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That makes we want to put a scope on the end of the line and see what's happening to the waveform.  There are 2 variables for 2811 timing, the width of the bit cell, and the points in the bit cell where the data line transitions from 1 to 0, early in the cell for a 0, late in the cell for a 1.  If the 1-0 transitions occur near the edges of the bit cell then that would allow for a wider range of speeds to be accepted by the pixel with the tradeoff being that you are having to send higher frequency pulses down the line, and IIRC that's what's recommended in the 2811 data sheet, something like transitioning at 20% for a 0 and 80% for a 1.    Positioning the 1-0 transitions nearer the center of the bit cell reduces the allowable timing variation but also reduces the bandwidth requirement on the line.  By slowing down the data rate you are pushing the 1-0 transition for a 0 bit closer to the time when the data is sampled by the chip.  In theory, if the code is set to divide the bit cell into 5 increments, you could operate anywhere from about 350kbps to about 1200kbps.  If you've experimented with it, is this about the speed range that you can operate at? 


Unfortunatly im not as talented as you when it comes to the code and data so i cant answer very well. The J1SYS have a data setting which appears to be a number and not an actual refresh rate as persay (it may be 3x the data rate). So with the ECG controllers its 3500 standard speed for normal short cable connections but this number lowers the longer the distnace is, so for me at 10 metres 3500 did not work at all, even at 3000 i still had no action, it wasnt until i set the speed to 2000 that i got a stable output to the 2811, ive tried it down to about 1600 below that it would stay on all white. So there is definetly a relationship between the data speed and the distance. This may be because of the reset bit which is given more time so the chip can see this amongst the lower signal strength and possible interferance, but thats just an uneducated guess. But worth looking into as a possible feature for the E68x controllers.

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I have been told that the San Device is the way to go by some folks that have done this for several years one guy that lives near me used it last year and said he swear by it.



And i bet those users have only ever used a sandevices, I find many swear by something who have never used or seen the other choices, which is all too common, so i wonder what they base their advice on. I based my advice on actually using both types in my display over 2 years. In the end they will both achieve the same desired goal, If your getting in a kit form to build then the E682 will be a good value choice and im sure you will be more than happy with it.

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Saw your PM and before I amswer that, I need to add one more bit.


As much I love my SanDevices controllers, before you take the plunge, have you asked the same question over at doityourselfchristmas.com? I only ask because fasteddy is right, most of us are giving you our opinion based on our experience and a lot of us have only used one brand. But like the purchasing of a car, you can ask someone all day long "do you like your car you just bought?" in the end they have no other new cars to compare it to, and a 10 minute test drive doesn't help much. All you have is their opinion. Then you have to wonder if the person giving you the opinion has an agena in any way. The internet has changed personal interactions in so many ways. If you ask a simple question "where should I purchase some LEDs?" You get those that will say google.com.....other will say "check out my website" but rarely is it done like 20 years ago. "I use Joe Blow, he has decent prices and stands by his product, he is a good guy, there could be others, but am happy with Joe" So in the end you make an informed decision based on the experiences of others and the level of respect/trust you have for that person. Bobby wants to go with SanDevices because a guy that lives near him uses them! That is much more tangible that any of us in the forum. All of us here are pretty much random aquaintences.


That being said, yes, I went with Jim and his SanDevices, why? Here are the reasons:


1. He didn't make me feel like an idiot, even though that is what I am. Answered every lame question.

2. I liked the idea of having 16 connections (conversely, for certain applications I like the ECG-P2 with only 2 pixels strings and look forward to using them somewhere) I chose my pixels first and since they were 5V, I did not want to mess with injecting power down the line, so the more connections, the better.

3. I liked that DMX universes could be split across connections

4. 2 people that I respected very much Donny Carter and Mark Schell (and helped with my CCPixel debacle over at LSP) said they had no problems with them and would use them again.

5. At the time LSP was having trouble transferring Matrix setups from sequence to sequence (if they were existing sequences) so I needed a setup that was fast and easy to duplicate. All first pixels starting at one end going up was easy to duplicate, not even I could mess it up.


I have been a member since 2007, but, I never asked the question over at doityourselfchristmas.com. Why? Well, I was never planning on getting into the DIY RGB Pixels, all of you were nuts! I barely had enough time to do my display. I didn't want to mess with soldering and group buys and all that jazz. So i jumped in to the plug and play CCPixels and LOR forced me to find an alternative when, as a LOR employee said "maybe they will just never meet your standards." I stopped my correspondence after that statement back in July and I was strapped for time. But, with the help of Donny and Mark, I found something that worked as I envisioned, and cheaper.


My setup was easy, rectangular panels with 2" spacing. I am having trouble 100% visualizing what you wish to do and do not want to steer you in the wrong direction.


So, really, start a thread over at doityourselfchristmas.com and get some more opinions, you do have time. Download the manuals and read them and see what interface you think you might like better. I don't mind user commands, but I had to have a copy of the manual handy.


Then again, $189 for an assembled SanDevices board, hard to go wrong.

Besides, whatever you decide on, I am sure you won't stop at just one!


Good luck!


Edited by thebaronn
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Eric brings up a very good point about how the internet has changed our perceptions on things and our buying habits as well.  Fast Eddy is also correct about his usage of both controllers (SansDevices and J1Sys) and the differences between them.

I ended up choosing the J1Sys because of reading up on the forums and the differences between the two controllers.

I like the ability of the J1Sys to adjust the speeds in case of problems with distance and more importantly quite a few people that I asked about these controllers all pointed to the web based interface of the J1Sys controller being so much easier to use than the SansDevice.  It also "appears" that Ed has done a lot of thinking with his controllers as he has designed them for possible future options on the boards from the looks of them.

I am sure that the SansDevice one is a fine controller and not that bad to setup once you know how.  The fact that Bobby has somebody near him that uses the SansDevice controller makes that somewhat of a logical choice for him I would think as he can get some assistance pretty easily if he needs it.

Since I live in the middle of nowhere, I need something that I can figure out myself easily!  Although now days help is just an email or instant message away pretty much anymore.  But I am one of those who can look at something and figure it out most of the time so I am pretty sure that I could do either controller with enough coffee and my trusty hammer !!

Edited by Bill Ellick
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I chose the Sandevice because I am all about having the ability to expand later and the E682 has the 16 ports where as the P12R only has 12. I did bring up the way they both are programmed, I am not against using the code, so therefore that wasn't the deciding factor. After seeing thebaronn's display and how the E682 worked with his matrix, which is the same thing I am building.


I also had emailed Jim @ sandevice and asked a couple questions and this was his response.


The next firmware release, which should be in beta in a couple of weeks,
will improve the user interface, but it still won't be as "pretty" as the
J1SYS boards.  My boards use the Propeeller 8-core CPU, and there are
advantages and disadvantages.  This firmware will also add unicast
capability, planned for 12 universes.

One advantage of the propeller CPU is that all 16 pixel outputs can be
driven simultaneously, whereas the J1SYS board has to refresh pixel
strings in a round-robin fashion, sharing the 12 outputs between 3
hardware SPI ports.

The continuous refresh of the E682 allows for features such as 8-bit
dimming resolution of the normally 5-bit 6803 pixels by shifting the
intensity values slightly on each refresh pass.  This feature will soon be
extended into the 8-bit pixels, which will allow the implementation of
dimming curve corrections on almost all pixel types.  The E682 already
supports dimming (gamma) correction for the TLS3001 and CYT3005 12-bit

An example of a disadvantage of the propeller is limited memory conpared
to the PIC porcessors used by J1SYS.  This is one factor that forces a
somewhat simplified web interface, at least at present.

Re the data rate, it is not selectable at this point but I would offer a
few comments.  Per the paragraph above, the J1SYS boards must drive 4
pixel strings on each hardware output.  This requires that the data rate
be 4X as fast for a given refresh rate, since the J1SYS boards have to
refresh 4 strings in the time the E682 refreshes just one.  As a result of
this the data rate can be kept at a lower value, which improves
line-driving capability.

Also, data rate settings really only apply to 4-wire pixels.  The 3-wire
pixels have a specific data rate that they are designed to run at, and
while you can tweak it slightly, there is really no purpose in doing so.

I don't think you will be unhappy regardless of which way you go, but if
you buy an assembled board from me and are unhappy with it, I will take it
back and refund your money.


When I need to purchase another controller I could also purchase the P12R to try it out as well. But for the project I have decided to go with the E682 and I have purchased the assembled one. Compared to the controllers I use for my incandescent minis these Pixel controllers even assembled are half the price of my older controllers.

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@ireqs the j1sys.com website says that they are instock.



Item in stock and ready for shipment 48 hrs ARO.

Orders should include product requested, quantity, shipping mode, and complete shipping address. Orders should be placed via email to: [email protected]

We reply via email with an invoice for confirmation and payment.


@Brian000 yes you can connect multiple strings to one port

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@ireqs the j1sys.com website says that they are instock.


I must be missing something something.  Store says see ebay, Ebay store does not show any. Only shows ISP adapters.

Edited by iresq
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I must be missing something something.  Store says see ebay, Ebay store does not show any. Only shows ISP adapters.



Take a look at the attached J1SYS product matrix at the bottom of each controller type there is a direct link to the web page for each controller with ordering details



Edited by ɟɐsʇǝppʎ
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Slow your roll! Jim has a new controller! It appears to be a mini, but I like it!

Just thought I would throw that out there!



Its great to see further value added to the controller range offered to the community. I commend Jim for stepping up to the plate and offering a great valued option to the community and constantly improving his controllers.

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Take a look at the attached J1SYS product matrix at the bottom of each controller type there is a direct link to the web page for each controller with ordering details


Ah yes.  His business/marketing skills must be a little light.  A potential customer should not have to search on how to make the purchase.  What's worse is the store link directs you to ebay.  

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Ah yes.  His business/marketing skills must be a little light.  A potential customer should not have to search on how to make the purchase.  What's worse is the store link directs you to ebay.  


I think that that statement is just a little wrong in my eyes.

Each of these two (Jim - SandsDevices and Ed - J1Sys) are each working hard to give us all good products that will help with our lighting needs.  I think that they are both pretty busy with getting the actual hardware and software running for us as well as the updates as new lthings come on the market.

If you look at the two web sites you can see that Ed has quite a bit more to offer (as of right now) as far as hardware than Jim does.  Does that make either of them less worthy of our repsect.  Not at all.

I know that if I was manufacturing a product, I would certainly be more worried about it performing as it should rather than if my web page has a spelling error or link concern.  Though it is true that the sites need to have the correct information for us to make an informed decision for a purchase.

I am one who goes by what a site tells me rather than sending countless emails or phone calls since no matter who you talk too, they are certainly going to try and sell you on their product and not the competitions.


I would also think that both of these fine gentlemen are seeing the growing pains from the rapid advancement of RGB stuff in this hobby and are probably busy trying to keep up with it along with the rest of us.


My hat is off to both of them personally and I would bet that they are going to "upgrade" their sites pretty soon along with all the new things that they are coming out with.  Just need to give them a chance.


Sorry for the rant.  I'll stop there.

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