Hello everyone
I have manufactured 16 x 48 1:4 scan panels and made display of 432 x 128
I am visually expereincing a weird problem. I can see vertical lines after 8th column on some panels. The weird thing is some panels are absolutely uniform. Only a few panels have random un - uniform brightness. And some panels have vertical lines of 1 x 16 which is my main problem.
Now this doesn’t look like a software issue because attaching that panel anywhere on the matrix shows the same pattern.
What I have tried to do :- Change driver IC’s, MOSFET, Buffer IC’s to check if it is a issue with my lot. But doesn’t seem so. Using IC’s from a perfect panel still gives the same result on a problematic panel. So I am not able to understand this hardware problem. The upper half 8 x 48 and lower 8 x 48 is completely unrelated so I am not able to understand how to vertical lines are being seen for the whole 1 x 16 coloumn. And I am seeing this after every 8th row. So there are 6 such vertical lines in some panels of 16 x 48.
Anybody has any idea what is going wrong and what I should check?
Cool setup.
You didn’t show what command line arguments you gave to rpi-rgb-panel.
Is this a single chain? (if so, your refresh rate must be terrible for so many pixels).
Did you make 3 different chains? How is this wired in the back?
What rPi are you using?
Thanks.
I have divided the display into 2-parts and using 2 raspberry pi CM3+ custom PCB
432 x 64 for one pi. 4 parallel chains.
I am keeping pwm bits to 1-2 so refresh rate is not a problem. I think after doing more tests we have eliminated various possible issues and boiled down to PCB manufacturing issue. Though it is hard to believe such variations from JLCPCB. But I have done every possible hardware and software test.
The 8th column remains dim no matter what ( Only for a few PCB’s). Even If I inter change the driver output with a bright one.
What software/hardware are you using? this lib does not support 4 parallel chains.
Are you using this lib?
if so, what command are you running in examples/demo to light up all the panels with 4 chains (which isn’t supported, so I’m confused)
I have already added support for Henner’s library for 6 parallel chains with Compute Module 3+.
Please link to your hardware solution and software you’re using.
Is anyone else using your improved solution?
It’s a bit hard for the rest of us to relate if we don’t have your hardware and software :-/
