E681 to drive dumb LED string

**phillikl** · 08-04-2012, 10:12 AM

Good Day,

So had a brain fart when buying pixels, ended up with 10 sets of dummies. Thinking that my E681 will not drive strings, thought of breaking out the ol' firegod outta the attic; then had an idea! Buy a few ws2801's and drive the strings individually. After reading 9834289723449872 post in various other places i have ended up with a migraine! So thought I would bring it to the experts! Anyone ever try this? Topology really doesn't matter, just want "FLASHY"!

Thanks for the help!

Kendall

~We hit ourselves in the head with a hammer because it feels sooo good when we stop. Someone TAKE this HAMMER!

**Barnabybear** · 08-04-2012, 01:50 PM

The link to the post will not work for me, so I cant comment on that. The E68x will output dmx so that gives you lots of options. The main question is what idealy would you like to do with these? What voltage are they? How many on a string (sets of 50 in trees or 8 to 10s on arches)? Can you link the spec for the lights or do you know the current draw?

**budude** · 08-04-2012, 01:59 PM

lol... not a post - he meant he read 9,834,289,723,449,872 posts (I'm guessing it's a few less though...).

But - to be honest I read this a couple times and I'm not 100% of the question... You have dumb strings and a FireGod and decided that wouldn't work? And then bought some WS2801 chips and want to convert the dumb strings to smart pixel strings? That would not really be a viable option if I understood things correctly - it would be cheaper just to get some 2801 strings already built. I'm guessing though that a DCSSR could be made to work with the FireGod with some modification. Another option would be to get a Ren Simple controller and some DCSSRs (diyledexpress.com is a good source).

**Barnabybear** · 08-04-2012, 02:28 PM

Yea, silly me. Last resort - sell on the dumb and buy Pixels.

**jaywalk101** · 08-04-2012, 02:30 PM

out of curiosity.... could the e68x control dumb strings? I know you can treat pixels as dumb strings with grouping.. but I know that Brian and others are outputting pure DMX as well.. so could it be possible?

**chelmuth** · 08-04-2012, 02:34 PM

no the e68x's will not controll dumb strings without another controller involved and accepting DMX output from the e68x..

**Lionking_Tx** · 08-04-2012, 02:54 PM

I wouldn't sell the dumb strings - Just get a DMX controller and put them in trees

http://www.aliexpress.com/store/prod...378111925.html

http://www.aliexpress.com/store/prod...378113147.html

**Barnabybear** · 08-04-2012, 03:01 PM

I wouldn't sell the dumb strings - Just get a DMX controller and put them in trees

They are the links I was just looking for - you will need a converter for the E681 end, but see this post or PM budude http://doityourselfchristmas.com/for...-DMX-converter.

**phillikl** · 08-04-2012, 03:07 PM

Sorry for the confusion... Took a nap and refreshed now.

RGB Strings:
50 LED's per string
5VDC
20ma working
12W
-About to meter the string to get a better idea of what amperage these are pulling.

I do have a couple firegod systems, but not going to use them, want to stick with the E681. I don't want to individualize each pixel (each LED with its own ws2801), I was thinking of pixelizing each string of 50 (ws2801 with npn switch for high current) (or ws2801 for a cut group of 25, 15, 10 etc).

Ideally I could just run a single ws2801 at the beginning of the string and all LEDs would light the same color, controlled by the E681; however this chip isn't designed to pull that much current and would make smoke.

In reality I may be able to get 6-10 leds to drive off the chip and I could use the LEDs to make arches, mini trees, ball of glow, etc. Was just curious to see if anyone has attempted this before I bought some ws2801 to bench test or if a better idea was out there.

Thanks for the assist!

~Kendall

**budude** · 08-04-2012, 03:17 PM

Ahh - that makes more sense then... 5v/12W = 2.4A or 800mA/color/string - but that equates to 16mA per LED, not 20mA but I'm guess that's probably a cut/paste issue with the specs posted which is pretty common. If 20mA, then you're looking at 1A/color/string. You could probably use a 2801 to front-end a DCSSR type output (MOSFETs) - I've seen this done in a few places before. I've tossed around making a pixel chip based DCSSR before but not sure if there would be a lot of interest.