Panel not displaying anything


#21

So the store I bought the panel from are refusing to replace the panel claiming it doesn’t fall under the Consumer Rights Act. I’m going to contact local authorities to see what my options are but if not I’ll probably have to buy a new panel.

I’m wondering if it would be possible to power one of these 64x64 displays using the smartmatrix shield? The listing shows the panel as 1/16 scan so I think it would be supported?


#22

It’s possible that the panel will have a mapping that is currently not supported by the SmartMatrix Library even though it’s 1/16 scan. The mapping must currently look like two 32x64 panels chained together. If the mapping wraps two adjacent rows, that’s currently not supported. I plan to update the library to support 16x32/4 panels and other panels that need this type of mapping, but that will probably be months from now.


#23

I’ve messaged them to see if they have any information about the pinout and how the rows are addressed. Would be really nice to have 4 times the amount of pixels for the same price as the 32x32 panel would be. How does the chaining actually work? Do you just clock in a 128 pixel line rather than a 64 pixel one? I imagine that gets really resource intensive with the full size advertisement billboards.


#24

How does the chaining actually work? Do you just clock in a 128 pixel line rather than a 64 pixel one?

That’s the basics of how it works.

I imagine that gets really resource intensive with the full size advertisement billboards.

64x64 is pushing the limits on the Teensy 3.2. A Raspberry Pi can drive a much larger display


#25

Ah damn. It seems the page is wrong and that display is actually 1/32 scan. May get two of the 32x64 instead though. Still cheaper than buying a 32x32 from my original supplier. I think it would be worth it for double the pixel density really. Two displays like that should work fine with the smartmatrix right? Only issue is the power supply. I’m thinking I may just be able to take power from my PC.


#26

Two displays like that should work fine with the smartmatrix right?

It should work “fine”, but you have to compromise with lower refresh rate and color depth. “64x64 is pushing the limits on the Teensy 3.2”


#27

How far would they need to drop? I’d prefer higher refresh rate and don’t mind if I only get 256 colors as I’d actually prefer more contrast between the pixels.


#28

24-bit color and refresh rate around 90FPS depending on what you’re doing. I notice some flicker when playing GIFs on a 64x64 display, but it’s not horrible.


#29

Really? That seems more than enough. I thought you meant it would only handle 8bit color at 30FPS or something. What sort of performance does it get on a 32x32 panel then?


#30

36-bit color 120Hz refresh is standard, but there’s room to do more with diminishing returns.


#31

Wow that’s impressive. I’d be happy with truecolor at 60fps really. Is 36 bit color actually noticeably better? I thought the only reason we used >24bit color was to preserve data for editing purposes.


#32

60fps refresh on the LED matrix would have significant flicker. I was surprised to learn this when I started working with the panels. It’s not the same as a LCD or CRT monitor. You can notice a difference between 24-bit and 36-bit color when some pixels are at lower brightness.


#33

Just received two 32x64 panels from China and I’m glad to say they work beautifully. Just wish I had time to program them to display something useful. Unfortunately I’m busy producing a mechanical keyboard for my university degree and don’t have time for much else. :frowning:

Thank you for your help!


#34

Had a bit of free time while waiting for PCBs so decided to make a bit of progress on this project. Glad to say I have both displays working together beautifully as a 64x64 panel. Managed to get up to around 50% brightness on the brightness test with a 4 amp supply before it reset so it seems to be adequate for my usage as I definitely don’t need it to run any where near its maximum brightness capabilities. I’ll probably try up it to maybe a 6 amp though just to be safe.