12-volt matrix input->output?

Yep, keep it simple :-)

BTW we just brought a couple back from church and his name is the same as yours. He is a retired mineral engineer. I told him and he said that he never met another person with that name. At least not in the last nine decades or so and this guy has been all over the world.

overkill... smaller relays are sufficient

+---------- W output | .-------------------|------. NC | NC | NC / | / | / / | / | / 12v---A1 | 12v---B1 '---C1 | NO---| NO----+----------NO | | | | | | NC | | / | | / | `------C2 | | NO---> X output | | | NC--------------NC | / / | / / +-------B2 .-C3 | NO---+----|----NO | | | `--------> Y output | | | | | `---------------> Z output

/|\ /|\ /|\ | | | A-contacts B-contacts C-contacts

A-----. B-----. C-----. | | | ___|___ ___|___ ___|___ | | | | | | | CoilA | | CoilB | | CoilC | |_______| |_______| |_______| | | | 0v----+---------------+---------------+

I guessed it could be simplified but was too lazy to try it. Nice try, but could you check your ascii diagram for typos, there seems to be something wrong.

eg, Look at the req'd '010' input, '1000' output.

The B-relay is closed, connecting B1-NO and B2-NO. This does not produce a 1 on the W output?

There are other anomolies. Contact C3 shorts Y and Z together, but look at the '101' input, this requires Y and Z to be different.

There's a typo or I'm not reading your circuit correctly.

OOPS! you're right

The circuit I posted was incorrect. here's a corrected version.

.------------. .------> W output | | | | .--|--|------. | NC | | | NC | / | | | / | / | | | / 12v-+--B1 | | '---C1 | | NO--+ `---------NO | | | | NC | / | / `---------C2 NO---> X output .------------------.   | | NC | NC-----|--------NC / | / | / / | / | / 12v--A1 +-------B2 | .-C3 | | | NO---' NO--. `--|-----NO | | | `--------> Y output | `--------------> Z output /|\ /|\ /|\ | | | A-contacts B-contacts C-contacts A-----. B-----. C-----. | | | ___|___ ___|___ ___|___ | | | | | | | CoilA | | CoilB | | CoilC | |_______| |_______| |_______| | | | 0v----+---------------+---------------+

[snip rest]

That looks like a goer. Well done, nice bit of simplification. Maybe use 4-off 2PCO relays, (2 in // to get the 3x C-contacts), in chassis-mount sockets. Add 3x flyback diodes across the coils. Just wiring, no soldering, no pcb.

On a sunny day (Wed, 28 Feb 2007 15:12:30 +0000 (GMT)) it happened Tony Williams wrote in :

One company where I worked would have sold the OP a PLC :-)

:)

Someone around here, (and I shall remain anonymous), did actually implement a 4-line to 12-line decoder in a PIC. PIC, RC-clock, 12 output transistors, 12 base resistors, all on a small daughter board that plugged into the original 4-line to 16-line IC socket. One of those desperately desperate retrofit mods to get him out of the brown stuff. :)

Tony Williams sez:

OP request a non-PIC solution.

Thanks,

On a sunny day (Fri, 02 Mar 2007 21:08:22 GMT) it happened Rich Grise wrote in :

Na, if you publish the code (I once did) then they also want a free programmer.

Jan Panteltje sez:

Please don't let a few "can't do it"s keep you from putting up a creative PIC code solution. There's many of us who would delve into the magic PIC world if a programming solution was offered that was tempting enough.

Some day...

Can I suggest:

It comes with a huge set of tutorial examples, starting from the extremely simple. Each example fully works but is meant to be modified, so that you learn by making small changes and proving that they work - rather than try to get a whole program right from scratch.

I've recommended it to a few people that had never written a line of code before - and every one got on well with it.

The final examples are *demanding* - highly advanced techniques that really take some understanding, so it is a good kit for someone who can manage simple stuff, but wants to get to grips with more of the features that PICs provide.

My latest little PIC project controls my central heating, hot water and heat exchangers. It sits on my LAN, so I can monitor and control everything from anywhere - even the office. Even your office.

So, use the 18F or 24 series. There's not much spam^H^H^H^H bank switching in it/them.

Best regards, Spehro Pefhany

Rich Grise sez:

What's your flavor of evil? What PIC-competitor do you favor?

Palindrome sez:

*That* I want to see (code, interface, all). I'd learn to program with awl on stainless steel if I could do create project like that as my first (c: ...

That sort of code is the last thing that I would show someone seriously thinking of learning. It would be like presenting someone who wanted to understand engine design with an F1 racing car engine. Better to start with a one cylinder gas engine.

"Education is a process of diminishing deception", springs to mind.

I would suggest that the secret of picking up a programming language is to take very small steps, with the current program always understood and working before moving on to the next. There is nothing more demoralising than taking a "Giant Leap" - only to end up not having a clue as to where you have landed and why..

Palindrome sez:

I'd look on your project like an art student looks on the Mona Lisa; as something representing the penultimate of the art, something to aspire to.

Come on! Show-n-tell time...

"Education is a process of diminishing *self*-deception"? (c:

Actually, this is kind of a two-sided question. If by "your flavor of evil" you mean "what do you, personally, deem to be 'evil' and why?", I'd say, I deem bank-switching to be evil because it encourages incomprehensible, unstructured, haphazard code that's just a bug looking for a time to happen.

My response is, well even the 8051, piece of crap that it is, is less worse.

My first choice would have to be either one of the FPGA/CPLD houses, whose products don't constrain you very much at all, or, yes, Motorola, who now goes by Freescale, or so I've heard. The nicest micro I've ever had the pleasure to program from scratch so far has been the

68HC11, which, presumably because it was so sophicasted and classy, seems to have died on the vine, preumbably because they were too expensive. )-;

If you mean "What kind of evil do you prefer?", my personal preference of what's "evil" would be those power-trippers who are routinely raping our Constitution of the United States of America. My cure, of course, as directed in the Declaration of Independence, would be to take down the usurpers of the Constitution of the United States of America, and see to it that they get what they deserve, which is life behind bars, or at the end of a rope.

Freedom is my Worship Word. The only Bible I need is The Declaration of Independence and the Constitution of the United States.

And in keeping with my doctrine of Freedom, you are certainly more than welcome to do as you choose as far as PICs and 555s and bank switching, or whatever you want. Which might sound weird to those of you whose mind is only big enough to grasp one concept at a time. ;-)

"Imagine! He can not like something, but it's still OK for other people to do it? Incomprehensible!!!!!" -- any roob

Thanks! Rich

That's another thing about PICcies - they always say, "Use a PIC", without ever saying "THIS IS HOW you 'use a pic'" or providing any kind of docs.

I say, anybody who says "use a pic", without providing "HOW" or "WHY" to "use a pic" (e.g., how is it cheaper than an astable multivibrator, which is done THIS way) should be deemed a troll.

And, for that matter, "use a 555" fits into the same category. It's as if I, who have 20 years' experience slapping together astable multivibrators, were to say, "Use an astable multivibrator" to some newbie (which each and every single one of us [and the married ones too, ] was at one time) who hasn't even heard the term "astable multivibrator".

Bottom line, I deem myself much too classy to pull that kind of stunt. ;-)

Thanks, Rich

Erm, can point out anywhere in this thread that I have proposed using a PIC for this project, or indeed anything electronic?

I wrote purely in response to a self-confessed PIC Virgin, who seemed to want to develop skills in using them. I wrote purely about the learning process.

It is extremely unlikely that a PIC will be the most appropriate solution for a one-off project being undertaken by someone who has never used one. It's much the same as suggesting that a "welding virgin" welds two bits of aluminium together, when a pop rivet will do.

However, just as spending a bit of time learning to weld aluminium can come useful in project after project after project, spending the time learning to program PICs can pay off, if you have project after project after project to complete.

I notice that, in another thread, when I suggested the poster considered using a portable generator instead of an inverter + batteries, you didn't complain about me not describing in detail how to spec the generator. Yet you seem to think that a PIC solution can't be suggested without that level of detail included...

There is an advantage to mentioning the possibility of using a PIC in a thread - even when the OP clearly hasn't got the necessary skills. I am sure that the OP, and other readers unfamiliar with PICs, will see the number of times that they are suggested and get to maybe start thinking that they are missing out and it might be worth spending a bit of time adding them to their skill set.

BTW, it is extremely easy to give you an example of where a PIC will be cheaper than using a standard astable. A PIC "astable" circuit board can be reprogrammed in situ to change parameter over a huge range - with no change in physical components. Or the same board can be reprogrammed to an entirely different functionality, with no change in physical components. Rather than develop and stock a large number of boards for different applications, you just develop one, stock one and just program it for the application, when it is put into use.