ROBOT.LK

Circuit diagram for a moving LED matrix display.

Shane wrote:Circuit diagram for a moving LED matrix display.

text_scroller.jpg

Can I use this for a large matrix display (like 16*64) ?
Will it show good outputs?

Think about it as this. You TV refreshes the display 25 times per second. With two fields, it is like 50 fields per second.
With a microcontroller, How fast you think you can refresh these LED displays ? That's how this scanning method work. Though it can be logically thought as drawing to one display at a time, due its speed, no one will notice that. This is the common method used. Good luck and keep us updated.

Shane wrote:Think about it as this. You TV refreshes the display 25 times per second. With two fields, it is like 50 fields per second.
With a microcontroller, How fast you think you can refresh these LED displays ? That's how this scanning method work. Though it can be logically thought as drawing to one display at a time, due its speed, no one will notice that. This is the common method used. Good luck and keep us updated.

Thank you, I'll try to see it practically.

Writing firmware for this.....
If you can understand the basic operation of a latch and shift register, it is easy to write the firmware by yourself. 74HC259 is a latch and 74HC595 is a shift register. If you want to become a good electronic engineer, it is a must to learn how to read a datasheet carefully and understand.

Here are the datasheets.
http://www.nxp.com/documents/data_sheet/74HC_HCT259.pdf
http://www.nxp.com/documents/data_sheet/74HC_HCT595.pdf

74HC595 datasheet is not clear to beginners. arduino.cc/en/Tutorial/ShiftOut helps me to understand it.
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