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1  Using Arduino / LEDs and Multiplexing / Re: Building my own ws2801 string on: April 06, 2013, 07:53:13 pm
While these aren't RGB pixels, the process is the same for any panelized design I create, including the layout for the WS2801 + SMD RGB pixel in this thread.  I needed to make 630 bright green LED pixels and rather than buying the LilyPad pieces (https://www.sparkfun.com/products/10046) which would've cost me upwards of $500, I decided to make my own.  On a 50mmx50mm piece I can cram 23 of them: a grid of 7x3 plus two extra to fill the rest of the board.

Production of boards was $30 + $5 shipping.  LEDs and resistors just over $200.  My time: priceless.  smiley

Here's me cutting a single board into pieces, takes me a little over 2 minutes each (I already trimmed off the extra two that are along the top edge of each board).  I should point out that these are 0.8mm FR4 boards, however the WS2801 pixels I created above were done on 2mm FR4 boards.  Cutting is just a bit slower for those.



Sorry for the delayed reply, I just moved to my first (owned) home so I've been slammed the past few weeks. That's an awesome video! I have a dremmel on my wish list, but I think that sort of cutting may be out of my level until I get some better gear (and experience). I could probably order a board pre cut tho.

You had mentioned bending the LED's using the module you have.  
Quote
Like I said, you could just take a regular 3mm through hole LED, bend the bottom 3-5mm of the legs at a 90 degree angle and solder that to the boards I created.
Do you still have a few spare of these available? If I could use this technique to piece together a small 4 or 5 string light, I'd have the confidence to order all the rest of the parts I'll need. (part of my problem is I want my boss to pay for the bulk order once I know for sure what I'm doing, this is a team morale project:p) I would  certainly be willing to pay for the parts, I just don't need the whole gambit.

2  Using Arduino / LEDs and Multiplexing / Re: Building my own ws2801 string on: March 20, 2013, 06:44:12 pm
Now for some even more basic questions. How did you go about creating those boards? I've heard (and seen you guys) talk about Eagle. Do you just load up the sketch in eagle and then have someone fabricate the parts? How expensive is that normally? I assume to get them down to $1 a piece, it would have to be pretty cheap or did you get some bulk discount?

You mentioned putting the LED behind the map, were you thinking of the light shining through the paper or something else? Super dumb question, but I shouldnt have any problems with conductivity when plugging a LED through the paper and then posterboard before connecting to the chip should I?
3  Using Arduino / LEDs and Multiplexing / Re: Building my own ws2801 string on: March 20, 2013, 09:38:15 am
You really want to keep the LED close to the IC.  Running long wires between them can lead to issues.  You could use regular through hole LEDs with this if you change the layout to allow for the legs to go through, or you can bend the legs and solder them as if they're SMD parts, just on the surface of the board instead of through it.

On the other hand, having SMD lights like I did means you can put the LED behind the map without needing to poke a hole.  Might be nicer ...

I see. Thanks for setting me straight on the LEDs being wired at a distance vs closer to the actual chip. My first vision of this project involved lots of TCL5940 but I would still end up running the LEDs 2-5 feet away from the chip.

You mention being able to put the LED behind the map. Do you mean put it behind the map and have the light shine through? I hadnt thought of that, but it could potentially work, however I do have like 12 pins to put in florida so even on a 5 foot map I need a bit more standout per pixel.

Something like this http://www.ebay.com/itm/370729430086, (in a ws2801 version) may work for me, I could run the LED through the paper, stick it into the chip on the backside of the board, and then connect each chip together. Seems kinda clunky tho, maybe I'll have to cut the hole in the map :/

Or this looks close too http://www.freetronics.com/products/rgb-led-module#.UUngu6LVD2s but 10 per LED seems kinda steep.
 
4  Using Arduino / LEDs and Multiplexing / Re: Light Flow Android on: March 19, 2013, 07:55:45 pm
Great project idea! Keep us posted!
5  Using Arduino / LEDs and Multiplexing / Re: Building my own ws2801 string on: March 19, 2013, 07:43:01 pm
Awesome information so far in this thread! I feel like I'm starting to have a better understanding of what I'll need to do, but since we're mostly talking about SMD I still have some gaps.

In order to have my "loose" pixels, I'd need to have all of these parts wedged into a small area. I could put the chips on a breadboard though, with the resistors and capacitor and just plug each long LED wire into the breadboard :/

Or I guess I could build something like you've shown here but instead of connecting the LEDs directly to the chip, I'd run them via a wire for each leg of the LED.  I only need about 50 RGB LEDs so four or five of these should do the trick.

Sorry to ramble on, hoping my random thoughts will inspire someone to set me straight :p I'm pretty new at this so I apologize if my questions aren't up to par :p
6  Using Arduino / LEDs and Multiplexing / Building my own ws2801 string on: March 17, 2013, 10:18:23 pm
So I have this map project that I'm working on and I bought a prebuilt string of ws2801 LEDs. So far the project is going great and I'll be done with the prototype shortly, but in an effort to build a more svelte end result, I'd like to look into building my own string.  To explain, the prebuilt strings come with bulky cases, I need something that I can stick through my map, and do the wiring on the back side of the board(prob posterboard). This will allow me to place more LEDs in a small area and damages less of the map for removal (no big hole, just the LED legs).  I'm thinking the legs will come through, I'll solder them to some wire and run it over to a breadboard with the chip attached and linking back out to the next led.

Should I just buy a bunch of ws2801, http://www.aliexpress.com/item/Free-Shipping-100-PCS-LOT-X-Original-WS2801SO-WS2801-SOP/666372104.html, some RGB leds and let my imagination go wild? Is there anything I should be concerned with? I assume I need resistors? Common cathode or anode? Is the size of the chips going to give me problems, they seem small.

Here is the data sheet http://www.adafruit.com/datasheets/WS2801.pdf
7  Using Arduino / LEDs and Multiplexing / Re: Baby steps with addressable LED strips on: March 17, 2013, 08:41:48 pm
Check out this thread I started a few weeks ago
http://arduino.cc/forum/index.php?topic=150920.15

I went from hooking it up to being able to address each one restfully over ethernet.
8  Using Arduino / LEDs and Multiplexing / Re: Simplifying control of LED 2801 square pixel on: March 09, 2013, 06:03:04 pm
For those who end up here for info some day, yes, if you want an easy way to control a ws2801 string download the adafruit library,  https://github.com/adafruit/Adafruit-WS2801-Library/blob/master/examples/strandtest/strandtest.pde run the example and easily pick up on how to control each individual LED.   This allows you to still use the standard ethernet shield for control.

Use the following to light up the pixel of your choice
Code:
      strip.setPixelColor(21,Color(0, 0, 255));
9  Using Arduino / LEDs and Multiplexing / Re: Simplifying control of LED 2801 square pixel on: March 07, 2013, 09:46:00 pm
I've gotten some great info from this topic, (and others) so I hope its okay that I necroposted. I'm starting down this path myself. Following all the great tips I can control my LEDS individually (mostly) using fastspi, but in seeing the last few posts I know I'm running up against my next obstacle soon smiley-grin

That is because the ethernet add-on that you're using is more than likely also using the SPI bus.  

.......

For my own project last year, I went the bit-bang route.  I only had two strings of 20 LEDs each.  I used the analog pins (of all things) to control the strings, A0 and A1 for one, and A2 and A3 for the other.  
Note: bit banging IS slower than SPI, so depending on how fast you plan on sending data to the LEDs, bit-banging them may not work for you.  For me it was plenty fast still.

Could you go into a bit more detail about bitbanging these pixels? Like most people, I'd like to write a function that will do most of the lifting and let me do changeLED(LED[1],'blue'); Since I'll be using the standard Ethernet shield on 13, I'll need a way to go without fastSPI. I'm hoping my project will accept http requests to turn a pixel a certain color, and then another digital out to set of an alarm (when a project needs attention) So I dont think it needs to be fast, the colors wont change rapidly and will stay solid lit.

Should I just look at a basic spi library? https://github.com/adafruit/Adafruit-WS2801-Library/blob/master/examples/strandtest/strandtest.pde I'm at work and cant check that out, but it seems close to what I'll need. I don't have the adafruit string, but I assume most 2801 will be similar

You also said
Just set everything to white first (you don't need an array for that), then cycle through the BlueLEDgroup array and turn those blue.  When you're done with that, then you can call FastSPI_LED.show() which will turn the LEDs on.
Even though I'll be moving off fastspi after your advice, I'm curious what the single command is to set the whole string white smiley

Thanks!
10  Using Arduino / LEDs and Multiplexing / Re: Hooking up basic WS2801 string on: March 07, 2013, 08:01:17 pm
For anyone interested, I ended up going with   FastSPI_LED.setDataRate(2); and it worked a lot better for this particular setup.
11  Using Arduino / LEDs and Multiplexing / Re: Hooking up basic WS2801 string on: March 04, 2013, 09:13:42 pm
I suspect the code is wrong.

I've never used FastSPI: https://code.google.com/p/fastspi/

OTOH I noticed that near the bottom of the front page it says:


Note for people using sparkfun's ws2801 led strips - you need to call FastSPI_LED.setDataRate(1) before calling init/start. The library defaults to a data rate of 0 for ws2801 strips, which is valid for the chips on the 12v strips, but not on the 5v strips (or, at least, the 12v strips that I have here) - it's too fast and you get weird random flashing occuring.


They are dancing mad now! I should have known to include FastSPI_LED.setDataRate(1), I saw that in one of KirAsh4's other posts but didn't think to add it.

Thanks a ton for the help, my next steps are going to be to learn to control each one individually then hook up the ethernet to start addressing them from there smiley I'm sure I'll have lots of questions along the way so I'll keep you informed of the progress.
12  Using Arduino / LEDs and Multiplexing / Re: Hooking up basic WS2801 string on: March 04, 2013, 01:37:37 pm
I updated the sketch to reflect pin 11 and moved the green wire over to it. I'm still getting rather eratic output from the lights. See below
Sorry for the low quality, was trying to rush this in during lunch.  There are 25 lights in the strand, only the first few are lighting up in this example, but in various testing I have seen the whole string power on.

https://dl.dropbox.com/u/4099132/New%20Folder/VID_20130304_133219.mp4
13  Using Arduino / LEDs and Multiplexing / Re: Hooking up basic WS2801 string on: March 03, 2013, 08:34:08 pm
Sorry for the delay.

Documentation says
http://www.insomnia.org/led/documentation/rgbpxws2801.html
Red is +5v, Green is clock, Yellow is data, and blue or grey is ground. The input side is the side with the IC.

I've connected it up based on this spec, but all I really get is the first LED lit up blue. This is green to 13 and yellow to 4, to match the code.

If I switch Yellow and green, I get various lights lit up but it does not follow the pattern designated in the code. I get eratic flashing. If i remove the data from out 4, I still have various lights lit up. I've included a few shots to help debug whether maybe the lines are done wrong.

As for the code, I'm using Pin 4 as specified in FastSPI example. I commented out the other modes and just ran   FastSPI_LED.setChipset(CFastSPI_LED::SPI_WS2801);. I'm hooking clock into pin 13 and digital into 4.

Input

Output

My connection

Do these solders look okay?




14  Using Arduino / LEDs and Multiplexing / Re: Hooking up basic WS2801 string on: February 28, 2013, 12:32:44 pm
Hmm. This map will have about 50 LED to be exact and I plan to keep them at a solid color to indicate account status. Ideally I could leave this plugged in forever, but if I need to switch out off I can. You said I need 5-6 Amps, does that mean the v5 won't do it?

Power supply volts is usually independent of amps. The 5 volts aren't negotiable, the amps are.

I'd get at least 6A if you're going to leave it on 24/7. 8A would be even better.

Make sure it's a 'regulated' supply, something like this: http://www.ebay.com/itm/110741575602

(nb. randomly chosen eBay item...)


hm, I'll probably come back to you on this one. I should be able to drive this from my PC until I know enough to try and attach an external supply.  Thanks for the recommendation!

Tonight, i'll cut of the SM connector, hook it to Arduino and let FastSPI fly.
thanks again
15  Using Arduino / LEDs and Multiplexing / Re: Hooking up basic WS2801 string on: February 28, 2013, 10:59:24 am
Note that strings like this can require a surprising amount of current. If you switch all LEDs on simultaneously that's 60*3*0.02 = 3.6 Amps. You need at least a 4 Amp power supply, preferably 6 Amps or more if you plan to switch it on for hours at a time (although you probably won't have it all white very often in practice so 5-6 Amps is probably OK).

Hmm. This map will have about 50 LED to be exact and I plan to keep them at a solid color to indicate account status. Ideally I could leave this plugged in forever, but if I need to switch out off I can. You said I need 5-6 Amps, does that mean the v5 won't do it?
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