P3 64x64 matrix (P3-32S-HL1.2) missing red on second half of panel

[zango-me]

Hi,

i got a few P3 panels (part no 2PH2962EA1 // https://de.aliexpress.com/item/1005005727115453.html) and they do not display red on the second half of the panels (the side away from the connectors)
Everything else looks okay tho, and the behaviour is across all 6 panels I got.

I checked all available options for the following parameters (not every combination tho, caus that would take ages):

--led-gpio-mapping
--led-multiplexing
--led-pwm-bits
--led-scan-mode
--led-row-addr-type
--led-pwm-lsb-nanoseconds
--led-pwm-dither-bits
--led-panel-type

and both configurations for the E address pin as well but nothing made it better (most changes only broke it more).

This is my current command I'm using to run the demo:
sudo examples-api-use/demo --led-rows=64 --led-cols=64 --led-parallel=1 --led-chain=1 --led-brightness=30 --led-rgb-sequence=RBG --led-limit-refresh=60 -D4

The Chip nearest to the connector is a DP245C

(I'm using a Pi4 with a passive adapter board and checked that the connections are correct and not flakey)

Does anyone have an idea what the problem could be?

[zango-me]

So I tried it with a Pi1 model B+ which I had still laying around and it seems to work with that (except some crazy slowdown when I address all 6 panels, which is expected due to the performance of the system I guess), is this some strange behaviour of the Pi4 or is there a GPIO broken on mine?

If so can I remap the broken GPIO somehow? (and how do I identify it?)

PS:
I use respbian lite on both, 32bit on the Pi1, 64bit on the Pi4 and I followed the troubleshooting steps (disableing audio driver and uninstalling the packages mentioned there) on both PIs

[davemaster]

Greetings,

You have only ONE unit of this panel? Have another one like 32x32?

Also, change this:

sudo examples-api-use/demo --led-rows=64 --led-cols=64 --led-parallel=1 --led-chain=1 --led-brightness=30 --led-rgb-sequence=RBG --led-limit-refresh=60 -D4

to

sudo examples-api-use/demo --led-rows=64 --led-cols=64 -D4

[zango-me]

Hi,
thanks for your quick reply

---

You have only ONE unit of this panel? Have another one like 32x32?

I have only 6 of the same type of panel, they all do the same but allso all work with the other Raspberry Pi (as mentioned) for some reason

---

sudo examples-api-use/demo --led-rows=64 --led-cols=64 -D4

That's what I started with when trying the panels out, but has the exact same behaviour.
(Well, colors are wrong cause my panels are RBG and not RGB but red is not working on the one half with both configurations, so it must be an addressing issue or something similar)

---

Results with the Pi1 as a driver:

And with the Pi4 (exact same command):

any other ideas what could cause this strange bahviour with the Pi4?

[davemaster]

ok

add in Rpi4 the led-gpio-slowdown option

now:

sudo examples-api-use/demo --led-rows=64 --led-cols=64 --led-gpio-slowdown=4 -D4

test, between 2-4 (even 5)

read this

[zango-me]

That option dosn't help, sadly

[davemaster]

With the RPi 4, are You using the SAME EXACT connections than the used with Rpi 1? U are using THE SAME adapter, cabling for both? Show pictures of BOTH