Interesting LED clock, how did he do it?
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Posts: 46,084
Recently on Ebay, I happened across a PIC based LED clock, that used
60 LED's arranged in a circle around a old CD Rom disk. (You know
those CD's that fail to burn for one reason or another).
Anyway, I passed on it as the SMT devices were too much trouble for
me to want to deal with.
But it got me to thinking about how he might have controlled the
clock so that the seconds would tick off one at a time. He had 60
LED's with the hour and minute LED's on, and the seconds would tick
around the circle. 60 LED's exceed the 15 to 32 I/O lines we normally
have avalaible. So he muct be using something else in there.
Maybe a few bargraph driver chips?
Any ideas?
60 LED's arranged in a circle around a old CD Rom disk. (You know
those CD's that fail to burn for one reason or another).
Anyway, I passed on it as the SMT devices were too much trouble for
me to want to deal with.
But it got me to thinking about how he might have controlled the
clock so that the seconds would tick off one at a time. He had 60
LED's with the hour and minute LED's on, and the seconds would tick
around the circle. 60 LED's exceed the 15 to 32 I/O lines we normally
have avalaible. So he muct be using something else in there.
Maybe a few bargraph driver chips?
Any ideas?
Comments
additional digital inputs and outputs with shift registers. A
parallel to serial shift register such as the CD4021 can be used
for digital inputs and a serial to parallel part such as the
74HC595 can be used for outputs.
Either of these parts can be cascaded together to allow the
addition of nearly any amount of I/O. The limiting factor is
typically how fast the inputs can be read and the outputs updated
and how much RAM is available to hold the data needed.
The technique used for reading the inputs is generally something
like...
toggle the pin the latches the data into the shift register
for x = 1 to 8
send a clock pulse to the shift register
read the output bit and set the LSB in a byte variable equal to
it
shift the byte variable left one bit
next x
This can be repeated for however many input registers you have in
the chain. The technique requires only three of the
microcontroller or Stamp's I/O lines for the strobe, clock, and
data signals.
Tim
Original Message
From: "earlwb" <earlwbollinger@a...>
> But it got me to thinking about how he might have controlled
the
> clock so that the seconds would tick off one at a time. He had
60
> LED's with the hour and minute LED's on, and the seconds would
tick
> around the circle. 60 LED's exceed the 15 to 32 I/O lines we
normally
> have avalaible. So he muct be using something else in there.
> Maybe a few bargraph driver chips?
> Any ideas?
---
Jeff Abrams
clavier@b...
SUPERCHARGED 2.5 liter 1993 Mazda MX-3 GS
http://www.mazdamaniac.com
TURBOCHARGED 1997 Mazda MX-5 Miata
Anytime I see something screech across a room and latch onto someones
neck, and the guy screams and tries to get it off, I have to laugh, because
what is that thing?
Original Message
From: earlwb [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=e27NT-qrjHsyKuGzB6YrZiUI2SyuPLVI_3ydnLOjPd3bYIJgDVw8DtdPywIl6_dLDA58X9rhaBmtiHUYocnU]earlwbollinger@a...[/url
Sent: Wednesday, December 26, 2001 7:59 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Interesting LED clock, how did he do it?
Recently on Ebay, I happened across a PIC based LED clock, that used
60 LED's arranged in a circle around a old CD Rom disk. (You know
those CD's that fail to burn for one reason or another).
Anyway, I passed on it as the SMT devices were too much trouble for
me to want to deal with.
But it got me to thinking about how he might have controlled the
clock so that the seconds would tick off one at a time. He had 60
LED's with the hour and minute LED's on, and the seconds would tick
around the circle. 60 LED's exceed the 15 to 32 I/O lines we normally
have avalaible. So he muct be using something else in there.
Maybe a few bargraph driver chips?
Any ideas?
that doesn't support the Flash and Java on my site.
It is upgrade time. (º;
Netscape is in version 6 and Internet Explorer is in version 5.5 I think.
If you don't like those you can get Opera...
---
Jeff Abrams
clavier@b...
SUPERCHARGED 2.5 liter 1993 Mazda MX-3 GS
http://www.mazdamaniac.com
TURBOCHARGED 1997 Mazda MX-5 Miata
If a kid asks where rain comes from, I think a cute thing to tell him
is "God is crying." And if he asks why God is crying, another cute thing to
tell him is "Probably because of something you did."
Original Message
From: Peter [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=mfA7fMXiA_yFhK0N6x5JZJU_xgXclAENybstKOCB5_5Xc7tqBmZ73rQLJ_HyJeGTnIDprFazOrQ4]ozoneone@y...[/url
Sent: Wednesday, December 26, 2001 1:44 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Interesting LED clock, how did he do it?
Netscape 4.7.3 message:"This page uses frames, but your browser doesn't
support them."
What's wrong with this page???
>
>
> SUPERCHARGED 2.5 liter 1993 Mazda MX-3 GS
> http://www.mazdamaniac.com
> TURBOCHARGED 1997 Mazda MX-5 Miata
>
>
VF display ) and I have never had a problem.
http://www.allegromicro.com/sf/5833/index.htm
they have a led driver built in with a 32 bit shift reg.
Anthnoy
Peter, Belgium.
Oorspronkelijk bericht
Van: earlwb [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ZyHTPLfFmmg9CNyG24SoF912J4iLeXHjWXvsOG1JhCChEJgV0zf166ZH-_KUI3Q5T0pgspPuD9xZSeO8-eAyidjABA]earlwbollinger@a...[/url
Verzonden: woensdag 26 december 2001 13:59
Aan: basicstamps@yahoogroups.com
Onderwerp: [noparse][[/noparse]basicstamps] Interesting LED clock, how did he do it?
Recently on Ebay, I happened across a PIC based LED clock, that used
60 LED's arranged in a circle around a old CD Rom disk. (You know
those CD's that fail to burn for one reason or another).
Anyway, I passed on it as the SMT devices were too much trouble for
me to want to deal with.
them."
What's wrong with this page???
>
>
> SUPERCHARGED 2.5 liter 1993 Mazda MX-3 GS
> http://www.mazdamaniac.com
> TURBOCHARGED 1997 Mazda MX-5 Miata
>
>
_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com
It consisted of three old CD rom disks. One disk served as the base.
The other two disks conprised the front and back of the clock. 60 leds, were
arranged around in a circle on one CD. With Yellow LEDs used for the hour
marks. The rest of the LEDs were red. A small PC board with surface mount
parts was used with a lot of blue wire wrap wire interconnecting the LEDs. A
little AC powersupply brick supplied power. The back CD Disk covered up the
back with all the wires.
It wasn't a bad arrangement at all.
Maybe whoever was selling them will see these postings.
Original Message
From: Daliti [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=23uXokoaLTPwE_oxrPBVlaovwNU2NOwCLAHgvkkHK_U6Pay6J0NNYsLMAe445EigFnJdHcl7enuI62xZg9yQ9Cej1h8]peter.christiaen@s...[/url
Sent: Wednesday, December 26, 2001 12:20 PM
To: basicstamps@yahoogroups.com
Subject: RE: [noparse][[/noparse]basicstamps] Interesting LED clock, how did he do it?
IS there anywhere a picture available of this clock?
Peter, Belgium.
Oorspronkelijk bericht
Van: earlwb [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=1bkYx7EBZqhmlyXfmZ6_7R85Gys2BpMowyNubA_pk9aweMndtVAfVkTQqJufPvn-f9QmjwtH7Xsz7hbo65MmgYY]earlwbollinger@a...[/url
Verzonden: woensdag 26 december 2001 13:59
Aan: basicstamps@yahoogroups.com
Onderwerp: [noparse][[/noparse]basicstamps] Interesting LED clock, how did he do it?
Recently on Ebay, I happened across a PIC based LED clock, that used
60 LED's arranged in a circle around a old CD Rom disk. (You know
those CD's that fail to burn for one reason or another).
Anyway, I passed on it as the SMT devices were too much trouble for
me to want to deal with.
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aconti@s... writes:
<< You could use two of these. Grate Chips I use the brother chips ( for
VF display ) and I have never had a problem.
http://www.allegromicro.com/sf/5833/index.htm
they have a led driver built in with a 32 bit shift reg.
Anthnoy
>>
Why not divide the 60 LEDs into 4 groups of 15 each and then use 4 pins to
switch each group (anodes) to +5 sequentially and 15 pins to pull (through
limiting resistors) each one to ground when it is time to turn it on? Only
uses 19 pins.
Max
Thanks
Earl
Original Message
From: MaxToole@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Gaqc8xe6TOMPReAmAxhQ118xTlo4o1EvQUltEzYUWfCzaitNwbUQaNSL7rDYBJUKMgc9-kPuuSzi]MaxToole@a...[/url
Sent: Wednesday, December 26, 2001 3:02 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Re: Interesting LED clock, how did he do it?
In a message dated 12/26/2001 11:10:28 AM Eastern Standard Time,
aconti@s... writes:
<< You could use two of these. Grate Chips I use the brother chips ( for
VF display ) and I have never had a problem.
http://www.allegromicro.com/sf/5833/index.htm
they have a led driver built in with a 32 bit shift reg.
Anthnoy
>>
Why not divide the 60 LEDs into 4 groups of 15 each and then use 4 pins to
switch each group (anodes) to +5 sequentially and 15 pins to pull (through
limiting resistors) each one to ground when it is time to turn it on? Only
uses 19 pins.
Max
To UNSUBSCRIBE, just send mail to:
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browser as frame-enabled.
Original Message
> Netscape 4.7.3 message:"This page uses frames, but your browser doesn't
support them."
>
> What's wrong with this page???
Of course Netscape 4.7.3
supports frames!
Thanks, Jeff, but Netscape 6 is a bit too AOL for me. Opera is neat but I got
tired of installing it every month
after it self destructs.
Jeff Abrams wrote:
> Nothing wrong with the page, you are just using an old version of Netscape
> that doesn't support the Flash and Java on my site.
> It is upgrade time. (º;
> Netscape is in version 6 and Internet Explorer is in version 5.5 I think.
> If you don't like those you can get Opera...
>
>
> Rodent wrote:
>
>> Either your browser is really old or the web server is not identifying your
>> browser as frame-enabled.
>
_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com
intentionally ignore features of non-IE browsers.
And actually, they are up to IE6, which is not a bad product.
Original Message
Thank you Rodent, I believe that's what it is, the server's error or
something. Of course Netscape 4.7.3
supports frames!
Thanks, Jeff, but Netscape 6 is a bit too AOL for me. Opera is neat but I
got tired of installing it every month
after it self destructs.
The Nutscrape 5 and lower browsers do not support Java, Flash and DHTML
correctly.
---
Jeff Abrams
clavier@b...
SUPERCHARGED 2.5 liter 1993 Mazda MX-3 GS
http://www.mazdamaniac.com
TURBOCHARGED 1997 Mazda MX-5 Miata
When you die, if you get a choice between going to regular heaven or
pie heaven, choose pie heaven. It might be a trick, but if it's not,
mmmmmmm, boy.
Original Message
From: Rodent [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=f2OxkZctM2RqfN_7hsROMhJ4klNv0D2_E9yi1ciZjYT_p10dEG-ReM_ce44oHzCFMpu4Santyp1viYASrw]daweasel@s...[/url
Sent: Thursday, December 27, 2001 5:37 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Interesting LED clock, how did he do it?
I would suspect they are running a Microsoft web server product, which may
intentionally ignore features of non-IE browsers.
And actually, they are up to IE6, which is not a bad product.
Original Message
Thank you Rodent, I believe that's what it is, the server's error or
something. Of course Netscape 4.7.3
supports frames!
Thanks, Jeff, but Netscape 6 is a bit too AOL for me. Opera is neat but I
got tired of installing it every month
after it self destructs.