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E682 and dumb strings


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I am planning on using smart strips with the E682

I was also thinking that it would be nice to use some dumb strips for certain things where i dont need control of all the pixels. Rigt now i use a LOR DC controller

i was thinking it shouldnt be hard and probably already available a WS2811 driver that i could connect to a dumb strip and then simply use one or multiple dumb strips on a 682

is something like that available or is there something else i could / should do to make this easier?

thanks

Mike

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I didn't think these guys can help.

Anyone have any actual pictures for this so called "thingumajig"?

I too am interested in this answer.

Edited by dknahoolewa
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nothing to do with DMX

smart strips are essentially a combination of a driver chip (ie WS2811) and LED's

my thought is to use a dumb strip and instead of having a driver for one LED drive a strip from it

thinking about it i may go and check the data sheet on the 2811 and see what i can come up with

if anyone has doen soemthing like this or knows something that is available i would be interested

thanks

Mike

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I am planning on using smart strips with the E682

I was also thinking that it would be nice to use some dumb strips for certain things where i dont need control of all the pixels. Rigt now i use a LOR DC controller

i was thinking it shouldnt be hard and probably already available a WS2811 driver that i could connect to a dumb strip and then simply use one or multiple dumb strips on a 682

is something like that available or is there something else i could / should do to make this easier?

thanks

Mike

A WS2811 is a smart strip and cannot be used as a dumb strip.You need to have a dumb strip controller to use on Dumb strip's , the E682 is a smart strip controller that used E1.31 to configure it. If you need more help message me and tell me EXACTLY what you want to accomplish and your facebook ID if you have one.

I didn't think these guys can help.

Anyone have any actual pictures for this so called "thingumajig"?

I too am interested in this answer.

Contact me as well if you need any help, glad to help anyone needing it.

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A WS2811 is a smart strip and cannot be used as a dumb strip.You need to have a dumb strip controller to use on Dumb strip's , the E682 is a smart strip controller that used E1.31 to configure it. If you need more help message me and tell me EXACTLY what you want to accomplish and your facebook ID if you have one.

Contact me as well if you need any help, glad to help anyone needing it.

Actually a 'WS2811 smart strip' cosnists of a combination of a WS2811 driver chip and a dumb RGB LED (actually 3 separate LED's R,G and B). The E682 uses SPI to talk to the first WS2811 which in turn talks to the next one in line

What i am thinking about is to take dumb strips and make them smart by adding the driver chip.

Only reason because sometimes there simply is no need to address every pixel but i still want to use them as RGB. the LOR DC controller is an option but it gets expensive quickly asyou can only drive 5 of them

in the end it may not be worth the cost difference and i see that on the programming side you can group them. Not sure what that does to the max number of pixels you can use on a controller though

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Mike, you are correct. A "WS2811" is an RGB Decoder / LED driver chip. It has three incoming connections - two for the supply, and a data input. The chip receives data bits serially from a suitable driver (such as the E682). The chip takes the first 24 bits out of the signal, and sends the remainder of the bits out of the "output" connection for the next WS2811. The 24 bits that it uses, represent the light level for each of the three colours (R, G and B). So in theory, yes you can do as you suggest. However, you would have to make sure that the WS2811 could supply sufficient power to drive your led strip, otherwise you will need to design a transistor output driver for it, to increase the available current.

Regards,

Alan.

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Alan

yes that would be the only issue. I was wondering if someone already went down this route and built this.

one question regarding pixels

if you group say a string of 50 pixels into one what happens to the number of usable pixels on the E682. Are you using one or 50 ?

Mike

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There is a 2811 to DC control board being developed for the DIY community over at ACL, but its still early days. This is what you are talking about as this will then give you the ability to add a DC board within the same ouput as a 2811 strip or string.

Grouping will allow a string or strip of smart pixels to be divided up into different numbers of channels so to reduce the amount of channels the software sees. You can create a group of 50 and this will effectively turn a string of 50 into a dumb string where it is only controlled by 3 channels.

The ws2811 is in fact all smart, some of these are grouped into 3 LEDs, but all the LEDs are driven by a 2811 which is a constant current driver. A dumb strip is voltage dependant so any voltage drop effects the light output to some degree, where with constant current you can get away with 2 volts or even 3 volts with 12vdc before you actually start seeing a difference in light output. But because you have 3 LEDs in series doesnt mean any of those are dumb, the LEDs are grouped in 3s so 12VDC can be used which is far better for current requirements and suffers less from voltage drop.

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If you group a string of pixels into one, then it only uses a single pixel out of the total number that the E682 can control. If you need a long distance to the first pixel, you may need to use extra pixels to regenerate the data signal. These extra pixels can also be configured on the E682 as "extras" (I can't remember the correct name). These are specified separately and are not lit and do not count towards your useable pixels either.

Regards,

Alan.

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There is a 2811 to DC control board being developed for the DIY community over at ACL, but its still early days. This is what you are talking about as this will then give you the ability to add a DC board within the same ouput as a 2811 strip or string.

Grouping will allow a string or strip of smart pixels to be divided up into different numbers of channels so to reduce the amount of channels the software sees. You can create a group of 50 and this will effectively turn a string of 50 into a dumb string where it is only controlled by 3 channels.

The ws2811 is in fact all smart, some of these are grouped into 3 LEDs, but all the LEDs are driven by a 2811 which is a constant current driver. A dumb strip is voltage dependant so any voltage drop effects the light output to some degree, where with constant current you can get away with 2 volts or even 3 volts with 12vdc before you actually start seeing a difference in light output. But because you have 3 LEDs in series doesnt mean any of those are dumb, the LEDs are grouped in 3s so 12VDC can be used which is far better for current requirements and suffers less from voltage drop.

thanks. found the information at ACL. will follow that to see where it goes. Exactly what i was looking for

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Ray Wu offers a 2811 chip driving 12 leds, but it's 24v and circular: http://www.aliexpress.com/store/product/non-waterproof-DC24V-WS2811-pixel-module-with-12pcs-5050-RGB-SMD-LED-85mm-diameter-pcb-20pcs/701799_701852699.html

I'd like to see the same thing in a linear version for some of the designs I'd like to do.

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