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These are some brief notes about a 'Countdown clock' I built 10 years ago for Y2K, The clock is 4 feet square from the front. It is about 4 inches thick, and runs on an embedded microcontroller. Each Segment is made from around 20x 10mm LEDS.
I can't take a picture with it on, because it is WAAAY too bright !
The panel was carved from a template I made for an ordinary router, with an extended template following cutter. I made the template in hardboard (fibre board US-ian ?) and just carefully aligned it with marks on the panel to cut it out.
Laying out the second Leds was more of a bitch than I expected - do the math carefully to pitch them PERFECTLY.
I can't take a picture with it on, because it is WAAAY too bright !
The panel was carved from a template I made for an ordinary router, with an extended template following cutter. I made the template in hardboard (fibre board US-ian ?) and just carefully aligned it with marks on the panel to cut it out.
Laying out the second Leds was more of a bitch than I expected - do the math carefully to pitch them PERFECTLY.
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Here's a view of the back of a segment. I used the classic LM317 constant current circuit to drive each bank of LEDs.
The drivers for the displays are done with serial-to-parallel converters which seem to have been replaced with these things:
http://www.allegromicro.com/en/Products/Part_Numbers/6275/index.asp
...these new parts will do all I did then with the 317 as well - a complete LED driver in one chip. Only a single resistor sets the brightness for all the leds !
Each digit is driven by that chained ribbon cable, which carries all the common signals for these chips, Vcc, GND Clock, Latch Enable and output enable. So there are only 6 wires leave the computer for ALL the segments of ALL the characters AND the 60 second LEDS round the edge. Each drive chip though has one unique line( the pink wire) that daisy chains through the whole system. The display looks like a very long shift register - see diagram below
An update for the display takes a very tiny fraction of a second.
The drivers for the displays are done with serial-to-parallel converters which seem to have been replaced with these things:
http://www.allegromicro.com/en/Products/Part_Numbers/6275/index.asp
...these new parts will do all I did then with the 317 as well - a complete LED driver in one chip. Only a single resistor sets the brightness for all the leds !
Each digit is driven by that chained ribbon cable, which carries all the common signals for these chips, Vcc, GND Clock, Latch Enable and output enable. So there are only 6 wires leave the computer for ALL the segments of ALL the characters AND the 60 second LEDS round the edge. Each drive chip though has one unique line( the pink wire) that daisy chains through the whole system. The display looks like a very long shift register - see diagram below
An update for the display takes a very tiny fraction of a second.
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If you did or if you can make a diagram and or a video with the up to date way could you please email it to me through this site that would be awsome for me.
This I really would like to make.
Thank you
Steve
Do you have an email address? Long lost pal of Sharp Shooter , remember?
I would like to put one together with the days,hours ,minutes, seconds and tenths 0f a second if that is the next in line, I am very tired right now I can't think straight right now so I hope you can under stand what im wanting to put together. I you have and questions please feel free to just ask anything
you want.
I am in the process of trying to put together the computer in a tool case. I have almost everything I need to do it so im trying it to see if I really can do it or not. This is my first time doing anything like this and if I can do this project it will boost me up so much and help me really help me get into this more and I will fell better about myself to try the clock that you have. I would really like that to be my neat project after this computer.
If you don't mind I may need some help when I get to loading the BIOS so I might be hollaing at ya for a bit if you don't mind. and if you do mind thats ok to.
Thank you for all you help and please send me the files or video when you get it done. I really want to get into LEDs so I think that one will be a fun project.
Thanks again and I hope to here from you again soon.
DD
Steve