Hey all…back again 
@marcmerlin trying to copy your layout…
I have total of 15 32x64 panels wired up vertical and using the v-mapper:z. I cannot get it to show the demo 0 its way off?
im using this:
sudo ./demo -D0 --led-rows=64 --led-cols=160 --led-chain=5 --led-parallel=3 --led-pixel-mapper=V-Mapper:Z --led-no-hardware-pulse
I tried swapper the ribbon cables from the card to leds but still didnt work…
Welcome pointers or help on this thanks!
I would like to just show pictures and GIF/MP4 in the end…
Pro tip: any question that says “it doesn’t work” cannot except any help
What does “didn’t work” mean?
no picture?
bad layout?
other?
Need to see output
If you have no output, it’s not a layout issue.
Try something like this
~/rpi-rgb-led-matrix/examples-api-use/demo --led-gpio-mapping=regular --led-rows=32 --led-cols=64 --led-row-addr-type=0 --led-chain=5 --led-show-refresh --led-slowdown-gpio=2 --led-parallel=3 --led-pwm-dither-bits=1 --led-pwm-lsb-nanoseconds=100 --led-pwm-bits=7 --led-panel-type=FM6126A -D0
If you don’t get output with that, don’t bother with the mapper yet
thanks for the reply…
i used this command and the demo is working with a bit of flickering…
sudo ./demo --led-gpio-mapping=regular --led-rows=32 --led-cols=64 --led-row-addr-type=0 --led-chain=5 --led-show-refresh --led-slowdown-gpio=2 --led-parallel=3 --led-pwm-dither-bits=1 --led-pwm-lsb-nanoseconds=100 --led-pwm-bits=7 --led-panel-type=FM6126A --led-no-hardware-pulse --led-pixel-mapper=V-Mapper:Z -D0
So thank you for the suggestion, another forum member pinged me also and helped out with the command timing…
So demo is good
When i try to play a gif or avi file the colors do not match? see example of the gif i use and then the result? Same thing happens when i try a video file…
Is there something i can keep trying/changing so see if i get a better result?
here is the panel and im using a 40a power supply
thanks for the help/reply!
ok some progress…i used the RGB sequence and changed it to RBG…progress as i now have the yellow per the gif file. as you can see though its still not perfect…there is red on some panels only on the right?
here is the command i used:
sudo ./led-image-viewer homegif.gif --led-gpio-mapping=regular --led-rows=32 --led-cols=64 --led-row-addr-type=0 --led-chain=5 --led-show-refresh --led-slowdown-gpio=2 --led-parallel=3 --led-pwm-dither-bits=1 --led-pwm-lsb-nanoseconds=100 --led-pwm-bits=7 --led-panel-type=FM6126A --led-no-hardware-pulse --led-pixel-mapper=V-Mapper:Z --led-limit-refresh=260 -C --led-rgb-sequence RBG
how can i narrow this down? cause…thanks for the help!
and same with the demo D0 - red on the right side? all the panels are the same make/brand (same batch)
this shows the red bars on the right better. im at a loss with this. any pointers on what the red bars could be?
Yes, I have seen this before with FM6127 panels.
2 solutions I found
- power everything down (the panels and the rPi) and start over. It means the init sequence didn’t work right and the panel is stuck in a bad color mode
- I can sometimes fix it by running a demo as FM6127 instead of 6126, which sends a different init/reset sequence, and then re-run my code and the panels look good then.
hey…back and did you suggestions and still the same. I also checked the connections and swapped the left & right ports/panels…as you see if on the above picture. The red then went to the left set of panels. so i tried a different RGB card and the same so it looks like a software error not hardware?
Any other suggestions here please? thanks for helping!
is there a way to reset the panels? maybe send a reset or run a program?
RESOLVED
i went and checked the board documentation incase it had changed and they had.
it has a switch option on the board and this is what i changed. this removed the red bars
posting here incase someone else has this
learned a lot along the way
oooh, the RTC switch. Sorry that it was set wrong by default. I’m surprised that it’s still there honestly, not sure how many people use the RTC feature.
always a lesson 
thanks for all the tips tough./…
