LED display segment flashing sequence - Electronic Circuits Projects Diagrams Free

john1 · 29th January 2007, 11:44 PM

Hi,

I'm trying to find out a bit about those little led displays which
flash around the characters quite quickly, the type i'm thinking of
are usually clock or watch displays, they flash the segments in
rotation to form the number display.

I think they do it like that to get it brighter, cos if they just
light the segments to make the numbers its not so bright for some
reason.

I want to find out the order that they flash the segments.
Or anything about the way they flash the segments.

John

RODALCO · 30th January 2007, 12:57 AM

Do you mean multiplexing the display ?

john1 · 30th January 2007, 01:01 AM

Yes, i suppose it is multiplexing ....

Do they just light one segment of the display at a time ... ?

Sceadwian · 30th January 2007, 01:19 AM

Multiplexing isn't done to control brightness it's done to decrease the number of I/O pins required to control a large number of LED/LCD segments. Look up Multiplexing and CharliePlexing on Wikipedia.

john1 · 30th January 2007, 01:22 AM

Ok, will do.

John

john1 · 30th January 2007, 01:43 AM

I had a look through the Wikipedia articles on multiplexing and charlieplexing,
they are more of a sort of overview of the principles than anything specific.

I am inclined to think that the multiplexing set-up for the four characters of
a 24HR display would probably be across all the segments involved, rather
than for each character.

If i can get the MX frequency down nice and low, i may be able to see it
clock around all the segments one after the other.

I'll see how i get on,
Cheers, John

Sceadwian · 30th January 2007, 03:07 AM

You can use a digital camera at different shutter speeds, just take a LOT of pictures, you should be able to put together the sequence yourself, as long as the switching rate isn't too high.

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29th January 2007, 11:44 PM	#1
john1	LED display segment flashing sequence Hi, I'm trying to find out a bit about those little led displays which flash around the characters quite quickly, the type i'm thinking of are usually clock or watch displays, they flash the segments in rotation to form the number display. I think they do it like that to get it brighter, cos if they just light the segments to make the numbers its not so bright for some reason. I want to find out the order that they flash the segments. Or anything about the way they flash the segments. John __________________ ************************************************ *************

30th January 2007, 12:57 AM	#2
RODALCO	Multiplexing Do you mean multiplexing the display ? __________________ There are more ways to get to Rome. Electricity, Electric clocks, Meters and Trains are great. Please don't sent me private messages, I will not answer them. The questions asked can be discussed in the open forums. http://www.youtube.com/user/RODALCO2007 some interesting electrical stuff to watch.

30th January 2007, 01:01 AM	#3
john1	Yes, i suppose it is multiplexing .... Do they just light one segment of the display at a time ... ? __________________ ************************************************ *************

30th January 2007, 01:19 AM	#4
Sceadwian	Multiplexing isn't done to control brightness it's done to decrease the number of I/O pins required to control a large number of LED/LCD segments. Look up Multiplexing and CharliePlexing on Wikipedia. __________________ "Because I be what I be. I would tell you what you want to know if I could, mum, but I be a cat, and no cat anywhere ever gave anyone a straight answer, har har."

30th January 2007, 01:22 AM	#5
john1	Ok, will do. John __________________ ************************************************ *************

30th January 2007, 01:43 AM	#6
john1	I had a look through the Wikipedia articles on multiplexing and charlieplexing, they are more of a sort of overview of the principles than anything specific. I am inclined to think that the multiplexing set-up for the four characters of a 24HR display would probably be across all the segments involved, rather than for each character. If i can get the MX frequency down nice and low, i may be able to see it clock around all the segments one after the other. I'll see how i get on, Cheers, John __________________ ************************************************ *************

30th January 2007, 03:07 AM	#7
Sceadwian	You can use a digital camera at different shutter speeds, just take a LOT of pictures, you should be able to put together the sequence yourself, as long as the switching rate isn't too high. __________________ "Because I be what I be. I would tell you what you want to know if I could, mum, but I be a cat, and no cat anywhere ever gave anyone a straight answer, har har."