RGB Pixel and Decoder Testing

dmoore

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ThaiWay said:
You can see that the MPH Nodes are of a much better quality build....

That's a big motivation for me to explore this promising option.
Of course... these are Christmas lights... how good do they need to be? ;)

Thanks for ordering this and doing the testing... my credit card is getting worn out with all the other items I've purchased from China. :) Can't wait to see the final results.
 

ThaiWay

1500 C9's are not green
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dmoore said:
So does this mean that if he flips it around and goes from 0 to 31 for the intensity, that it should work? 32 levels is still better than the poor fading of most LED strings hanging off an A/C controller.
Drawing at 31 makes no difference in the flicker other than it is not as bright. Forgive my ignorance about bits and bytes but I think we're talking about apples and oranges now.

John
 

chilloutdocdoc

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I wonder if the flickering issue is caused by the decoder recieving data other than those 32 levels, and having to convert it to one of the levels it accepts, it's potentially a lot of conversion to do at once for a chip.

I would imagine that if you used the numbers that are put into the data-sheet, that it wouldn't flicker as much... Just my guess, not having a product to test out.
 

Vairmoose

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back to the data for just a sec.... just some thoughts the typical usage for DMX512 is a large packet of (8 bits x 512 address) = 4096 bits (plus the normal check bits, etc) .... if they are only using 5 bits for each color... that means that the 'expected' data coming into the chip is in the form of 2 byte (16 bit) for each address. and potentially 256 nodes could be addressed (all three colors controlled). The problem is that VIXEN and LSP do not know how to crunch the data down ... a new plugin would be needed to do the crunching.... tranforming 3 bytes (for the RGB from Vixen or LSP) into a 2 byte data packet.

Larry

(Added)... something to try...(assuming vixen here) set the first channel (red) to value 247, second channel (Green?) to 0, third channel (blue) to 247, ... fourth channel (red) to 0... and so on... if my guess is approximately right, you should see all the nodes show as solid red... then.. change the order, channel 1 to value 7, channel two to 192, channel three to 7, four to 192 etc (continue for all the channels) .... you should be seeing solid green then with no flicker ......

(just an idea) ..

OK... my bad I misunderstood (apparfently) what was being stated. I perceived that maybe the string was not treue DMX but a basterdized version. Ok... back to the regular channel
Larry
 

rrowan

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Hi Larry,

Now you got me confused.

I always assume that one node would take 3 channels. Ie: Node 1 = dmx channels 1,2,3 each gets a 0 to 255 brightness level

Like the decode is 360 channels but controls 120 nodes (lights)

Could be wrong, could be right - still learning this rgb world

Cheers

Rick R.
 

chilloutdocdoc

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The decoder is the portion that takes the 3 channels IN from the computer, and converts it to the 3 channels out for the nodes i'll make a little table/diagram/drawing thingie later.

The computer still outputs 3 x 8 bit channels, the decoder converts that to 3 x 5 bit channel. The decoder, not the computer, outputs 5bit data.

edit: added picture

[attachimg=1]

This is my understanding of the data flow for those that need a more visual representation.
 

Attachments

rrowan

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chilloutdocdoc said:
The decoder is the portion that takes the 3 channels IN from the computer, and converts it to the 3 channels out for the nodes i'll make a little table/diagram/drawing thingie later.

The computer still outputs 3 x 8 bit channels, the decoder converts that to 3 x 5 bit channel. The decoder, not the computer, outputs 5bit data.
Maybe it was Moose Math :D

Rick R.
 

ThaiWay

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Well after some further testing it appears the LT6803 Decoder I got has some defective DMX Code. The RGB Nodes work great with the Decoder in standalone mode, but not in DMX. More research is needed but communicating with the manufacturer through 3rd parties takes time, and my English-speaking rep is out of office until Sunday. In the mean time be sure to check out Tabor's success in the new RGB subforum: http://forums.auschristmaslighting.com/index.php?topic=134.new#new

John
 

ThaiWay

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The PIC in the Decoder must be locked. When I try to read it, I get "No device found."

In an amazing bit (to me!) of micro repair, I soldered some fine solid wire to the four legs of the PIC that I broke off when the small screwdriver I used to pry it from its socket slipped. The PIC is unreadable but still works - albeit defectively in DMX mode - when I replaced it in its socket.

John
 

clueless

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I received my order of 120 nodes in the mail today. It looks as if they have changed the wiring a little bit. Adding a connector and another set or power leads. The one connector has a Blue, Green and Yellow wire on them then they have left the connector off two other leads which are Red and White. I can see why they would have done this. The only question I have is that the white wire looks like it is soldered to the same spot on the board as the Yellow wire. Which then would say the yellow wire was the ground instead of the blue? I will attach an image.

Others input would be appreciated

http://richserv.com/forum_images/imag0121.jpg

thanks
Ryan
 

fasteddy

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clueless said:
I received my order of 120 nodes in the mail today. It looks as if they have changed the wiring a little bit. Adding a connector and another set or power leads. The one connector has a Blue, Green and Yellow wire on them then they have left the connector off two other leads which are Red and White. I can see why they would have done this. The only question I have is that the white wire looks like it is soldered to the same spot on the board as the Yellow wire. Which then would say the yellow wire was the ground instead of the blue? I will attach an image.



Others input would be appreciated

http://richserv.com/forum_images/imag0121.jpg

thanks
Ryan
That looks odd, I dont have a set of these strings to compare but it doesnt look right. Do they work? If your having issues with them then talk to Ray, he is very responsive to these issues.
 
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