The Pixels Have Arrived! [Archive] - Do It Yourself Christmas Forums

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JEC

09-24-2007, 01:24 PM

Not to spend the chickens before they've hatched, but...

An hour or two ago the FedEx fairy delivered my first 30 color-changing pixels from the overseas manufacturer.

At first glance, they look very well done.

Later this morning I'll do more testing and post photos, etc.

I received a private message a few days ago asking if I had any for-profit intentions regarding this project.

As I mentioned in the longer thread below, PIC source code + schematics for everything are posted in a dark corner of my website (www.response-box.com/rgblights/).

Someone handy at designing PCBs could fairly easily copy what I've done so far. If you want to take my circuitry & code and build your own system, have at it! What I've posted thus far is stable, but by no means perfect.

A few years ago, I would have ordered the raw circuit boards and components, then spent a few hours each night assembling them slowly by hand.

Unfortunately, current demands on my time are too great. It makes more sense for me to outsource the entire project.

I thought that pre-assembled circuit boards would be valuable to some folks on these forums.

Right now I think I'm safe in offering the pixels at $9.20 each + shipping. I don't get a break from the factory below several thousand units, so that's a fairly firm number regardless of quantity. You provide stable DMX and a stiff +12v power supply.

Yes, that's a tiny bit more than I'm paying the factory. But we're talking about something assembled, tested and guaranteed not to be dead on arrival.

If you feel you're getting a good value in exchange for the price, great!

Once I place the order, turn time is 20 - 30 days.

John

JEC

09-24-2007, 02:07 PM

Picture attached.

A Marchini

09-24-2007, 06:10 PM

I apologize if I've offended anyone by any apparent for-profitness of this endeavor. That's certainly not the intention.

John

I personally think that it is still sort of do-it-yourself, if software is something that is flexible. Just because I don't want to solder up my own boards doesn't make the protocol I use any less "done myself".
A building block , is a building block.

JEC, If you can make the changes for bi-directional communication and control, I am interested. I would not be using DMX.
Tony

Jeff Millard

09-24-2007, 06:28 PM

John,
Did you have them flip the LEDs to the back on any of them to see if it was more desirable than for them to be lower than the RJ 45 jacks?

Wayne James used a spacer on the LEDs used in his multifunction tester. They stand the LEDs off the board in many lengths. I wonder if that would settle any dispersion problems that might occur from the height of the parts.

This is a very nice unit. If you're wondering about interest in a co-op... If there is a possibility that it could be added to the Vixen add-ins and could easily be programmed (and not just with DMX) I would be interested in joining in a big batch order of them... Say 50 or so if you can get the price under $10 each.

Jeff

JEC

09-24-2007, 07:17 PM

JEC, If you can make the changes for bi-directional communication and control, I am interested. I would not be using DMX.
Tony

Tony - take a look a the attached schematic and board layout. I think I've made the bi-directional control easy to use if needed. The two pair of solder pads (about the size of 0805 resistors) are in the lower left corner of the PCB.

JEC

09-24-2007, 07:59 PM

Did you have them flip the LEDs to the back on any of them to see if it was more desirable than for them to be lower than the RJ 45 jacks?

No, none of these have been reversed.

I've attached three pictures.

I took a clear plastic container I had lying around for these pictures. I cut a large strip of heavy Apollog diffusion gell and formed it into a cylinder. Then, I put the gel inside the plastic container.

The container is about 10" tall and 5" across.

The pictures are black and white because the intensity is easier to read.

You can see that it takes an inch or two for the LED output to really kick in.

However, I'm not seeing a significant difference between the side of the enclosure 'blocked' by the CAT5 connector and the side which is freely available.

I may be able to get some video clips later on.

And yes, we're under $10 per pixel.

JEC

09-24-2007, 08:07 PM

Two more pictures.

JEC

09-24-2007, 08:48 PM

If there is a possibility that it could be added to the Vixen add-ins and could easily be programmed (and not just with DMX) I would be interested in joining in a big batch order of them...

To be honest I've never used Vixen. Though I have heard some great things about the program and its developers.

For what it's worth, my firmware could be modified to accept nearly any baud rate and / or communication protocol.

One advantage of DMX is its fairly high data density. At full speed, a packet of 512 bytes can be transmitted 44 times per second.

The pixel firmware can keep up with this, even if your eye can't.

22 Hz strobing is very shimmery.

Also, the pixel circuit board includes a programming header, allowing the firmware to be changed and tweaked as needed.

A Marchini

09-25-2007, 12:29 PM

JEC

09-25-2007, 01:29 PM

A Marchini

09-25-2007, 05:55 PM

To be honest I've never used Vixen. Though I have heard some great things about the program and its developers.

For the price of a USB to DMX output converter you could try it out. I don't remember which model of converter you are using.

I have an Enttec Open USB Pro interface that I bought in December 2005.
I believe there is a vixen plugin for that. So you could play with vixen in about the time to download and install it . If you have a PC that is. I haven't checked in to see what the Mono project is doing and how much of the Vixen software it can almost execute now.

Hey, if you are looking at numbers, I am still interested in 10 of those modules (my wife may not be, but I am).

T.

JEC

09-27-2007, 12:49 AM

I just posted a test video to YouTube.

This afternoon I programmed 19 of the pixels to sequential DMX addresses.

Then, I threw together some quick DMX-transmitting code on a protoboard. I used an 18F4550 at 20 MHz because that's what I had lying around.

The pixels are connected together with 1' RJ-45 patch cables. I'm using a bench power supply for testing, and from time to time you'll see the voltage and current display.

It's important that the +12v supply be solid! Early tests with a linear +12v, 300 mA supply were disappointing.

You'll see two effects. The first is a flame flicker. Each pixel has a discretely random rise and decay time, and the effect is being generated in real time at about 30 Hz.

The second effect is a red / green twinkle, also generated in real time.

I'm overall very happy with this batch of pixels. Apologies for the video quality - my camera isn't the best.

YouTube Link:

<object> <param> </param> <embed src="http://www.youtube.com/v/FF1YUCV_JAw" type="application/x-shockwave-flash" width="425" height="350"> </embed> </object>

And in plain text:

http://www.youtube.com/watch?v=FF1YUCV_JAw

A Marchini

09-27-2007, 12:39 PM

I just posted a test video to YouTube.

This afternoon I programmed 19 of the pixels to sequential DMX addresses.

Then, I threw together some quick DMX-transmitting code on a protoboard. I used an 18F4550 at 20 MHz because that's what I had lying around.

So, just for fun, you turned a pic into a DMX controller. Why didn't you control it from your computer? Or is the self controlled DMX strings part of the project?

Just curoius. I know that the oportunity to load up control sequences into an autonomous controller has been bandied about on the site from time to time. Of course people want to dump .Vix files into the controller so that they can setup using vixen.

Tony

cmurray

09-27-2007, 02:47 PM

That does it.
Count me in for a full string of 30.
Don't know how I am going to pay for them.
Don't even know where I am going to put them.

Just got to have them.

JOel

JEC

09-27-2007, 03:23 PM

So, just for fun, you turned a pic into a DMX controller. Why didn't you control it from your computer? Or is the self controlled DMX strings part of the project?

Just curoius. I know that the oportunity to load up control sequences into an autonomous controller has been bandied about on the site from time to time. Of course people want to dump .Vix files into the controller so that they can setup using vixen.

When the only tool you have is a hammer... :)

Yes, the end goal is to have everything be self contained. Mostly because I don't have a PC to dedicate to the project every night, and partly because it doesn't take 2.whatever GHz and a screaming loud fan to push DMX down the wire.

The '4550 was handy and it has enough ram (768 bytes) to do the math I need.

Plus, I can't program a PC to save my life.

But the embedded stuff sometimes seems to write itself.

I'm also working on a control surface & display which will allow the effect engine parameters to be tweaked in real time. That way, it can either run stand-alone effects for predetermined time period or be driven live by a person.

At this point, I haven't considered synchronizing with a soundtrack, etc.

John

JEC

09-27-2007, 04:04 PM

That does it.
Count me in for a full string of 30.
Don't know how I am going to pay for them.
Don't even know where I am going to put them.

Just got to have them.

JOel

Here you go:

http://www.christmasinshirley.com/forum/viewtopic.php?t=671

JEC

09-27-2007, 04:25 PM

Just curoius. I know that the oportunity to load up control sequences into an autonomous controller has been bandied about on the site from time to time. Of course people want to dump .Vix files into the controller so that they can setup using vixen.

Tony

It shouldn't be too difficult to build one of these. Is the .Vix file difficult to parse? I could imagine a little standalone board containing an SD/MMC card, a processor, a couple serial ports and a parallel port or two being very easy and inexpensive to create.

MP3 decoder chips are inexpensive and easy to use. So the board could have a pair of line-level audio outputs as well.

Hmmmmm.

P. Short

09-27-2007, 05:13 PM

It's easy to parse.

--

Phil

klanger

09-27-2007, 06:56 PM

Jeff Millard

09-27-2007, 08:15 PM

Sorry to get off topic here but, Kevin... I just love your SIG!!!! :lol:
jeff

klanger

09-27-2007, 09:28 PM

Sorry to get off topic here but, Kevin... I just love your SIG!!!! :lol:
jeff

Thanks to Wayne and my son.lol :D

P. Short

09-29-2007, 12:18 PM

JEC

09-29-2007, 06:32 PM

The schematic for this board over in the coop thread shows the base resistors R1-R3 as being 100 Ohms. Assuming that this is not just a documentation error, I think that they should be increased in value to around 1K Ohm, or more.

--

Phil

Thanks for catching that. Yes, they are 1K resistors and I've update the PDF file in the co-op area to reflect it.

cmurray

10-02-2007, 12:31 AM

Its de ju vue all over again.:shock:

I think I was in the same position with renard last year at this time.

So I just need to verify a few things before I dive blindly headlong into this project.

1a Each pixel is one DMX device.
1b DMX is limited to 32 devices per string(a DMX standard)
1c A DMX splitter would allow an additional 32 devices.
2 One pixel will use 3 channels.
3a You need a DMX USB Pro from Enttec
3b Will the Open DMX USB work?
3C Will anybody write a serial communication adapter THIS YEAR?
4a I will need a 5 pin male XLR to create a custom cable that will combine the DMX signal and 6amps @ 12v into a cat5 cable.
4b I will need a 100ohm 1/2watt resistor to terminate the last pixel.
5a Vixen now supports both the Enttec Open and Pro adapters.
5b The RGBLED Addin already has some color blending capabilities Just no way to see it one you have created it.
5c Worst case scenario could I just select a DMX output plugin and set the values for the RGB channels and hope for the best(thats going to take a lot of imagination or a good color blending program)

I already know I am going to get them. Now I am just trying to talk myself into it.

JOel

JEC

10-02-2007, 09:04 AM

1a Each pixel is one DMX device.

Yes.

1b DMX is limited to 32 devices per string(a DMX standard)

The limitation has more to do with the type of RS-485 receiver chip used and how it 'loads' the line. I've seen chips which allow up to 256 devices on one chain, but in this case, stick to 32.

1c A DMX splitter would allow an additional 32 devices.

Yes.

2 One pixel will use 3 channels.

Yes.

3a You need a DMX USB Pro from Enttec

Probably not.

But that's what I have. I specifically didn't buy the Open design because it relied on the computer to generate each frame of DMX. My computer was busy doing other things and I didn't want to bog it down. The Pro design can accept a frame of data and repeat it forever, until a new packet comes down the USB bus.

The Open system rolls over and dies if it's not continually updated by the PC.

I've never tested the Pro with Vixen, but I'm told there's a plug-in being worked one.

I also build custom pattern generator circuit boards based on PIC microcontrollers. If anyone's interested, I can post some source code.

3b Will the Open DMX USB work?

Yes. So long as the output conforms to the DMX timing specs, *any* DMX source can be used. Hooray for international standards!

3C Will anybody write a serial communication adapter THIS YEAR?

Maybe. I probably won't have time. Fortunately, each pixel contains a programming header, which I've already tested successfully.

You provide +12V and ground to the RJ-45 jack and clock, data, ground and Vpp to the programming header. I use the MeLabs serial programmer (melabs.com) but anything should work. The target chip is a 16F688.

Also, I connected the RS-485 transeiver to the PIC's on-board USART. So by changing the receive registers in software, nearly any standard baud rate could be used.

4a I will need a 5 pin male XLR to create a custom cable that will combine the DMX signal and 6amps @ 12v into a cat5 cable.

Yes. The pinout you need is posted on the most recent 'group buy' thread in the co-op forum.

4b I will need a 100ohm 1/2watt resistor to terminate the last pixel.

Yes. The signal gets wonky if it's not terminated properly. For a good time, take a look at the signal with a 'scope.

5a Vixen now supports both the Enttec Open and Pro adapters.

?? Don't know.

5b The RGBLED Addin already has some color blending capabilities Just no way to see it one you have created it.

?? Don't know.

Here's one other thing. I chose these particular LEDs because of their high light output for individual colors. This means that if you want white, you won't find it at [255 255 255]. You'll need to experiment a bit. White is still there, but it's not going to be exactly what the color picker says.

5c Worst case scenario could I just select a DMX output plugin and set the values for the RGB channels and hope for the best(thats going to take a lot of imagination or a good color blending program)

Yes. It's not the fastest way to do things, but you'll still have complete control over the output.

I already know I am going to get them. Now I am just trying to talk myself into it.

Decisions like this are *always* emotional; the justification by logic comes much later. *grin*

John

DynamoBen

10-02-2007, 11:06 AM

3a You need a DMX USB Pro from Enttec

In response to the Open relying on the PC, I've had my Open for two years (built it myself). I've used it for theatrical shows, Halloween displays, and DMX development. I have never had an issue. You would need a pretty slow PC doing a lot of processing before you would see issues with the Open. While the Pro is great the Open will work fine in this application, at $35 (if you build it yourself) you can’t beat the price.

3b Will the Open DMX USB work?

Should work fine. DMX is DMX, doesn’t matter what the source is.

4b I will need a 100ohm 1/2watt resistor to terminate the last pixel.

I would suggest a 110-120 ohm resistor.

5a Vixen now supports both the Enttec Open and Pro adapters.

As of Beta2, Vixen only supports the Open. There is a plug-in that is being tested for the Pro but has yet to be released. Stay tuned…

cmurray

10-02-2007, 03:55 PM

Thanks your your answers John and Ben.
That clears up a few things for me.

Ben:
You haven't read the release notes for Vixen 2.0.3.0

Added support for Enttec's DMX USB Pro module. [Thanks to RJ for his time and efforts in testing this!]

Its in there.

Found the DMX Open at siris-e for a little less than Ebay.
http://www.sirs-e.com/st/dmx-usb-c-27.html
They also offer $6.60 priority mail shipping.

Joel