Hi q
Hi,
I want to control a matrix panel 32x64 within 2048 leds.
for this project i' ve planned to use some 16 line demultiplexer(2 mux rows and 4 mux columns), I suppose to select each led and turn on it with quick refresh.
I've seen max2219 but if possible i want to use ttl demulitiplexer 74154, it's so easy to use and much cheap.
can I write digital output in one shot?
I don't want to get into this too much, because I don't think you're on the right track.
A MAX7219 does a lot more than simply multiplex a few outputs.
I'm not sure your concept with the 74154 will even work. Do you have some sort of schematic for a small 4x4 Matrix that you intend to build?
I agree that the 7219 is not very cheap, but it will be definitly much easier to use than your own setup software- and hardware-wise .
Your code switches the test-Led on for only 2 ms per second. This is way too short.
A MAX7219 guarantees that every lit Led is on for 125ms per second. I think you have to get near that value to make your concept work.
Think about the 7219 again, in the end its going to be the cheaper solution.
Eberhard