and leaving it alone?
> >
> > The answer will dictate whether we put a small trimmer potentiometer on t
he circuit board or design for a larger panel-mounted potentiometer and knob
.
> >
> > Eric
> >
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
At 07:30 AM 10/15/2017, you wrote:
>That stuff is cool as far as programming tricks go, but who will be
>able to use the hardware except the original designer? I, and
>everyone else on this list, have owned dozens of electronic gadgets
>over the years that are absolutely impossible to set up and use
>without the English-as-a-second-language printed manual that you
>can't find after the 1st month of ownership. I have to use google on
>my desktop to explore how to get my phone apps to work like I want.
This is amongst the simplest PIC applications we'll
ever encounter . . . once the first installation
has combed out the nits . . . it seems unlikely
that there would be many if any software upgrades.
Another consideration is flexibility. Suppose the
prospective end user wants only two cameras . . . or
three? Different software . . . or strapped selection
on the ECB?
Then there's a matter of packaging. One can easily
spend more time putting a gizmo in a box and installing
it than it took to build the gizmo. Certainly, packaging
issues are a major component of a development project.
A possibility for this project is to package in a
D-sub housing. The enclosure is an off-the-shelf, inexpensive
product that simply snaps onto the final assembly.
An ECB can be soldered directly into the gap between
rows of solder-cups on a dsub.
Emacs!
and dropped into a plastic housing that simply
snaps together. A product housed in a 15 pin
back shell has these dimensions.
Emacs!
This project can probably be fitted into a
25 pin back shell. I perceive no particular
advantage in taking power and signals on/off
the board on RCA jacks . . . shielded
wires are just as easily dropped onto d-sub
pins. RCA plugs are not the most installer
friendly connectors.
With the extra pins, the user could intall
jumpers on the connector to select 2, 3 or 4
cameras. Other jumpers might select 3, 4 or
5 seconds per step . . . etc.
Then there's consideration for the constellation
of end users. How many would even be willing,
much less able to successfully assemble the
thing? Companies I've worked for have often
been very protective of details for how their
product was put together . . . worries about
people wanting to build it themselves. I've
observed that the $cost$ to built one-off
exceeds the selling price from a manufacturer
who is set up to build in volume while working
wayyyyyyy down on the learning curve.
It seems likely that the best way to bring
this project into the marketplace is to have
it productionized after the initial development
work is completed.
Even if supported by availability of bare
ecbs and programmed chips, it doesn't seem
like many of these things would be built.
Bob . . .
Message 5
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
The AD8184 is $8. Here=99s a project using $0.50 bus switch chips:
https://hackaday.com/2007/03/14/diy-av-switch/
For our purpose the PIC does its own demux - one output pin per camera.
Benefits:
-2,3,5, however-many cameras, all equally simple.
- You don=99t need to sequence cameras in order or equally, thus you c
an have forward, left wing, forward, right wing as the sequence.
Thoughts?
On Oct 15, 2017, at 11:22, Robert L. Nuckolls, III <nuckolls.bob@aeroelectri
c.com> wrote:
At 07:30 AM 10/15/2017, you wrote:
> That stuff is cool as far as programming tricks go, but who will be able t
o use the hardware except the original designer? I, and everyone else on thi
s list, have owned dozens of electronic gadgets over the years that are abso
lutely impossible to set up and use without the English-as-a-second-language
printed manual that you can't find after the 1st month of ownership. I have
to use google on my desktop to explore how to get my phone apps to work lik
e I want.
This is amongst the simplest PIC applications we'll
ever encounter . . . once the first installation
has combed out the nits . . . it seems unlikely
that there would be many if any software upgrades.
Another consideration is flexibility. Suppose the
prospective end user wants only two cameras . . . or
three? Different software . . . or strapped selection
on the ECB?
Then there's a matter of packaging. One can easily
spend more time putting a gizmo in a box and installing
it than it took to build the gizmo. Certainly, packaging
issues are a major component of a development project.
A possibility for this project is to package in a
D-sub housing. The enclosure is an off-the-shelf, inexpensive
product that simply snaps onto the final assembly.
An ECB can be soldered directly into the gap between
rows of solder-cups on a dsub.
<aabd0be.jpg>
and dropped into a plastic housing that simply
snaps together. A product housed in a 15 pin
back shell has these dimensions.
<aabd0dd.jpg>
This project can probably be fitted into a
25 pin back shell. I perceive no particular
advantage in taking power and signals on/off
the board on RCA jacks . . . shielded
wires are just as easily dropped onto d-sub
pins. RCA plugs are not the most installer
friendly connectors.
With the extra pins, the user could intall
jumpers on the connector to select 2, 3 or 4
cameras. Other jumpers might select 3, 4 or
5 seconds per step . . . etc.
Then there's consideration for the constellation
of end users. How many would even be willing,
much less able to successfully assemble the
thing? Companies I've worked for have often
been very protective of details for how their
product was put together . . . worries about
people wanting to build it themselves. I've
observed that the $cost$ to built one-off
exceeds the selling price from a manufacturer
who is set up to build in volume while working
wayyyyyyy down on the learning curve.
It seems likely that the best way to bring
this project into the marketplace is to have
it productionized after the initial development
work is completed.
Even if supported by availability of bare
ecbs and programmed chips, it doesn't seem
like many of these things would be built.
Bob . . .
Message 6
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
Bob,
My comment was about 'buttonology'; not building. I've got a little clock
that's RF linked to Federal time broadcasts. It's totally impossible to
use any of the elaborate built-in functions with out the manual, because it
has two or three unmarked buttons, and to access the various functions, you
need to know the "combination". No one can use the thing without the book
in front of them. Same thing for most kilo-function watches, etc. Even my
old Icom A-4 handheld comm is like that. I seldom use it, so even though
I've owned it for over 20 years, I still don't know how to program
frequencies into it. If it had a keypad, anyone could pick it up and enter
'122.75', or '125.25', etc. But since it doesn't, the unwashed can only
hold the up or down button until they see the freq they want. For me, a
perfect example of something simplified to the point of un-usability.
Charlie
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On Sun, Oct 15, 2017 at 10:22 AM, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 07:30 AM 10/15/2017, you wrote:
>
> That stuff is cool as far as programming tricks go, but who will be able
> to use the hardware except the original designer? I, and everyone else on
> this list, have owned dozens of electronic gadgets over the years that are
> absolutely impossible to set up and use without the
> English-as-a-second-language printed manual that you can't find after the
> 1st month of ownership. I have to use google on my desktop to explore how
> to get my phone apps to work like I want.
>
>
> This is amongst the simplest PIC applications we'll
> ever encounter . . . once the first installation
> has combed out the nits . . . it seems unlikely
> that there would be many if any software upgrades.
>
> Another consideration is flexibility. Suppose the
> prospective end user wants only two cameras . . . or
> three? Different software . . . or strapped selection
> on the ECB?
>
> Then there's a matter of packaging. One can easily
> spend more time putting a gizmo in a box and installing
> it than it took to build the gizmo. Certainly, packaging
> issues are a major component of a development project.
>
> A possibility for this project is to package in a
> D-sub housing. The enclosure is an off-the-shelf, inexpensive
> product that simply snaps onto the final assembly.
> An ECB can be soldered directly into the gap between
> rows of solder-cups on a dsub.
>
> [image: Emacs!]
>
> and dropped into a plastic housing that simply
> snaps together. A product housed in a 15 pin
> back shell has these dimensions.
>
> [image: Emacs!]
>
> This project can probably be fitted into a
> 25 pin back shell. I perceive no particular
> advantage in taking power and signals on/off
> the board on RCA jacks . . . shielded
> wires are just as easily dropped onto d-sub
> pins. RCA plugs are not the most installer
> friendly connectors.
>
> With the extra pins, the user could intall
> jumpers on the connector to select 2, 3 or 4
> cameras. Other jumpers might select 3, 4 or
> 5 seconds per step . . . etc.
>
> Then there's consideration for the constellation
> of end users. How many would even be willing,
> much less able to successfully assemble the
> thing? Companies I've worked for have often
> been very protective of details for how their
> product was put together . . . worries about
> people wanting to build it themselves. I've
> observed that the $cost$ to built one-off
> exceeds the selling price from a manufacturer
> who is set up to build in volume while working
> wayyyyyyy down on the learning curve.
>
> It seems likely that the best way to bring
> this project into the marketplace is to have
> it productionized after the initial development
> work is completed.
>
> Even if supported by availability of bare
> ecbs and programmed chips, it doesn't seem
> like many of these things would be built.
>
> Bob . . .
>
Message 7
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
It=99s an open offer to the group (I would enjoy contributing
something) - if you=99d like some PIC code along the lines I
suggested - one or maybe two buttons, with or without a rotary encoder
(that would be my favourite solution) I can have it done by the end of
the week, if Paul doesn=99t want to. That=99s a 1990=99s
technology solution.
If the group is more comfortable with a 555 and discrete components (a
creditable 70=99s technology solution) then there=99s no
need for software.
The choice of interface - number of buttons or switches, panel mount
speed control etc. really is down to the person who=99s going to
be installing it, we should let them pick what they want.
> On Oct 15, 2017, at 11:50 AM, Charlie England <ceengland7@gmail.com>
wrote:
>
> Bob,
>
> My comment was about 'buttonology'; not building. I've got a little
clock that's RF linked to Federal time broadcasts. It's totally
impossible to use any of the elaborate built-in functions with out the
manual, because it has two or three unmarked buttons, and to access the
various functions, you need to know the "combination". No one can use
the thing without the book in front of them. Same thing for most
kilo-function watches, etc. Even my old Icom A-4 handheld comm is like
that. I seldom use it, so even though I've owned it for over 20 years, I
still don't know how to program frequencies into it. If it had a keypad,
anyone could pick it up and enter '122.75', or '125.25', etc. But since
it doesn't, the unwashed can only hold the up or down button until they
see the freq they want. For me, a perfect example of something
simplified to the point of un-usability.
>
> Charlie
>
>
<https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_
campaign=sig-email&utm_content=webmail&utm_term=icon>
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>
> On Sun, Oct 15, 2017 at 10:22 AM, Robert L. Nuckolls, III
<nuckolls.bob@aeroelectric.com <mailto:nuckolls.bob@aeroelectric.com>>
wrote:
> At 07:30 AM 10/15/2017, you wrote:
>> That stuff is cool as far as programming tricks go, but who will be
able to use the hardware except the original designer? I, and everyone
else on this list, have owned dozens of electronic gadgets over the
years that are absolutely impossible to set up and use without the
English-as-a-second-language printed manual that you can't find after
the 1st month of ownership. I have to use google on my desktop to
explore how to get my phone apps to work like I want.
>
> This is amongst the simplest PIC applications we'll
> ever encounter . . . once the first installation
> has combed out the nits . . . it seems unlikely
> that there would be many if any software upgrades.
>
> Another consideration is flexibility. Suppose the
> prospective end user wants only two cameras . . . or
> three? Different software . . . or strapped selection
> on the ECB?
>
> Then there's a matter of packaging. One can easily
> spend more time putting a gizmo in a box and installing
> it than it took to build the gizmo. Certainly, packaging
> issues are a major component of a development project.
>
> A possibility for this project is to package in a
> D-sub housing. The enclosure is an off-the-shelf, inexpensive
> product that simply snaps onto the final assembly.
> An ECB can be soldered directly into the gap between
> rows of solder-cups on a dsub.
>
> <aabd0be.jpg>
>
> and dropped into a plastic housing that simply
> snaps together. A product housed in a 15 pin
> back shell has these dimensions.
>
> <aabd0dd.jpg>
>
> This project can probably be fitted into a
> 25 pin back shell. I perceive no particular
> advantage in taking power and signals on/off
> the board on RCA jacks . . . shielded
> wires are just as easily dropped onto d-sub
> pins. RCA plugs are not the most installer
> friendly connectors.
>
> With the extra pins, the user could intall
> jumpers on the connector to select 2, 3 or 4
> cameras. Other jumpers might select 3, 4 or
> 5 seconds per step . . . etc.
>
> Then there's consideration for the constellation
> of end users. How many would even be willing,
> much less able to successfully assemble the
> thing? Companies I've worked for have often
> been very protective of details for how their
> product was put together . . . worries about
> people wanting to build it themselves. I've
> observed that the $cost$ to built one-off
> exceeds the selling price from a manufacturer
> who is set up to build in volume while working
> wayyyyyyy down on the learning curve.
>
> It seems likely that the best way to bring
> this project into the marketplace is to have
> it productionized after the initial development
> work is completed.
>
> Even if supported by availability of bare
> ecbs and programmed chips, it doesn't seem
> like many of these things would be built.
>
> Bob . . .
>
>
Message 8
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
Ditto Charlie!
do not archive
On Sun, Oct 15, 2017 at 8:50 AM, Charlie England <ceengland7@gmail.com>
wrote:
> Bob,
>
> My comment was about 'buttonology'; not building. I've got a little clock
> that's RF linked to Federal time broadcasts. It's totally impossible to
> use any of the elaborate built-in functions with out the manual, because it
> has two or three unmarked buttons, and to access the various functions, you
> need to know the "combination". No one can use the thing without the book
> in front of them. Same thing for most kilo-function watches, etc. Even my
> old Icom A-4 handheld comm is like that. I seldom use it, so even though
> I've owned it for over 20 years, I still don't know how to program
> frequencies into it. If it had a keypad, anyone could pick it up and enter
> '122.75', or '125.25', etc. But since it doesn't, the unwashed can only
> hold the up or down button until they see the freq they want. For me, a
> perfect example of something simplified to the point of un-usability.
>
> Charlie
>
>
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free.
> www.avast.com
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link>
> <#m_3036080108603840177_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>
> On Sun, Oct 15, 2017 at 10:22 AM, Robert L. Nuckolls, III <
> nuckolls.bob@aeroelectric.com> wrote:
>
>> At 07:30 AM 10/15/2017, you wrote:
>>
>> That stuff is cool as far as programming tricks go, but who will be able
>> to use the hardware except the original designer? I, and everyone else on
>> this list, have owned dozens of electronic gadgets over the years that are
>> absolutely impossible to set up and use without the
>> English-as-a-second-language printed manual that you can't find after the
>> 1st month of ownership. I have to use google on my desktop to explore how
>> to get my phone apps to work like I want.
>>
>>
>> This is amongst the simplest PIC applications we'll
>> ever encounter . . . once the first installation
>> has combed out the nits . . . it seems unlikely
>> that there would be many if any software upgrades.
>>
>> Another consideration is flexibility. Suppose the
>> prospective end user wants only two cameras . . . or
>> three? Different software . . . or strapped selection
>> on the ECB?
>>
>> Then there's a matter of packaging. One can easily
>> spend more time putting a gizmo in a box and installing
>> it than it took to build the gizmo. Certainly, packaging
>> issues are a major component of a development project.
>>
>> A possibility for this project is to package in a
>> D-sub housing. The enclosure is an off-the-shelf, inexpensive
>> product that simply snaps onto the final assembly.
>> An ECB can be soldered directly into the gap between
>> rows of solder-cups on a dsub.
>>
>> [image: Emacs!]
>>
>> and dropped into a plastic housing that simply
>> snaps together. A product housed in a 15 pin
>> back shell has these dimensions.
>>
>> [image: Emacs!]
>>
>> This project can probably be fitted into a
>> 25 pin back shell. I perceive no particular
>> advantage in taking power and signals on/off
>> the board on RCA jacks . . . shielded
>> wires are just as easily dropped onto d-sub
>> pins. RCA plugs are not the most installer
>> friendly connectors.
>>
>> With the extra pins, the user could intall
>> jumpers on the connector to select 2, 3 or 4
>> cameras. Other jumpers might select 3, 4 or
>> 5 seconds per step . . . etc.
>>
>> Then there's consideration for the constellation
>> of end users. How many would even be willing,
>> much less able to successfully assemble the
>> thing? Companies I've worked for have often
>> been very protective of details for how their
>> product was put together . . . worries about
>> people wanting to build it themselves. I've
>> observed that the $cost$ to built one-off
>> exceeds the selling price from a manufacturer
>> who is set up to build in volume while working
>> wayyyyyyy down on the learning curve.
>>
>> It seems likely that the best way to bring
>> this project into the marketplace is to have
>> it productionized after the initial development
>> work is completed.
>>
>> Even if supported by availability of bare
>> ecbs and programmed chips, it doesn't seem
>> like many of these things would be built.
>>
>> Bob . . .
>>
>
>
Message 9
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
At 12:26 PM 10/15/2017, you wrote:
>Ditto Charlie!
>
>do not archive
>
>On Sun, Oct 15, 2017 at 8:50 AM, Charlie England
><<mailto:ceengland7@gmail.com>ceengland7@gmail.com> wrote:
>Bob,
>
>My comment was about 'buttonology'; not
>building. I've got a little clock that's RF
>linked=C2 to Federal time broadcasts. It's
>totally impossible to use any of the elaborate
>built-in functions with out the manual, because
>it has two or three unmarked buttons, and to
>access the various functions, you need to know
>the "combination". No one can use the thing
>without the book in front of them. Same thing
>for most kilo-function watches, etc. Even my old
>Icom A-4 handheld comm is like that. I seldom
>use it, so even though I've owned it for over 20
>years, I still don't know how to program
>frequencies into it. If it had a keypad, anyone
>could pick it up and enter '122.75', or
>'125.25', etc. But since it doesn't, the
>unwashed can only hold the up or down button
>until they see the freq they want. For me, a
>perfect example of something simplified to the point of un-usability.
Understand. The task before us doesn't
present much of either programming or
a control task. The trade offs between
a two-position, spring-loaded switch
and a single push-button are valid
options where a the cadence of button
ops will transition between scan and
select modes.
I sympathize with your frustration on
the radio. I've been purchasing some VERY
capable but cumbersomely programmed UHF
transceivers and setting them up for our EMS crews
to monitor the local hospital repeater.
These radios will do lots of cool stuff
but you need to learn how to do a hat-dance
on the controls which consist of 6 push-buttons
and a knob. Fortunately, I'm only setting
them up for one frequency and then locking
the controls. They can be programmed via
serial cable and a utility that runs under
Windows . . . I may explore that feature
in due course. But in the mean time, the
hat-dance tune for one frequency is simple
and short.
Bob . . .
Message 10
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
One of the difficulties of a project like this is that there=99s
no clear design priority for those who=99d like to contribute.
I=99ve designed and built a *lot* of hobby PIC projects (the first
in 1996, I think) and sold a few too. I=99ve always tried to
reduce the BoM to a minimum (compatible with the task) which means:
- wringing absolutely the most out of a low functionality PIC with good
code
- minimizing connectors and controls - always way less reliable and more
expensive than any other part both in money and time
As the saying goes, an engineer is someone who can make for a penny what
any fool can make for a pound.
But that may not be the right priority here. Perhaps ease of
construction, wider sense of =9Cownership=9D,
adjustability-with-a-hot-soldering-iron are all more important.
> On Oct 15, 2017, at 3:19 PM, Robert L. Nuckolls, III
<nuckolls.bob@aeroelectric.com> wrote:
>
> At 12:26 PM 10/15/2017, you wrote:
>> Ditto Charlie!
>>
>> do not archive
>>
>> On Sun, Oct 15, 2017 at 8:50 AM, Charlie England
<ceengland7@gmail.com <mailto:ceengland7@gmail.com>> wrote:
>> Bob,
>>
>> My comment was about 'buttonology'; not building. I've got a little
clock that's RF linked=C3=82 to Federal time broadcasts. It's totally
impossible to use any of the elaborate built-in functions with out the
manual, because it has two or three unmarked buttons, and to access the
various functions, you need to know the "combination". No one can use
the thing without the book in front of them. Same thing for most
kilo-function watches, etc. Even my old Icom A-4 handheld comm is like
that. I seldom use it, so even though I've owned it for over 20 years, I
still don't know how to program frequencies into it. If it had a keypad,
anyone could pick it up and enter '122.75', or '125.25', etc. But since
it doesn't, the unwashed can only hold the up or down button until they
see the freq they want. For me, a perfect example of something
simplified to the point of un-usability.
>
> Understand. The task before us doesn't
> present much of either programming or
> a control task. The trade offs between
> a two-position, spring-loaded switch
> and a single push-button are valid
> options where a the cadence of button
> ops will transition between scan and
> select modes.
>
> I sympathize with your frustration on
> the radio. I've been purchasing some VERY
> capable but cumbersomely programmed UHF
> transceivers and setting them up for our EMS crews
> to monitor the local hospital repeater.
>
> These radios will do lots of cool stuff
> but you need to learn how to do a hat-dance
> on the controls which consist of 6 push-buttons
> and a knob. Fortunately, I'm only setting
> them up for one frequency and then locking
> the controls. They can be programmed via
> serial cable and a utility that runs under
> Windows . . . I may explore that feature
> in due course. But in the mean time, the
> hat-dance tune for one frequency is simple
> and short.
>
>
> Bob . . .
>
Message 11
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
Eric,
This project was your suggestion, so I'll bow to whatever you want to
do. PIC, no PIC, one switch, two switches - whatever you like! I don't
believe I have a need for this device, so my opinion on the user
interface is irrelevant.
Just for my own "education and recreation", I wrote and tested the PIC
software I described (for a single on-on-(on) switch). It's very
simple, but does what I think you asked. You are welcome to the code if
you are interested.
Alec seems to have a lot more experience that I do, so since he
volunteered, we should let him contribute if you want to go the PIC
route. Either way, it was a fun Sunday afternoon project... especially
since the weather isn't that conducive to flying!
Please let me know if I can be of service. Otherwise, I'll go back into
lurker mode.
Paul Fisher
On 10/14/2017 7:32 PM, Eric Page wrote:
>
>
> nuckolls.bob(at)aeroelect wrote:
>> I propose we make this another open source program like the wig-wag was . .
. I'll be pleased to set up a folder to host all the work product.
>
> Great. I kinda figured we were doing an open-source effort. With that in mind,
I had a good think about this while slogging for six hours against 145-knot
headwinds this morning...
>
> I think there are a few issues that argue against changing to a PIC microcontroller
in this project. Wade alluded to the first one in his post this morning
(which, along with one other from Clayton, has disappeared from the server)
when he joked about the details being over his head:
>
> - It would make the project considerably less accessible to many builders. Anyone
without a hardware programmer and the Microchip IDE software will either
have to get them, then find the code to download and learn how to program the
PIC, or buy a PIC with the code already loaded. On the other hand, anyone pretty
much anywhere with a soldering iron and minimal skill can put my design together
for as long as its jellybean components are available.
>
> - Software updates will require removing the unit from service, removing the
PIC to send for reprogramming, or buying a new PIC to replace it.
>
> - A PIC won't simplify the user interface. We still need a switch for the run/hold/step
function and a knob to adjust scan rate. Perhaps a system using buttons
or a rotary encoder could be devised, but it would probably be less intuitive
than the switch and knob.
>
> - If a PIC could replace the $7 video multiplexer chip, you could make a good
case for lowering cost, but we're talking about replacing a couple of 50 to 80-cent
jellybeans and a few passives that are tens of cents each -- about $3 total.
Can anyone deliver a programmed PIC for $3 and make it worth their trouble?
>
> - The size of the PCB is going to be driven largely by the five RCA jacks, so
deleting a 16-DIP and a few passives probably won't shrink the board appreciably.
>
> I think this is a case where a microcontroller may be overkill, given that suitable
cheap ICs are readily available. Given the simplicity of the problem,
wouldn't it make more sense to keep the solution simple?
>
> Thoughts?
>
> Eric
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=473555#473555
>
>
Message 12
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Subject: | Re: Constructing an automatic RCA video camera feed |
splitter
Well, I drafted a detailed response to all the discussion over the last day or
so, when Windows 10 decided -- without any warning -- to reboot for a security
update. No opportunity to save work, just a sudden blank screen. Absolutely
INFURIATING, and not the first time it's happened.
Anyway, I'll probably miss something, but here's what I covered, as best I can
remember...
1. Alec mentioned the possibility of video glitches or rolling when the feed is
switched from camera to camera, due to the lack of video sync or frame buffering.
If this happens, I will have zero idea how to fix it. I'm what you might
call an ambitious hobbyist, not an engineer. Is this a high-risk thing? I
have no experience here; I just found the mux IC and drew a schematic around
it.
2. Alec also mentioned a Hackaday project to make an A/V switch box...
https://hackaday.com/2007/03/14/diy-av-switch/
That's a neat idea, but I struggle to understand how a digital bus switch IC can
handle an AC video signal when a proper video mux needs pos/neg rails to do
it. It apparently worked, but I don't understand it and comments below the project
suggest that it shouldn't have worked. Again, I'm not an engineer...
3. Some good discussion between Alec and Charlie WRT user interface: buttons,
knobs, switches, etc. My $0.02 is this: if we stay with discrete ICs, the interface
remains a single toggle switch, and either a trimmer or knob/pot for scan
rate. If we use a PIC, I would advocate for a rotary encoder with a dead simple
interface: pushing the encoder switch toggles between scan and hold; when
in scan mode, each click of rotation increments/decrements the pause time on
each camera by 1 sec; when in hold mode, each click of rotation selects the next/previous
camera feed. No user programming, just immediate response to user
input. It would be nice if the PIC could write the selected scan rate to non-volatile
memory each time it's changed, and recall it on power-up.
4. The AD8184 datasheet...
http://www.analog.com/media/en/technical-documentation/data-sheets/AD8184.pdf
...has a section on board layout (pg 7) that suggests a bunch of RF voodoo (striplines,
microstrips, guard rings, termination resistors, etc.) related to preserving
the part's 700MHz bandwidth. According to this Maxim application note...
https://www.maximintegrated.com/en/app-notes/index.mvp/id/750
...a standard definition NTSC video signal occupies 4.2MHz of bandwidth and requires
18MHz of bandwidth for 0.5dB flatness (whatever that means...). So, is
any of the RF voodoo necessary, or will standard PCB traces and copper ground
pours suffice? Short traces will be difficult with RCA jacks, but would be easier
using a D-Sub (see below).
5. Bob made some suggestions:
A. Use a 10-turn potentiometer. I have a 1-turn cermet trimmer in the BoM right
now ($0.79), but it's easily changed to a 10 or 20-turn ($1.43), or to pads
for a remote pot ($0.76) if desired.
B. Design for a D-25 backshell. Good idea, but will the video signals suffer
on a shielded wire -vs- an RCA cable? If not, let's do it. These NorComp parts
are the only ones I can find whose datasheet includes inside dimensions...
https://www.norcomp.net/rohspdfs/BackShells/InternalDimensions/ID-983Series.pdf
...and it doesn't look like I can fit everything into the space in a D-25 shell.
The D-37 shell should have room to spare. Bob, if you have a deep D-25, could
you give me the part number?
C. Use excess pins in the D-Sub as selection jumpers for number of cameras, scan
rate, etc. I presume this would require a PIC pin to read each jumper. Or
perhaps you could use a resistor ladder across multiple D-Sub pins and read the
ladder voltage with a single PIC pin to determine which jumper is installed.
Very good idea for setting number of camera inputs, but I don't see the point
for scan rate; a trimmer (or rotary encoder) seems fine.
D. Use ExpressPCB. I haven't used them for at least 20 years. I don't like their
"walled garden" model or their prices. Their closed software is the antithesis
of "open source," and I'm never in a big enough hurry to justify the expense.
My work will produce standard Gerber files that any board fab can use.
Anyone can order 3 copies of the board from OSH Park...
http://www.oshpark.com/
...for $5/sq inch with free shipping, or upload to any of a half dozen Chinese
fabs...
http://www.pcbshopper.com/
...to get 10 copies of the board in 2-3 weeks for
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=473595#473595
Message 13
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Subject: | Re: Constructing an automatic RCA video camera feed |
splitter
Wade,
We haven't heard from you for awhile. Since you're likely to be the guinea pig
on this project, there are a few items you should have input on:
- Do you have a preference WRT discrete ICs -vs- a PIC microcontroller?
- Do you have any desires for additional features or functions that would push
us in one direction or the other?
- Of the user interface options you've seen discussed, what would be your preference?
- For camera scan rate, would you prefer to set it once and forget it, or have
an accessible control for routine use?
- Would you prefer to install a device with five RCA jacks for signal and a 2-position
header for power, or one D-Sub connector for everything?
Clayton, you expressed interest in getting one of these also; feel free to offer
your opinion on these questions too.
Eric
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=473596#473596
Message 14
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Subject: | Re: Constructing an automatic RCA video camera |
feed splitter
I think the video sync problem could be a big deal. I would absolutely order a
couple of cameras and the screen I intended to use and try switching between the
sources with a mechanical toggle switch to get some confidence the result is
going to be acceptable.
A CD4066 advertises itself as a quad gate analog switch, and its only $0.60. Alternatively
since nobody here (I presume) is an experienced analog video design
engineer, maybe the $8 part is worth it for ease of implementation.
Ive never seen a rotary encoder with a push-button functionality as well. Could
we compromise on a single (on)-off-(on) toggle switch mounted left-right. Click
left or right to go to next or previous camera; Hold left or right for a second
or two to resume scan; Hold left or right for ten seconds to enter/exit speed
change mode.
The PIC programmer in me wants to run and hide from resistor ladder networks for
setting parameters: A 16 pin PIC should have lots of spare pins for jumpers.
If you dont want a speed programming mode there would even be enough pins left
for a speed selector.
> On Oct 15, 2017, at 11:01 PM, Eric Page <edpav8r@yahoo.com> wrote:
>
>
> Well, I drafted a detailed response to all the discussion over the last day or
so, when Windows 10 decided -- without any warning -- to reboot for a security
update. No opportunity to save work, just a sudden blank screen. Absolutely
INFURIATING, and not the first time it's happened.
>
> Anyway, I'll probably miss something, but here's what I covered, as best I can
remember...
>
>
> 1. Alec mentioned the possibility of video glitches or rolling when the feed
is switched from camera to camera, due to the lack of video sync or frame buffering.
If this happens, I will have zero idea how to fix it. I'm what you might
call an ambitious hobbyist, not an engineer. Is this a high-risk thing?
I have no experience here; I just found the mux IC and drew a schematic around
it.
>
>
> 2. Alec also mentioned a Hackaday project to make an A/V switch box...
>
> https://hackaday.com/2007/03/14/diy-av-switch/
>
> That's a neat idea, but I struggle to understand how a digital bus switch IC
can handle an AC video signal when a proper video mux needs pos/neg rails to do
it. It apparently worked, but I don't understand it and comments below the
project suggest that it shouldn't have worked. Again, I'm not an engineer...
>
>
> 3. Some good discussion between Alec and Charlie WRT user interface: buttons,
knobs, switches, etc. My $0.02 is this: if we stay with discrete ICs, the interface
remains a single toggle switch, and either a trimmer or knob/pot for
scan rate. If we use a PIC, I would advocate for a rotary encoder with a dead
simple interface: pushing the encoder switch toggles between scan and hold; when
in scan mode, each click of rotation increments/decrements the pause time
on each camera by 1 sec; when in hold mode, each click of rotation selects the
next/previous camera feed. No user programming, just immediate response to user
input. It would be nice if the PIC could write the selected scan rate to
non-volatile memory each time it's changed, and recall it on power-up.
>
>
> 4. The AD8184 datasheet...
>
> http://www.analog.com/media/en/technical-documentation/data-sheets/AD8184.pdf
>
> ...has a section on board layout (pg 7) that suggests a bunch of RF voodoo (striplines,
microstrips, guard rings, termination resistors, etc.) related to preserving
the part's 700MHz bandwidth. According to this Maxim application note...
>
> https://www.maximintegrated.com/en/app-notes/index.mvp/id/750
>
> ...a standard definition NTSC video signal occupies 4.2MHz of bandwidth and requires
18MHz of bandwidth for 0.5dB flatness (whatever that means...). So, is
any of the RF voodoo necessary, or will standard PCB traces and copper ground
pours suffice? Short traces will be difficult with RCA jacks, but would be easier
using a D-Sub (see below).
>
>
> 5. Bob made some suggestions:
>
> A. Use a 10-turn potentiometer. I have a 1-turn cermet trimmer in the BoM right
now ($0.79), but it's easily changed to a 10 or 20-turn ($1.43), or to pads
for a remote pot ($0.76) if desired.
>
> B. Design for a D-25 backshell. Good idea, but will the video signals suffer
on a shielded wire -vs- an RCA cable? If not, let's do it. These NorComp parts
are the only ones I can find whose datasheet includes inside dimensions...
>
> https://www.norcomp.net/rohspdfs/BackShells/InternalDimensions/ID-983Series.pdf
>
> ...and it doesn't look like I can fit everything into the space in a D-25 shell.
The D-37 shell should have room to spare. Bob, if you have a deep D-25,
could you give me the part number?
>
> C. Use excess pins in the D-Sub as selection jumpers for number of cameras,
scan rate, etc. I presume this would require a PIC pin to read each jumper.
Or perhaps you could use a resistor ladder across multiple D-Sub pins and read
the ladder voltage with a single PIC pin to determine which jumper is installed.
Very good idea for setting number of camera inputs, but I don't see the point
for scan rate; a trimmer (or rotary encoder) seems fine.
>
> D. Use ExpressPCB. I haven't used them for at least 20 years. I don't like
their "walled garden" model or their prices. Their closed software is the antithesis
of "open source," and I'm never in a big enough hurry to justify the
expense. My work will produce standard Gerber files that any board fab can use.
Anyone can order 3 copies of the board from OSH Park...
>
> http://www.oshpark.com/
>
> ...for $5/sq inch with free shipping, or upload to any of a half dozen Chinese
fabs...
>
> http://www.pcbshopper.com/
>
> ...to get 10 copies of the board in 2-3 weeks for
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=473595#473595
>
>
>
>
>
>
>
>
>
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