How to display running text with p4.75 panel

The Dot Matrix Display (DMD) is a 32x16 array of high-brightness LEDs for visually striking effects. [Product Page]
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Joined:Sun May 20, 2018 9:51 am
How to display running text with p4.75 panel

Post by anhyuma_angga » Sun May 20, 2018 10:11 am

I have used DMD library in my p10 panels program and it works awesome. But now i am using a p4.75 panel and i dont know how about the program. My question is how to program running text with p4.75 panels? Anyone have the libraries? Thx for the answer :)

Joined:Fri Sep 20, 2013 7:25 am

Re: How to display running text with p4.75 panel

Post by Brissieboy » Sun May 20, 2018 10:20 pm

I think you will have trouble with this.
I think these panels are 1/16 scan, not 1/4 scan like the DMD, but I do not have access to full details of these so this is an assumption based on what I have seen. And I am also assuming you are using a single colour display and driving it with an Arduino.
It would not be difficult to modify the DMD library to handle the 1/16 scan, but the there will be a problem with flicker of the display.
The DMD library updates 1/4 of the display each interrupt and does it just often enough so that it is not visible.
Having 1/16 scan will mean that it will take 16 interrupts to update the display instead of 4 which will cause severe flicker.
Furthermore, it would not be possible to increase the interrupt rate sufficient to hide the flicker as you would run out of time for the interrupt to complete before the next one is called.
You may need to reconsider what you use to drive this display.

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