AVR-Chat

Hi all,

I am in need of a circuit that can detect mating to another part.

Think door lock and keys, or party  favors... ??

It would be that one part would be connected to another of about 40 
possible combinatoins, and only if it is correct would the thing 
work.  say, light an LED or something.

I'm thinking when the two parts meet, they both light an LED to 
indicate the correct two were connected.

I am looking for someone who can lay out the curcuit, schematic, 
program the micro test it.

The probably power will a cell phone (or similar) battery.

And, no, I do not expect it will be free.

I can make my own PCB's, but if you need to that is fine.

any takers ?

I have some additional details, but that is the basic project.

if, you can't get my e-mail from yahoo, try  

dave_mucha  at  yahoo  dot com

Dave

On Fri, 18 Feb 2005 16:49:29 -0000, Dave Mucha <dave_mucha@yahoo.com>  
wrote:

>
> It would be that one part would be connected to another of about 40
> possible combinatoins, and only if it is correct would the thing
> work.  say, light an LED or something.
> I'm thinking when the two parts meet, they both light an LED to
> indicate the correct two were connected.


In exactly which form do they "mate"? ;-)
Do they have contacts or connectors of some sort?

Have you cosidered using DBx connectors and simply wiring different pins?

ST

--- In AVR-Chat@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
> On Fri, 18 Feb 2005 16:49:29 -0000, Dave Mucha <dave_mucha@y...>  
> wrote:
> 
> >
> > It would be that one part would be connected to another of about 
40
> > possible combinatoins, and only if it is correct would the thing
> > work.  say, light an LED or something.
> > I'm thinking when the two parts meet, they both light an LED to
> > indicate the correct two were connected.
> 
> 
> In exactly which form do they "mate"? ;-)
> Do they have contacts or connectors of some sort?
> 
> Have you cosidered using DBx connectors and simply wiring different 
pins?
> 
> ST

The mating would be by being next to each other.  maybe a contact 
type connection, but not plugs or any type of protruding contacts.

Think of a deck of cards that would be flat and need to touch to be 
identified.  (really close is fine)   alignement is fine if an opto 
sensor were to be used.  ie: serial handshaking.    RF is not desired.

Dave

On Fri, 18 Feb 2005 18:14:31 -0000, Dave Mucha <dave_mucha@yahoo.com>  
wrote:

>
> The mating would be by being next to each other.  maybe a contact
> type connection, but not plugs or any type of protruding contacts.
> Think of a deck of cards that would be flat and need to touch to be
> identified.  (really close is fine)   alignement is fine if an opto
> sensor were to be used.  ie: serial handshaking.    RF is not desired.
> Dave


I suggest either using IR or using inductive transmission (coils).
Do the devices have batteries?
Are there "male" and "female" devices, or can they mate freely?
(in other words are some TX and some RX or are they all TX/RX)

ST

--- In AVR-Chat@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
> On Fri, 18 Feb 2005 18:14:31 -0000, Dave Mucha <dave_mucha@y...>  
> wrote:
> 
> >
> > The mating would be by being next to each other.  maybe a contact
> > type connection, but not plugs or any type of protruding contacts.
> > Think of a deck of cards that would be flat and need to touch to 
be
> > identified.  (really close is fine)   alignement is fine if an 
opto
> > sensor were to be used.  ie: serial handshaking.    RF is not 
desired.
> > Dave
> 
> 
> I suggest either using IR or using inductive transmission (coils).
> Do the devices have batteries?
> Are there "male" and "female" devices, or can they mate freely?
> (in other words are some TX and some RX or are they all TX/RX)
> 
> ST

IR would be fine, prefer to have extreemly close and not something 
that would work more than an inch apart.

And, yes, each unit will have a battery.  Most likely a flat cell 
phone batt or similar

Dave

--- In AVR-Chat@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
> On Fri, 18 Feb 2005 19:26:17 -0000, Dave Mucha <dave_mucha@y...>  
> wrote:
> 
> >
> > IR would be fine, prefer to have extreemly close and not something
> > that would work more than an inch apart.
> > And, yes, each unit will have a battery.  Most likely a flat cell
> > phone batt or similar
> > Dave
> 
> 
> I think coils would be better then.
> My guts tell me it is easier to make it only work on close 
distances with  
> coils. Light doesn't work well that way i fear, in air.
> 
> Can you guarantee some sort of alignment, like, imagining the pack 
of  
> cards, that it would always lie flat and never stand on-edge? The 
RFID  
> systems seems to have big problems with alignment, so if you were 
to use  
> field strength as distance indicator you'd need to guarantee some  
> alignment. I think the coupling between two flat coils could be 
used well,  
> know the inductive-recharge contactless toothbrushes?
> 
> Sound might be another option, but can be disturbed by noise, 
depends on  
> what you are doing.
> 
> Electric contacts seem only reasonable if you can ensure 
positioning etc.
> 
> 
> ST

yes,  postioning and alignment can be guaranteed.  One option is to 
align them with dimples and to connect them with magnets.

Dave

On Fri, 18 Feb 2005 19:26:17 -0000, Dave Mucha <dave_mucha@yahoo.com>  
wrote:

>
> IR would be fine, prefer to have extreemly close and not something
> that would work more than an inch apart.
> And, yes, each unit will have a battery.  Most likely a flat cell
> phone batt or similar
> Dave


I think coils would be better then.
My guts tell me it is easier to make it only work on close distances with  
coils. Light doesn't work well that way i fear, in air.

Can you guarantee some sort of alignment, like, imagining the pack of  
cards, that it would always lie flat and never stand on-edge? The RFID  
systems seems to have big problems with alignment, so if you were to use  
field strength as distance indicator you'd need to guarantee some  
alignment. I think the coupling between two flat coils could be used well,  
know the inductive-recharge contactless toothbrushes?

Sound might be another option, but can be disturbed by noise, depends on  
what you are doing.

Electric contacts seem only reasonable if you can ensure positioning etc.


ST

On Fri, 18 Feb 2005 20:28:29 -0000, Dave Mucha <dave_mucha@yahoo.com>  
wrote:

>
> yes,  postioning and alignment can be guaranteed.  One option is to
> align them with dimples and to connect them with magnets.
> Dave

:-))) i can imagine something really nice with small neo magnets.
place 2 in each device, one north down and one south down, and let the  
alignment magic commence ;-)

Ok, this way optical would be easily possible, and even electric contacts,  
but i dunno if contacts are the better idea (dirt and stuff). Put in some  
tiny atmel and let it send a serial code which the other device  
recognizes, and you are done.

Now why do you want someone to do that for you? you can easily do it  
yourself.

ST

>
>I am looking for someone who can lay out the curcuit, schematic,
>program the micro test it.

Well, that's the sort of thing I do..
I've watched the emails, but I'm just getting back up to speed.

Sounds like you're not married to a particular technology, but the 
requirements are pretty vague.

Should we talk privately under an NDA?

How about magnets on one side and reed switches or halleffect sensors 
on the other side?

JoeT




--- In AVR-Chat@yahoogroups.com, "Dave Mucha" <dave_mucha@y...> wrote:
> 
> --- In AVR-Chat@yahoogroups.com, "Stefan Trethan" 
> <stefan_trethan@g...> wrote:
> > On Fri, 18 Feb 2005 16:49:29 -0000, Dave Mucha <dave_mucha@y...>  
> > wrote:
> > 
> > >
> > > It would be that one part would be connected to another of 
about 
> 40
> > > possible combinatoins, and only if it is correct would the thing
> > > work.  say, light an LED or something.
> > > I'm thinking when the two parts meet, they both light an LED to
> > > indicate the correct two were connected.
> > 
> > 
> > In exactly which form do they "mate"? ;-)
> > Do they have contacts or connectors of some sort?
> > 
> > Have you cosidered using DBx connectors and simply wiring 
different 
> pins?
> > 
> > ST
> 
> The mating would be by being next to each other.  maybe a contact 
> type connection, but not plugs or any type of protruding contacts.
> 
> Think of a deck of cards that would be flat and need to touch to be 
> identified.  (really close is fine)   alignement is fine if an opto 
> sensor were to be used.  ie: serial handshaking.    RF is not 
desired.
> 
> Dave