Dim displays on latest waveshare panels

1

Hi all, is anyone else experiencing this? I have 2 waveshare 64*32 P3 panels which work great. I use them with with both rpi-rgb-led-matrix and pixelpusher and LED Lab. I recently received 2 more and they are very dim when used in exactly the same setup. :frowning:

I noticed that the latest ones use a different chipset. The first pair that work well seem to be populated with a JXI JXI5020GP LED driver chip. The second pair that are dim use the superchip FM6047 LED driver. Iā€™ve enquired with Waveshare and they are investigating, but no response so far so I thought I would ask here.

I am using an Adafruit bonnet modified for PWM to drive the boards from a Pi Zero 2 WH with a 50W high quality power supply. Same result without PWM. Same results with 1,2 or 4 boards.

Example command used is:

sudo /home/pi/rpi-rgb-led-matrix/examples-api-use/demo -D 4 --led-cols=64 --led-rows=32 --led-gpio-mapping=adafruit-hat-pwm --led-chain=4 --led-parallel=1 --led-pixel-mapper U-mapper --led-pwm-bits=11 --led-brightness=100 --led-show-refresh --led-limit-refresh=120

I have played with different settings for PWM bits, LSBā€¦ audio is off. And in all cases 2 of the boards are bright and the other 2 are dim.

The setup

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image1715Ɨ1271 250 KB

The result

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image1609Ɨ921 243 KB

2

Brightness level 100 is not full brightness. I think the brightness range is 1-255.

3

note that brightness between panels with different chips, will not be the same and there isnā€™t much you can do about it except donā€™t mix and mach.
I have some FM2616A and FM2617 panels, and the brightness is not quite the same either.

4

Hey ,just fell over this and found a ā€œofficialā€ solution look at
https://www.waveshare.com/wiki/RGBā€“Matrix-P3-64x32-Reginit

the Script is for one Panel only for more panels you need to modify the ā€œMaxLEDā€ Value before compiling.

5

absolutely, you can adjust or this in software if you are willing to do the work to do a brightness mapping in software and adjust the matrix values accordingly for each panel.
Itā€™s just more work than Iā€™m willing to do, so I make sure to have matching panels :slight_smile: