Author Topic: What do you use to send data for the P10 panels  (Read 6397 times)

Offline Bshaver

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Re: What do you use to send data for the P10 panels
« Reply #15 on: March 11, 2015, 03:19:17 PM »
I've done another test. The panels are directly attached to the Octoscroller with a 1meter long first ribbon cable, and sending data from FPP B+ sending Multicast to the listening BBB and it is very stable. :)
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Offline CaptainMurdoch

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Re: What do you use to send data for the P10 panels
« Reply #16 on: March 11, 2015, 03:53:47 PM »
Capt'n
I tested with a LONG cable from PI/Device to First panel - 1 Meter and the results were:

Captn Hat - very noisy - dropped pixels, severe lag in pinwheel and jumpy text
RTC Hat - Noisy, lag in pinwheel and butterfly and text
BBB Octoscroller - stable

I then replaced the 1 M long cable with a 12" cable - shortest I have ( to be able to still connect the device and the panel)

Captn Hat - noise improved - but VERY noisy when doing full color washes - butterfly or drape effects with xlights.fseq sequences. Text useable
RTC Hat - noise improved - stable on most fronts. Some lag on pinwheel. text usable
BBB - stable

Thanks.  That confirms a few things.  Some noise is cable length and some of the noise is just due to the software refresh on the Pi in the common RGBMatrix library code.  That might be helped a little by the changes that Henner has pushed to his repo recently.

And it further proves why we've been saying the BBB w/ Octoscroller is the recommended solution even though you can drive these directly off the Pi.  Once I get FPP upgraded to use a newer version of Henner's library, then I'll see about updating the PCB design to include level shifters to at least get it on par with the Adafruit hat.  Henner told me that he is going to be doing some testing as well, so he may come up with other optimizations.  One thing to keep in mind is that the more panels in a chain, the worse performance will be on the Pi doing PWM in software.  This is the big reason to use the triple-output support in the latest code Henner has added.  Rather than one chain of 6, you can have 3 chains of 2 and get much better quality.
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Chris

Offline Bshaver

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Re: What do you use to send data for the P10 panels
« Reply #17 on: March 11, 2015, 04:37:49 PM »
Yes, I know that we have the BBB outputs on the Wiki.. but It would be good to do a break test and where it would be 'reasonable' to run X number of panels on the PI with your pcb hat or rtc hat, etc. I think one of the benefits of having the RTC hat is the power barrel connector with screw terminals for a panel. You could, with a beefy enough power supply run everything off one cable :) attach wifi, and you are in business.

My Rons board will be here tomorrow, and i'll run the similar tests with the long and short cable on my 6 panels.

 

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