Using 64x64 matrices - vertical mapping

[bidmangler]

I've tried a few different Hub75 controllers - and am really impressed by the performance of the Interstate 75 + ease of programming when compared to, say, running a Raspberry Pi with https://github.com/hzeller/rpi-rgb-led-matrix.

The limiting factor for me though is not being able to vertically map panels to (in my case) create a square 128x128 display from 4 64x64 panels. These panels are much easier to obtain and give me the size of display I'm looking for.

I note that vertical mapping is on the TODO list - but how imminent is that likely to be? If it's within a month or two, I'll stick with the Interstate75 solution!

[helgibbons]

Does DISPLAY_INTERSTATE75_128X128 work? I think the 2x 128x64 panels that we're shipping in our new starter kit might be wired up in the same way as 4x 64x64s?

[bidmangler]

I did try that - and have just given it another go. It's close - but the mapping isn't right and I can't figure out what could be done to fix it.

See the attached photo that shows how I've got the panels hooked up within my 2x2 config.

It's fairly obvious that it seems to be mapping the top half of the display to the bottom and vice-versa - so as I say, close but not right.

[helgibbons]

Ah, I see - yes, when using a chain of 2x 128x64s the start panel is in the bottom left, when viewing from the back.

Is swapping the position of the two rows of panels in your frame an option?

[bidmangler]

So yes, I did indeed have a "DUH!" moment - and flipped the cabling around. Now works perfectly. My only excuse is that I couldn't get my head around why the display would be mapped so that the top portion was in the 2nd half of the chain. However, it works so that doesn't matter!