64x64 + Rasp Pi 3B+ | Stretched Output / Wrong Resolution

1

Hi,

I purchased a 64x64 LED-Matrix and am now trying out some stuff. Unfortunately I got some problems with my setup.

The Problem is, if I use:

–led-cols=64 --led-rows=64

the middlepoint of my output is outside of the panel, but seems to have the right resolution.

If I use:

–led-cols=20 --led-rows=64

The middlepoint seems to be (nearly) right, but the output is stretched by 3x.

Here is one picture I took from ./demo -D0 :

(using 64x64 as cols and rows)

20210216_205829
20210216_2058293456×4608 2.75 MB

Information in the Matrix:

This is the Amazon-Page of the Matrix:
64x64 LED-Matrix - Janhiny - (german)

I am using a Raspberry Pi 3B+ for controlling.
The OS is Raspbian Lite.
And this is the kind if command I use:

sudo examples-api-use/demo -D0 --led-cols=64 --led-rows=64 --led-show-refresh --led-slowdown-gpio=4 --led-pwm-dither-bits=2 --led-chain=1 --led-multiplexing=0

Thanks so far and have a nice day
Tobias

2

I can just upload one picture at a time due your rules.

So here is a second picture of the problem:

(using 20x64 as cols and rows)

20210216_205752
20210216_2057523456×4608 2.57 MB

3

And here’s a picture from the backplane of my module.

20210216_210201
20210216_2102014608×3456 2.63 MB

4

Hi,

i’ve got the same display, same seller, but diffrent from your’s
mine has label
P3(2121)64x64-32S-M3
and i got it early jan this year.
The display is working without any trouble…

5

Hi Jens,

thanks for your response.
Well, that means that I maybe have done something wrong with the connectors.
That’s the obvious conclusion for me.

I will check.

6

unfortunately it’s also possible they mailed you a different panel. Vendors change chips all the time and they’re not always compatible.

You can try all the command line options from the README.md in case any helps.

7

Hi Marc,

I already tried all the options. Unfortunately they didn’t help.
I also don’t have the time to write my own configurations to the code, mainly because I would have to dig into C. I’m not into coding for long time, now.

I think I just had bad luck with by panel. Maybe there will be a fix later.
Or I just buy another panel which works fine.

But nevertheless, thank you for your help.

8

Sorry, it’s frustrating that there are so many incompatible panels out there. Good luck finding some that work. If you want a vendor who is pretty reliable, you can try azerone. They’ve only shipped me panels that work (currently FM6126A and FM6127)
https://www.amazon.com/s?i=merchant-items&me=A1QIWERAQGCBKO