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Constructing an automatic RCA video camera feed splitter

 
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alec(at)alecmyers.com
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PostPosted: Sun Oct 15, 2017 11:34 am    Post subject: Constructing an automatic RCA video camera feed splitter Reply with quote
One of the difficulties of a project like this is that there’s no clear design priority for those who’d like to contribute.
I’ve designed and built a *lot* of hobby PIC projects (the first in 1996, I think) and sold a few too. I’ve 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 “ownership”, adjustability-with-a-hot-soldering-iron are all more important.

Quote:
On Oct 15, 2017, at 3:19 PM, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:
At 12:26 PM 10/15/2017, you wrote:
Quote:
Ditto Charlie! do not archive On Sun, Oct 15, 2017 at 8:50 AM, Charlie England <ceengland7(at)gmail.com (ceengland7(at)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.
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 . . .



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alec(at)alecmyers.com
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PostPosted: Tue Oct 17, 2017 5:50 pm    Post subject: Constructing an automatic RCA video camera feed splitter Reply with quote
In the fantasy world I enjoy inhabiting, where I’ll happily spend four days of engineering resource researching a different chip to save $0.50 in parts costs (which really only makes sense when you anticipate a production run of thousands, and let’s be honest how many people are going to build a video switcher?) it’s nice to know that you, Bob, don’t need to commit to programming 10,000 PICs - there exists another option, even if it won’t ever be needed.
Quote:
On Oct 17, 2017, at 9:32 PM, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:
At 04:45 PM 10/17/2017, you wrote:
Quote:
--> AeroElectric-List message posted by: Alec Myers <alec(at)alecmyers.com (alec(at)alecmyers.com)> I just checked on the microchipdirect.com website. If you want Microchip to send you pre-programmed parts, there’s a set-up fee of $29, and a minimum order value of $60. The parts are reasonably priced and the extra cost to program each chip is between USD$0.10 and USD$0.15 for the range of chips we’ve been looking at.
Programming a PIC is just slightly more than a trivial task. You need a PIC KIT 3 programmer . . http://tinyurl.com/ya66phql which comes with the development/programming software. If your project is fitted with ICSP header, the cable supplied with the PIC KIT drops right onto that header. If you wish to program loose chips then you need universal chip to ICSP adapter . . . http://tinyurl.com/y7xt6am5 If one wishes to program SOIC chips before installation, adapters are avaiable to facilitate this task . . . http://tinyurl.com/yazkcare should deliberations on this project arrive at some functional consensus in hardware and performance, I'd be pleased to host the data package defining the project. I'll also offer to program DIP or SMD chips at no charge beyond postage required to return the chip(s).
Bob . . .



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