DMX to WS2801 Pixel Bridge

[RPM]

Like many others here, I've been playing with some of the 2801 RGB LED pixels, so I've written firmware to run them.

It's a very simple design with an Atmega88, an RS485 driver, and a few supporting components.

I have two variants of this board. The first is a single string driver board and will run up to 50 RGB nodes, and the second is a bridge board that will take a DMX universe (504 channels actually) and divide those channels across 4 ports of 42 RGB LED's.

Here's a preliminary schematic of the single string driver.

Once I've had a chance to fully test the firmware, I'll post it.

[n8huntsman]

What are your plans for this project? Will you be making boards, and what do you expect the cost per controller to be?

[Entropy]

ASM or C?

[RPM]

ASM or C?

It's written in ASM.

[RPM]

What are your plans for this project? Will you be making boards, and what do you expect the cost per controller to be?

At this point, I'm not really sure.

I'll post the schematics and firmware, I'll probably get a few boards made for my show.
There are lots of other pixels projects going on right now, so it all depends on if there is enough of a demand to get a large amount of boards to make it cost effective for a group buy.

I don't have any cost estimates yet, but I don't see it being very expensive.... probably around $20 or so for the 4 port bridge, and less for the single string version.

[RPM]

A quick video I took today of my single string DMX Pixel driver. I used one of my Grinch DMX boards and modified it to run the pixels.

Nothing special as far as sequencing... just a few random patterns in Vixen.

This is a single string of 50 RGB nodes (150 DMX channels).


http://www.youtube.com/watch?v=MnQeJTBUwEg

[Twinkleclaus]

Any progress on the code? I'm going to be ordering some 328P microcontrollers soon for another project and was thinking about adding a few 88's to build a few of these.

[RPM]

Any progress on the code? I'm going to be ordering some 328P microcontrollers soon for another project and was thinking about adding a few 88's to build a few of these.

I have the single string version done. I just finished the 4 string version last night and need to do a little more testing on it.

I'll post the code soon. I'll attach the schematics for the 4 port version here.

I'm still working on a board layout for both designs, but they should be easy enough to protoboard.

[kychristmas]

What kind of strings are those? There are so many choices and I am way overwhelmed. I would like to play around with them, but just don't know which ones to go with.

Edit: I see from the original Title that is WS2801, but where did you purchase them from?

[RPM]

What kind of strings are those? There are so many choices and I am way overwhelmed. I would like to play around with them, but just don't know which ones to go with.

Edit: I see from the original Title that is WS2801, but where did you purchase them from?

The nodes in the video are from Ray Wu's online store, here
http://www.aliexpress.com/fm-store/701799/209889132-404056686/12mm-WS2801-pixel-module-IP68-DC5V-input-full-color.html

They are in a "lot" of 50 nodes, which just means there are 50 RGB nodes on each string. I bought a couple of that type, and a couple of these
http://www.aliexpress.com/product-fm/342765392-5050-RGB-pixel-led-module-2801IC-256level-scale-DC5V-input-0-3W-wholesalers.html
to use for testing, and I'll be using them for my show this year.

One thing to keep in mind if you order any of these nodes, they are originally designed to use in signs, so the wire length between nodes is only about 3".
They can be ordered with custom lengths, so this is what I did for two of the strings.

I got them with a 12" length between nodes and I plan on using them on my roofline with some clear C9 covers on them, like these http://www.martinxmas.com/download/C9_cover.png (http://www.martinxmas.com/download/C9_cover.png)
This picture shows a C9 cover with one of the 5050 pixels like the ones above mounted in it.

[n8huntsman]

I went with these: http://www.aliexpress.com/fm-store/701799/209889132-404056686/12mm-WS2801-pixel-module-IP68-DC5V-input-full-color.html
They smell like all sorts or banned chemicals.

[intwoit2002]

How many levels does the 2801 support for dimming? The video looked really nice, just curious. I want to do something also, but so many options.

Thanks,
Al

[gunther]

RPM,

For the quad string version, does it handle more than one DMX universe? If so, is it using hyperDMX or ???

[n8huntsman]

The 2801's are 8 bits per color for dimming.

How many levels does the 2801 support for dimming? The video looked really nice, just curious. I want to do something also, but so many options.

Thanks,
Al

[smartalec]

RPM,

For the quad string version, does it handle more than one DMX universe? If so, is it using hyperDMX or ???

i think only the tp3244 does hyperdmx with the DR4, unless im wrong an there is other products

[RPM]

I went with these: http://www.aliexpress.com/fm-store/701799/209889132-404056686/12mm-WS2801-pixel-module-IP68-DC5V-input-full-color.html
They smell like all sorts or banned chemicals.

Yup. they do! Not something you would want to leave in the house!

[chelmuth]

I have two variants of this board. The first is a single string driver board and will run up to 50 RGB nodes, and the second is a bridge board that will take a DMX universe (504 channels actually) and divide those channels across 4 ports of 42 RGB LED's.



The four port would have a single universe and four strings of 42 pixel count.

[RPM]

How many levels does the 2801 support for dimming? The video looked really nice, just curious. I want to do something also, but so many options.

Thanks,
Al

Al,

They are 8 bit dimming per color (255 steps), 24 bits per RGB node.

Yes, there are lot of options out there. These designs are intended to be a simpler solution for someone wanting to get into RGB nodes without all of the complicated supporting hardware.

[RPM]

RPM,

For the quad string version, does it handle more than one DMX universe? If so, is it using hyperDMX or ???

Just one universe using standard DMX. I am thinking of adding an option (on board jumpers) to use the 2nd wire pair on the Cat5 input connector to allow for selecting DMX universe1 or DMX universe2. The DMX spec allows for two universes to be transmitted on the same Cat5 cable on different pairs, so going this route will help to double the amount of channels over one cable.

[RPM]

The four port would have a single universe and four strings of 42 pixel count.

I do have provisions in the firmware code to change the pixel count per port (up to 512 channels), but this is something that need to be changed in the source file and then recompiled.

[RPM]

Any progress on the code? I'm going to be ordering some 328P microcontrollers soon for another project and was thinking about adding a few 88's to build a few of these.

It will need to be compiled for the specific processor, but the source code will work on the Atmega88,168,328 processors.

[Matt_Edwards]

RPM,
Are you use the AVR's SPI function for the 2801?

[RPM]

RPM,
Are you use the AVR's SPI function for the 2801?

Yes, I use the hardware SPI port.

[RPM]

As promised, the schematics and source code for both DMX-2801 pixel bridge board variants.

I have not yet design PC boards, but I will be doing this soon.

[Twinkleclaus]

Looks great! Can't wait for my 88's and 328's to arrive to test out.

[Matt_Edwards]

I would build one tonight, if only I had some 2801 based lights. Might need to get me some.
Great work - as usual.

[mschell]

Looking very good. This is another option for the DMX->pixel control.

Do you have any plans to implement anything else besides 2801 pixels?

[RPM]

Looking very good. This is another option for the DMX->pixel control.

Do you have any plans to implement anything else besides 2801 pixels?

It's a possibility, but I only have 2801 pixels to test it with. I wrote the output routine so it can easily accommodate other pixel types though.
What other type were you think of?

Robert

[mschell]

6803, 1804, or some of the new stuff - 9318?

[RPM]

6803, 1804, or some of the new stuff - 9318?

If I can get my hands on some, I could include them.
They aren't that difficult to interface as most variants use the same data/clock pin arrangement, it's just the data packet format that changes.

[Entropy]

I really need to get some 2801 strands. Once I do, I should be able to release a C version of the firmware for this design fairly easily that us mere mortals can understand. :) (I already have all of the DMX reception stuff working, just need to rip out my PCA9635 code and replace it with 2801 code.)

[RPM]

Once I do, I should be able to release a C version of the firmware for this design fairly easily that us mere mortals can understand. :)

That's why I try to document my code as much as possible... to make it easier to understand what it does ;)

[Warlock]

Great work as always Robert...I guess the next challenge is trying to make it work for the Helix ??? Please.....

[DynamoBen]

Great work as always Robert...I guess the next challenge is trying to make it work for the Helix ??? Please.....

Can't the Helix send DMX, if so you are good to go? If it can't have Greg get in contact with me I have propeller code he could use to drive the strings directly.

[Warlock]

Would the code you have for the prop chip disable the other or add to what he already has ??? Meaning would it disable it's normal functions or add to it ???

[DynamoBen]

Would the code you have for the prop chip disable the other or add to what he already has ??? Meaning would it disable it's normal functions or add to it ???

Should add, but it depends on the code he has in place already.

[RPM]

Would the code you have for the prop chip disable the other or add to what he already has ??? Meaning would it disable it's normal functions or add to it ???


Joe, I think what DynamoBen is saying is that he has a code "add-on" to Greg's code (which he would have to write into his firmware) for adding DMX functionality to the Helix controller, not replacement code for it.

AFAIK, The latest version of Helix code has DMX functionality, but I'm not sure how many channels or ports it can be used with.

If you drop an email to Greg, I'm sure he can help you out.

Robert

[Matt_Edwards]

A fellow member Loaned me a string to play with.

RPM, once again you hit the mark with a simple but effective design.
I used one of my DMX Mega Break out boards to test it and was up and going in less than 45minutes.



http://www.youtube.com/watch?v=0Pb_pDWMMkI

[RPM]

A fellow member Loaned me a string to play with.

RPM, once again you hit the mark with a simple but effective design.
I used one of my DMX Mega Break out boards to test it and was up and going in less than 45minutes.

Cool... now to get more channels down the DMX line. I'm thinking of using the HyperDMX protocol to do this.

Gotta get back to my DMX dongle firmware to see what I can come up with ;)

[RPM]

I just sent out to have some boards made up of both designs.

The single port version is all SMD and the board very small at 0.7" X 1.6". I intend on using a small piece of 3/4" conduit to mount it in, with caps on both ends. One side will directly connect to the pixel string, and the other will have a 4 pin waterproof connector on it.

The quad port version is a bigger at 2.45" X 3.3". I have included jumpers on the board to be able to select DMX universe 1 or 2, which is pins 1&2 or 3&6 on the Cat5 connector.

[n8huntsman]

Can we summarize a bit? Quad version is 2 universes? Does this have two DMX inputs? Is there a pixel limit, other than that of the DMX universe? What is the current capacity at 5v?

[RPM]

Can we summarize a bit? Quad version is 2 universes? Does this have two DMX inputs? Is there a pixel limit, other than that of the DMX universe? What is the current capacity at 5v?

The board uses one universe for 4 ports capable of driving 42 RGB nodes each. This comes out to 504 channels total per board.
What I have done is added the ability to select 1 of two pairs of wires on the cat5 cable. While the board only accepts 1 universe, the ability to use either pair of wires on the cable will help to reduce the amount of DMX cables somewhat.
The ANSI E1.27-2 standard DMX pinout allows for a second data pair on pins 3 & 6, so I am using this to take advantage of the extra pairs going to the pixel bridge. This way two boards can be daisy chained on the same cable, and the universe select jumpers determine which DMX universe they respond to.

The current capacity at 5V is 3A per port.

[jstjohnz]

Probably a bit late since you have ordered boards, but I was going to suggest that you use the semi-standard string connector pinout originally used by mrpackethead, also used now by myself. It's the same connector, 4-pin .1" polarized header, but we have +V and GND reversed from your layout (I think). It would be nice to have pin-compatibility for pixel string wiring between several designs. I think we're using the same 4-pin waterproof cables also (MPH uses something different I believe). I am using BLUE for clock and GREEN for data.

-jim-

[RPM]

Probably a bit late since you have ordered boards, but I was going to suggest that you use the semi-standard string connector pinout originally used by mrpackethead, also used now by myself. It's the same connector, 4-pin .1" polarized header, but we have +V and GND reversed from your layout (I think). It would be nice to have pin-compatibility for pixel string wiring between several designs. I think we're using the same 4-pin waterproof cables also (MPH uses something different I believe). I am using BLUE for clock and GREEN for data.

-jim-

Jim,

Where can I find the pixel pinouts? I only ordered 10 boards, so it's no big deal to change the connector layout.

Robert

[n8huntsman]

Where are you using these?

...4-pin waterproof cables...
-jim-




Where can I find the pixel pinouts?
Robert

The pinout can be found in the e680 manual...
www.sandevices.com/documents/E680doc.pd

[P. Short]

I think that you mean

http://www.sandevices.com/documents/E680doc.pdf

[jstjohnz]

Jim,

Where can I find the pixel pinouts? I only ordered 10 boards, so it's no big deal to change the connector layout.

Robert

This is going to be crude. Looking down at the 4-pin polarized male header on the PC board (polarizing tab at top):

---######---
| |
| + ck dt - |
| |
--------------

From looking at your board layout, I believe you are using the same connector, (Molex KK series 4-pin male .1" header, polarized) with clock and data in the same positions, but your + and - are reversed from mine. I copied this pinout from a board layout published by MPH when I was laying out my board. I just figured it made sense to try and standardize when possible. Would be very handy I think to be able to swap swings from controller to controller without having to re-wire.

Are you using the 4-pin waterproof cables from Ray Wu?

[jstjohnz]

Where are you using these?

The pinout can be found in the e680 manual...
www.sandevices.com/documents/E680doc.pd

I ordered a bunch of these in 5 ft length from Ray Wu, waterproof circular 4-pin connectors, male on one end, female on the other. I cut them 18" from female end, that piece wires to the 4-pin molex connector for the board, the other piece wires to the pixel strings. For strings within 5 ft of the controller just plug in, for longer lengths use an un-cut cable as an extension. Search Ray Wu's store for "4 core waterproof". I think he can get them any length, and the price is reasonable even with shipping.

[n8huntsman]

Ahh, I see. I wanted to use those but being cheap, I opted for the 12" molex extensions from monoprice for $.73 each. I would have liked for them to have been waterproof though.

[RPM]

I just finished firmware for the LPD6803 Pixels tonight.

I only have 6 of the 6803's and I need a longer pixel string to fully test it out... anyone want to help with testing?

Robert

[RPM]

OK, the single string bridge firmware is now 2801 and 6803 pixel compatible.

I'm now working on the quad port version of firmware which will also support both protocols and be capable of selecting pixel protocol on a per bank basis via on board jumpers.

My thanks goes out to member Twinkleclaus for loaning me some 6803's to help get the protocol written into the firmware.

Robert

[Twinkleclaus]

OK, the single string bridge firmware is now 2801 and 6803 pixel compatible.

I'm now working on the quad port version of firmware which will also support both protocols and be capable of selecting pixel protocol on a per bank basis via on board jumpers.

My thanks goes out to member Twinkleclaus for loaning me some 6803's to help get the protocol written into the firmware.

Robert

Not a problem. The pixels certainly went to a great cause!! This is great work.

[funky2011]

Hi,

can somebody help me on how to use atmega32 or atmega8535 instead of the atmega88 here. i have a lot of 32 and 8535's and can't find 88's where i am living. Would be great if you could tell me what to change in the source asm file.
thank you

EDIT: Atmega8 is also possible...

[RPM]

Hi,

can somebody help me on how to use atmega32 or atmega8535 instead of the atmega88 here. i have a lot of 32 and 8535's and can't find 88's where i am living. Would be great if you could tell me what to change in the source asm file.
thank you

EDIT: Atmega8 is also possible...

Neither of those will work without a considerable rewrite of the firmware.

Those parts have a maximum clock rate of 16mhz and this firmware is written for a 20mhz clock, so all of the timing routines will need to be recalculated for the clock difference, and some of the commands may be different.

The atmega8535 doesn't have enough SRAM. Although the atmega8 and atmega32 do, some of the registers used are different and would need to be changed.

[CaptKirk]

RPM,

This looks like a fantastic design! How is the quad design going? What do you see as the max length between the controller and the first node in a string? Could this be adapted to work the 12v strings on Ray's site (http://www.aliexpress.com/fm-store/701799/209889132-380805820/128-node-led-pixel-string.html)? If so, do you think with the 12V VCC able to go out further that the single could drive a 128 node string? Unfortunately, I seem to be stuck with some, they are 12v and 3 wire, and a mutual "friend" has mucked with their design. :-( If it ends up that I do own these permenantly, then would sending you some help to make them usable with your controller? I think Ray would be very happy to have a reliable controller available to run these!! D

THX, Kirk

[funky2011]

Hi RPM,

thanks for your reply. Ok, i ll throw them to the garbage :)
What about the atmega48? Can i use it without any changes in the source? Looks like 4k is enough for your code... or am i missing something?

[RPM]

Hi RPM,

thanks for your reply. Ok, i ll throw them to the garbage :)
What about the atmega48? Can i use it without any changes in the source? Looks like 4k is enough for your code... or am i missing something?

It's not so much the code space as it is the SRAM available. The DMX receive buffer is stored in SRAM, so you need to have at least as much as the Max number of DMX channels plus some extra for processor use. 512 bytes of SRAM in the Atmega48 means you would not be able to use it for an entire 512 channel DMX universe, so it would only be useful for the single string variant.

[funky2011]

Hi RPM,

I see. So i definitely will use an 88.
One more question:
Is it possible to use an entire universe of 512 channels with a single string version? Or do i have to use the 4 port version and divide the channels of 1 universe to four?

Thanks again

[Matt_Edwards]

Hi RPM,

thanks for your reply. Ok, i ll throw them to the garbage :)

Not all is lost. atmega32 or atmega8535 can be used for other Dimmers.

[funky2011]

Hi Matt,

i used them already in other dmx led dimmers, otherwise i would not have so many of them ;) But the cabling hassle and the cost for one pixel is too much when you decide to make a 1024 channel pixel thing. The 2801 is quiet cheap and much more easy with auto adressing etc. (Thanks to RPM)
i like your site btw. But where is the link to your store?

[Matt_Edwards]

RPM,
Do you have an updated firmware for the Quad DMX to WS2801 Pixel Bridge?

[RPM]

RPM,
Do you have an updated firmware for the Quad DMX to WS2801 Pixel Bridge?

I'll attach it here along with the schematics.

Robert

[enlightener]

Hi RPM,

Thanks for posting this DMX bridge! I built a single string version using the Atmega328 and it works great. The only thing I noticed is that it will not control more than 25 RGB LEDS (75 channels) using Vixen. I know the 50 LED string is good because it works using some stand alone Arduino programs. Any ideas?

Regards,

-Tim

[fathead45]

hey rpm, i just seen this and have some questions that i didnt see replied to or were answered but never heard if they were implemented

-Can you eventually be able to put a full univ on a single port?
-I seen you talked about hyperdmx in the 4 port. did that ever get implemented? if it did will the e131 to dmx support it as well?
-any idea on the max refresh rate will be with a maxed out board?

i guess that is it for now. im just trying to research all my options for next year as i dunno the status of the TP3244

[enlightener]

Hi RPM,

The problem is solved.

It turned out to be a Vixen setup issue. I set the channels to 150 on the main screen, but I did not initialize the DMX interface to have 150 channels when the sequence was first created.

It works perfect now with all 150 channels.

Thanks again,

-Tim

[mstevica]

I'll attach it here along with the schematics.

Robert
Do you have an updated pcb and .hex for the Quad DMX to WS2801 Pixel Bridge?

[mstevica]

RPM gave you to set the hex for this?
Thank in advance for your response!

[cenote]

Is there any chat about these, for another board run? Be interesting on getting a couple.

[Bretk]

I'd be interested in a few of the singles too

[Zeph]

I'm interested too, if this project resurfaces.

I hope RPM is ok.

[CaptKirk]

RPM gave you to set the hex for this?
Thank in advance for your response!

Did you look here:

http://shop.martinxmas.com/attachment.php?id_attachment=23

[Aurbo99]

I'm in for at least 3 if you do another board run.

HURRY! HURRY! HARD!

[fathead45]

same here. i would be in for atleast 4 boards if not more on cost.

[RPM]

Hi guys... haven't been on here much lately. Life sometimes gets in the way, you know.

Anyway, I did have some boards made up for this design, but they were specifically designed for my show but I never did a group buy for them, mostly because they use a different pinout for the pixel connector than the "standard" used by others (the supply + and - is reversed).
I do have a few left so if anyone would like to get one, PM me.

Here's a pic of a built board

13491

[budude]

Hey Hey - - welcome back Robert!

[fathead45]

pm sent rpm:)

[ukewarrior]

2801 vs. 2811 at Ray's store !??

Ray store now states that his 2801 strings now use a 2811 chip.
Are these backward compatible with the 2801?

[timon]

No, the 2811 is a three wire design. Rumor Has it that the 2811 is the same as the 3001 and 3005 but it's not clear if this is correct.


Sent from my iPad using Tapatalk

[ukewarrior]

Hmmmmmmmmm

Are all our 2801 designs going obsolete?!!?

No, the 2811 is a three wire design. Rumor Has it that the 2811 is the same as the 3001 and 3005 but it's not clear if this is correct.


Sent from my iPad using Tapatalk

[fathead45]

ed was saying it uses a different encoding than the 2801. im still buying a ton of 2801 for this year and i think you can still get them from ray if you ask.

[ukewarrior]

I found a better price than ray.
58cents, shipped.

ed was saying it uses a different encoding than the 2801. im still buying a ton of 2801 for this year and i think you can still get them from ray if you ask.

[mschell]

I found a better price than ray.
58cents, shipped.

Wanna share?

[ukewarrior]

You can hardly buy dumb pixels for this price
http://www.aliexpress.com/product-fm/523584176-led-module-12mm-WS2801-pixel-module-IP67-DC5V-input-full-color-2801-pixel-led-pixel-module-wholesalers.html

Wanna share?

[angus40]

Take a close look at the picture of these . There is no ic , hmmm

[mschell]

The title of the item and the description/picture don't match up.

title lists WS2801 chip, but the description does not.

Good eyes!

[Zeph]

Ray sells a similar string at $0.53, it's the shipping that make a difference. For 200 pixels, Ray would be $126.35 with shipping, while your source would be $105.26, about 17% less.

But the vender is pretty new (less than a year old with only two real feedbacks total!), has shipped their first order of this item only recently with no feedback yet - and the discrepancies above would need to be investigated; you get to find out how well they communicate!

Some of us will be interested in how it turns out if you do order.

[mstevica]

.hex not here.
If anyone can set up a .hex
I need a hex for the DMX-2801-QUAD-V1_1F
RPM HELP

[RPM]

See reply #24 in this message thread. The full project file with .HEX is here
http://doityourselfchristmas.com/forums/showthread.php?15286-DMX-to-WS2801-Pixel-Bridge&p=154332#post154332


As promised, the schematics and source code for both DMX-2801 pixel bridge board variants.

I have not yet design PC boards, but I will be doing this soon.


.hex not here.
If anyone can set up a .hex
I need a hex for the DMX-2801-QUAD-V1_1F
RPM HELP

[Zeph]

Any chance of more product in the store, Robert? I'm very impressed with your designs, but I'm not taking on etching boards yet (enough new stuff on my plate!).

[mstevica]

See reply #24 in this message thread. The full project file with .HEX is here
http://doityourselfchristmas.com/forums/showthread.php?15286-DMX-to-WS2801-Pixel-Bridge&p=154332#post154332


That I saw.
I need a hex for this:
http://doityourselfchristmas.com/forums/showthread.php?15286-DMX-to-WS2801-Pixel-Bridge&p=165783#post165783

[fathead45]

thanks rpm, got my boards:)

now any jw if you got the bom finished?

[RPM]

Try this BOM

http://www.mouser.com:80/ProjectManager/ProjectDetail.aspx?AccessID=703130cf9e


thanks rpm, got my boards:)

now any jw if you got the bom finished?

[Matt_Edwards]

RPM,
It is good to see you tapping the keyboard here again mate.
Welcome back.

[joeengler]

Ray sells a similar string at $0.53, it's the shipping that make a difference. For 200 pixels, Ray would be $126.35 with shipping, while your source would be $105.26, about 17% less.

But the vender is pretty new (less than a year old with only two real feedbacks total!), has shipped their first order of this item only recently with no feedback yet - and the discrepancies above would need to be investigated; you get to find out how well they communicate!

Some of us will be interested in how it turns out if you do order.

Make sure to only use Ray's online price as a guide, Every quote I have gotten back from Ray the shipping was a lot cheaper then on line and a few times he gave me a break on a item price.

[RPM]

Not to mention that Ray will also make your pixel strings exactly how you want them.
He can also make them to order; custom number of pixels, wire length between pixels, wire length to first pixel, etc. Most of the time the cost difference is none or minimal depending on what you want.



Make sure to only use Ray's online price as a guide, Every quote I have gotten back from Ray the shipping was a lot cheaper then on line and a few times he gave me a break on a item price.

[fathead45]

hey rpm, the bom looks good but i messed it up. i didnt know that if i removed stuff it would take it out of your link above. so the bom is messed up. sorry rpm.

[RPM]

Not to worry.... the BOM is "read only" and won't be affected by any changes you make.
you may have to clear out your browser cache to be able to see the original BOM though..



hey rpm, the bom looks good but i messed it up. i didnt know that if i removed stuff it would take it out of your link above. so the bom is messed up. sorry rpm.



Sent from my SAMSUNG-SGH-I897 using Tapatalk

[fathead45]

oh ok cool, thanks Robert.

[timon]

"




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[Mac Hosehead]

I am a noob when it comes to pixels. So I thought I would build your design and buy a string. I built the quad output version and managed to brick a microcontroller with a wrong fuse setting. The second try went better and although I had no strings the output "looked good" on the scope.

I ordered a string from here:
http://www.ebay.com/itm/New-Waterproof-50-LED-Colorful-String-Smart-RGB-Pixel-Direct-Light-Lighting-1-/350503491391?pt=LH_DefaultDomain_0&hash=item519ba2d73f#ht_3188wt_1211
In hindsight this was another noob action since I had no idea what driver chip these were based on and I was not sure if they would work with your controller. Luckily they worked with the LPD6803 setting. I have since ordered another string of a different style from Ray.

I like your design because it is small with few components. As cool as pixels seem to be, I can't see spending over a grand on them as others appear to be doing. I would also like to find a way to record the output from Madrix and play it back on an open-source controller. A poor-man's LED matrix if you will.

TYVM

-MH

[fathead45]

ok so i have my first one built. now a question now that i was thinking. jw if these are default to 1 and 2 univ? so i cant change that? also is there no way to set a start address of each just in case i only have a few pixels on each one?

also is the firmware still set for only 1 univ split between the 4 univ?? sorry for all the questions lol.

[fathead45]

still looking for answers to questions above^^^^^^

also one more, can i run more than 42 off 1 port, im in need of 50 per port for 3 ports.

[Mac Hosehead]

still looking for answers to questions above^^^^^^

also one more, can i run more than 42 off 1 port, im in need of 50 per port for 3 ports.

If you examine the assembly source code, it looks like this can be accomplished. I would try changing BANK_CHANNELS to 150 and then deleting the code for OUTPUT CHANNEL BANK 4.

-MH

[fathead45]

ok thanks. sorry im not a code monkey lol.

[Mac Hosehead]

I tried out this method for dimming 6803 pixels on RPM's design:
http://doityourselfchristmas.com/forums/showthread.php?20500-WS6803s-New-life-for-old-pixels
If I had all 4 outputs enabled, it flickered pretty badly. So I disabled 3 outputs and left one enabled and I could not notice any flicker. It is nice to see the brightness change with each DMX step.

BTW, I'm not a code monkey, more like a hack monkey.

-MH

[Mac Hosehead]

I tried out this method for dimming 6803 pixels on RPM's design:
http://doityourselfchristmas.com/forums/showthread.php?20500-WS6803s-New-life-for-old-pixels
If I had all 4 outputs enabled, it flickered pretty badly. So I disabled 3 outputs and left one enabled and I could not notice any flicker. It is nice to see the brightness change with each DMX step.

BTW, I'm not a code monkey, more like a hack monkey.

-MH

I went to 127 steps instead of 255 and I was able to get all four outputs working acceptably. I can barely notice a little flicker on the first two steps but I have to look closely. I am attaching the modified source code if anyone wants to try it out. It's a keeper for me. Of course, this is only for 6803 pixels. Thanks go to RPM for the hard work.

NOTE: I am using a ATMEGA328P processor. If I remove the comment on an include statement AVR Studio complains. Your assembler might need the proper include statement for the processor you are using.

-MH

[Matt_Edwards]

Great work.
What happens when you increase the spi clk. Does the flickering get worst or better?

[fathead45]

what programmer do i need to reprogram these?

[Mac Hosehead]

@Matt_Edwards
No changes were made to the output routines, only the way data is supplied to the routines. Originally data was supplied via a look-up table with 32 levels. The change looks at the lower 3 bits of DMX and adjusts the data to achieve a virtual 127 levels. I'm sure more optimization is possible but at present it looks good enough for anything I'm doing. Other changes can be easily made such as strings with different lengths.

@fathead45
There seems to be a myriad of AVR programmers. The one I'm using is based on this:
http://www.fischl.de/usbasp/
I'm am using a pre-made one bought from here:
http://www.protostack.com/blog/
This is a cool site and includes tutorials for the DIYer. I buy other supplies from here as well. One issue is the ISP connector. I use a 10 pin header which also supplies power from USB to the circuit being programmed. You might need an adapter cable to the ISP connector you are using. The signals are the same just arranged differently.

-MH