LED Matrix design issues

Hello,

My only requirement to create LED rolling display is "cost effective".

I have got 256 LEDs, 12V, 2A supply, 74HC373, ULN2003 and 89V51RD2BN to design a LED matrix and a control ckt.

I think 16x16LED matrix would serve purpose with 2 ICs 74HC373 on Rows and 2 on columns all controlled by 89V51. ULN will not be used.

But, will 12V, 2A supply be sufficient for it? Also, can I drive 4 ics 74HC373 using a 89v51? I also have to use UART for programming and few pins for memory interface.

Please let me know, if I am thinking in right direction :idea:. Also, if anyone can suggest better design...he is welcome

The power requirement depends on the type of the led's you are using.

Most possibly the supply you have is enough for that.

Use a better powersupply, say 12v 5A for testing and measure the current at required brightness of the led's.

The LEDs I am using are 3mm LEDs which are locally available in mkt. As per my understanding, 20mA would be enough for all LEDs in series. That is why I though 2A would be enough. But, I missed the voltage rating

So, now dilemma is, which combination of Rows x Columns to use ??

do you want to use scan techniqe or not

Medtronic said:

do you want to use scan techniqe or not

Click to expand...

I am not sure, what is scanning technique but I guess, you are saying if I want to use Rows x Columns technique just like keypad matrix.
Yes...as I have to display letters and numbers onto it, scanning technique would be the only solution.