Need explanation

[tishri]

hello guys,

i need help. can you please give me just a slight idea how scrolling led works?

why do we need decade counters? whats the concept behind why characters are being displayed? thanks

[Bruce]

i need help. can you please give me just a slight idea how scrolling led works?
Individual LEDs or LED displays?


why do we need decade counters?
1. People can't count that high without removing their shoes.
2. Folks are too busy to count for 10 years, so they hire a decade counter.
3. It's an easy job for old cousin Earl with nothing better to do for the next 10 years.
4. Electronic counters.

Just kidding...;o}

Here's a few examples;
http://www.doctronics.co.uk/4017.htm
http://www.hobbyprojects.com/digital_circuits/7490_decade_counter.html


whats the concept behind why characters are being displayed
What type of display are you refering to?

[tishri]

im just confused how this works. how come that all rows to be displayed are connected to the last column of the led matrix display. :) thanks

[skimask]

im just confused how this works. how come that all rows to be displayed are connected to the last column of the led matrix display. :) thanks

Because in most matrix displays (if this is the type we're talking about), you are only lighting up one row at a time...just like a CRT display. You don't/can't light up the whole screen at once, you scan the CRT, one line at a time, until the whole screen is scanned (the persistence of the phosphor 'holds' the picture), then you start over and scan the whole thing again.

If you do it fast enough, your eyes don't know the difference and you don't need nearly as many lines (and nearly as much hardware) to drive a display as you would if you tried to light every LED individually all at the same time.

[tishri]

thank you for the information