[AVR] Little help here building Led Sign Board

[codename25]

Hi,
Can any one please tell me the maximum distance maintained between LEDs in order to get a decent display of letters on led sign board. Also what type of led should be used and it's voltage, current etc.

Thank you.

 

[kam1787]

at what viewing distance
under what conditions - night, daytime,...
dimensions of board?
what color?

 

[codename25]

Thanks for the reply. Maximum viewing distance should me 10-15meters. Both day and night time. Colour is red. The dimension is around 120X12cm.

 

[BradtheRad]

The dimension is around 120X12cm.

Seen from 15 meters away, this should be large enough to display a word.

As for how close to place 2 led's...

I think 1.5 cm's is suitable. Seen from 15 meters away, the normal eye can just about distinguish them as separate. In optical terminology, the led's are at an angular separation of 3 or 4 minutes.

This gives room for you to place 8 led's vertically, enough to form legible characters.

If the led's are too dim for daytime viewing, then you will need to use more of them, and space them closer together.

 

[codename25]

Thanks for the reply, I'm planning to place 10 LEDs vertically. What should be the distance between the LEDs if the viewing distance is 6-8 metres?

 

[BradtheRad]

8m viewing distance is close enough for your sign to have 2 lines of text.

The led's can be 6 or 7 mm apart. That's about when they start to run together.