EEVblog #928 - Jaycar DMX RGB LED Lights Teardown - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: September 28, 2016, 01:03:22 am
content: Inside the cheap arse Jaycar SL3467 "Rave" DMX controlled RGB LED disco party lights scored for $1 from the dumpster sale. Did Dave get ripped off?http://www.jaycar.com.au/multicoloured-led-party-or-stage-lighting-kit-with-stand-controller/p/SL3467

author: Brumby
author_rank: Unknown
timestamp: September 28, 2016, 02:07:14 am
content: Some useful bits there - but the overall idea was not executed too well. $1 was a fair price.If you're done with the gear, I'd be interested in the lights and control unit... might be able to make something of it. Notreallyinterested in the foot controllers.Open to offers?

author: boffin
author_rank: Unknown
timestamp: September 28, 2016, 02:16:40 am
content: It's built to a price for sure, but it can still put out some serious light.On the red channel that 1st panel has a blown LED or dropper (there's 4 LEDs that look like they should be lit), and probably draws closer to 2W if they were all working. And yes, Red is generally higher efficiency.5W ea for the G and B , and you're looking at a 12W LED panel, which is probably between 80-100W incandescent bulb. four of those should put our some serious eye burning if you point them in the same direction.Should be a snap to fix it up, and get it working, and it could be handy for some things (turn your head 180 degrees to read that LED panel).Even if you just wired each panel for +12/GND, it could be useful lighting for something.

author: calexanian
author_rank: Super Contributor
timestamp: September 28, 2016, 02:22:09 am
content: There appeared to be some unsoldered joints on the control board. Wonder if thats whats causing the failure. Otherwise you basically got some scrap for a buck. Here in my area we would use that for target practice out in a field somewhere.

author: boffin
author_rank: Unknown
timestamp: September 28, 2016, 05:14:29 am
content: Quote from: calexanian on September 28, 2016, 02:22:09 amthe unsoldered joints are just the other side of the push switches. They just soldered 2 of 4 joints for speed (and cheapness)

author: pickle9000
author_rank: Super Contributor
timestamp: September 28, 2016, 06:17:57 am
content: Just for the housings I'd buy a few. Looks like an OK mounting system for the lights and it's easy enough to buy led panels that would fit in. Looks like they swivel. Would I used the rest of it? Probably not but it can always be donated to a person in need.As for Dave a buck for a teardown video? That's a no-brainer,

author: nomis
author_rank: Contributor
timestamp: September 28, 2016, 10:33:02 am
content: Note that the display actually seems to display something useful - it is just upside down in the video.I can see Addr, dISP, SLAv, which are familiar to me from other cheap ass dmx equipment...Note that the UI usually is pretty horrible though...

author: haybailes
author_rank: Newbie
timestamp: September 28, 2016, 01:18:39 pm
content: i picked some up as well from the saleand one of the funny things i saw on my was the pins going through the board some were cut but most were not pic belowalso the red leds have a patten but just have gone/blown, also pic below in a different spot from yoursi got board the other day and started putting an arduino with them for when i go camping because why notkeep an eye out onwww.tinkersprojects.comi will post on here when i make something work if i can

author: Twoflower
author_rank: Frequent Contributor
timestamp: September 28, 2016, 05:36:13 pm
content: Looking at the display I would think the DMX controller is not designed for down under. The product is meant to be sold on the other side of the world.It looks if the pins were ripped out of the connector and stuck in the faulty socket.

author: JimP
author_rank: Newbie
timestamp: September 28, 2016, 06:10:03 pm
content: Dave, while watching the video on the Jaycar LED Lights, you were showing the menu on the interface box and saying there was gobbletygook on the display. I thought this too initially, but after a few seconds I saw what is happening.When you first turned it on that it showed what looks to be "E 45", but it's actually "Sh 3" upside down. If you turn the interface box upside down, you'll notice quite a few readable words (?) on the display. At 3:55 it looks like "SLae", at 4:03 it's actually "Addr", at 4:04, it's "SLnd", at 4:06, it "Chnd". etc., etc.I don't know wexactly what they mean, but I'm sure "Addr" is address, "CHnd" is probably channel, etc.Just wanted to let you know the observation I made. Although several have likely already alerted you to it.Keep up the good job.Regards,Jim

author: jitter
author_rank: Frequent Contributor
timestamp: September 28, 2016, 06:22:07 pm
content: For me the most interesting part would be the PSU. I mean a 100 W for $1?It looks like a decent quality PSU and the caps used are Aishi. Not the most well known brand, but I've said it before on this forum, I've come to trust these Chinese caps as if they were Japanese branded ones.Most recently I tore down two LED-bulbs that had done their promised 25,000 hours. The Aishi caps sat smack in the middle of the heat and measured just fine capacity and ESR wise.So yeah, salvage the footpedal and the PSU, dump the rest.

author: tigrou
author_rank: Regular Contributor
timestamp: September 28, 2016, 08:08:19 pm
content: I'm wondering how is the DMX signal processed.Is it done entirely by the Amtel16 microcontroller ? Is a 16mhz cpu fast enough to analyse (in realtime) a 250 kbit/s signal (and also at the same time drive the LEDs) ?

author: thm_w
author_rank: Super Contributor
timestamp: September 28, 2016, 08:51:02 pm
content: Quote from: tigrou on September 28, 2016, 08:08:19 pmDMX signal, its about 40Hz, 22ms max:http://ricardo-dias.com/2013/03/29/dmx512-protocol-at-low-level/So some dead time if necessary, but its going to be handled by hardware UART so will not use much resources.There would not be much analysis, if byte = address then process, otherwise ignore it.The LEDs might take more work as its done with shift registers.

author: eamoex
author_rank: Contributor
timestamp: September 28, 2016, 09:26:12 pm
content: Love Dave's videos, but this one should not have aired. We get it: Chinese make crap. Get over it. My guess is it's too big an object for a two-minute teardown and not sophistcated enough for a full-featured teardown or even repair. I dunno, but it did not feel right.Again I usually love the videos and I don't mean to offense; I really frankly think this is hurting the blog's quality.

author: Towger
author_rank: Super Contributor
timestamp: September 28, 2016, 09:28:37 pm
content: Quote from: tigrou on September 28, 2016, 08:08:19 pmUpsidedown display: There is often an option to reverse the display direction. As with many of these cheap units they are not very intuitive and you really need to RTFM to work out all the menu options. In saying that most are the same in basic operation, but you are doing well if the manual matches the units operation 100%.Build quality: I have seen worse in cheap led disco lights. However they are not even CC driving the LEDs, even the cheapest allieexpress units are current driven these days.MCPU: Expect their refresh rate to be slow and strobe like mad when videoed. Their dimming curve to be crap and snap out at the lower end. Colour mixing to be bad and change as they are dimmed.

author: NickS
author_rank: Unknown
timestamp: September 28, 2016, 09:58:09 pm
content: Quote from: eamoex on September 28, 2016, 09:26:12 pmI'm slightly shocked that Jaycar (reputable Australian retailer) actually sold something that didn't even have a brand.They sell some cheap stuff, but it's generally got a brand of some kind on it.

author: Brumby
author_rank: Unknown
timestamp: September 29, 2016, 03:04:34 am
content: Quote from: NickS on September 28, 2016, 09:58:09 pmCertainly, price considerations would have been high on the list, but I'm not."Rave" was printed on the carry bag - and that's enough to call it having a brand. The gear itself is "branded by association".

author: EEVblog
author_rank: Unknown
timestamp: September 29, 2016, 03:16:55 am
content: Quote from: Brumby on September 29, 2016, 03:04:34 amYeah, I think this (and the other "Rave" gear) essentially has no brand. At least I haven't been able to find the OEM.Jaycar probably wouldn't have custom ordered the design of them, so likely it does exist somewhere else?

author: Vgkid
author_rank: Super Contributor
timestamp: September 29, 2016, 05:15:09 am
content: Thanks for the teardown. Those lights and PSU are still useable, along with that foot switch.

author: GabYoung92
author_rank: Regular Contributor
timestamp: September 29, 2016, 05:16:28 am
content: The most common fault on these units was that the LED's would burn out!

author: jitter
author_rank: Frequent Contributor
timestamp: September 29, 2016, 05:55:15 am
content: Quote from: eamoex on September 28, 2016, 09:26:12 pmI actually enjoyed the video, so the not airing thing is something I don't agree on and I also can't imagine why it would hurt the blog.This particular tear down subject turned out to be of low quality (aka "crap"), but that was a design decision. This was designed and built down to a price, but the same factory might be churning out stuff for the pro brands as well (the usage of A-branded semiconductors instead of Wun Hung Lo's best on the control board might be an indication of that).And not all the Chinese design and manufacture is crap, I would not have any second thoughts on using (e.g.) Mean Well PSUs despite the somewhat funny or tacky sounding name.

author: pickle9000
author_rank: Super Contributor
timestamp: September 29, 2016, 07:22:20 am
content: Hey Dave,How about a "What is crap / crusty video?". A comparison between 1970's and 80 consumer gear and modern consumer gear. How similar some of the old stuff is to modern low end products. No need to get fancy early calculator, and then one from a dollar store. Perhaps include a price or two.Building down to a price is a part of the game when production runs are high.

author: Fungus
author_rank: Super Contributor
timestamp: September 29, 2016, 08:39:33 am
content: Quote from: tigrou on September 28, 2016, 08:08:19 pmSure it is.AVR chips have hardware to receive the individual bits then set a signal when a full group of them have arrived.If it's 8 bits per byte then bytes are arriving at 32kHz. 16MHz is plenty fast enough to process that.

author: Fungus
author_rank: Super Contributor
timestamp: September 29, 2016, 08:40:52 am
content: Quote from: wilfred on September 29, 2016, 06:27:58 amYep. The Chinese are perfectly capable of making good quality stuff (everybody knows they're good at math!)If they're exporting crap it's because the round-eyes are buying it by the container-load.It's also because the round eyes aren't above exploiting people who are desperate enough to work for pennies per hour. People who live in glass houses...Quote from: eamoex on September 28, 2016, 09:26:12 pmLuckily for the rest of us, the blog isn't individually tailored for you.

author: EEVblog
author_rank: Unknown
timestamp: September 29, 2016, 09:48:58 am
content: Quote from: Fungus on September 29, 2016, 08:40:52 amExactly.And the video was as advertised, it was a teardown of a cheap Jaycar light.Didn't turn into a great video because, well, turns out there wasn't anything interesting in it, and quite frankly I couldn't have been bothered doing anything else with it like reverse engineering it or experimenting. So, meh, I just uploaded what I had. I'm guilty of uploading a fairly boring and low-ish technical quality content video, sue me, that happens. 90% of the people who rated the video thought it was ok enough, so, well, there's your answer I guess.

author: Fungus
author_rank: Super Contributor
timestamp: September 29, 2016, 10:43:13 am
content: Quote from: EEVblog on September 29, 2016, 09:48:58 amI didn't think it was bad. It's always good to see inside stuff.A good electronics designer needs to know both ends of the spectrum. You can learn just as much from aninformedteardown of "low quality" stuff as from a teardown of "high quality" stuff.The low quality stuff is still a working design.

author: eamoex
author_rank: Contributor
timestamp: September 29, 2016, 11:42:27 am
content: Quote from: Fungus on September 29, 2016, 08:40:52 amWho said it should be?Of course good stuff is also made in China, of course it's cheap to use the wordChinesethat way, I just meant that the video comes down to saying this piece of hardware is crap repeatedly, and it's a little boring after hearing it 4 times.

author: Fungus
author_rank: Super Contributor
timestamp: September 29, 2016, 12:41:56 pm
content: Quote from: eamoex on September 29, 2016, 11:42:27 amFeel free to click "STOP" and go watch something else.

author: eamoex
author_rank: Contributor
timestamp: September 29, 2016, 04:55:33 pm
content: Quote from: EEVblog on September 29, 2016, 09:48:58 amI did not thumb down the video -- but Ididbring that 10% into the thread!

author: Towger
author_rank: Super Contributor
timestamp: September 29, 2016, 08:00:11 pm
content: QuoteThe other end of the stage/disco lighting quality and complexity spectrum can be seen here, in Big Clives video:https://youtu.be/4yMHV_6SB7c

author: EEVblog
author_rank: Unknown
timestamp: September 29, 2016, 10:28:45 pm
content: Quote from: eamoex on September 29, 2016, 04:55:33 pmBTW, the 10% is generally a skewed figure anyway, as people with strong negative opinions will tend to be more liable to take action than those that have a positive or neutral position.In any case it's a very typical figure for a "meh" level video.And if I dare mention a poor quality no-name Chinese product, out of the woodwork they come.

author: Halcyon
author_rank: Unknown
timestamp: September 29, 2016, 10:33:03 pm
content: Seeing low quality products is a good way to demonstrate whatnotto do if you're designing a product or what to look out for when buying.

author: rrinker
author_rank: Super Contributor
timestamp: September 29, 2016, 11:50:16 pm
content: It's definitely worthwhile see how NOT to cut corners in a design. I also enjoyed the more off the cuff feel of this video. I don't think I'd like them all to be like this, a little post-production polish is nice, but in this one I think we saw the natural first reaction as Dave got a look at things, nothing toned down or restated, and it was a nice change. Not everything needs to be finely tuned with all mistakes edited out and carefully thought out statements inserted.

author: Brumby
author_rank: Unknown
timestamp: September 30, 2016, 01:41:47 am
content: There are a few posts that make reference to the value of a tear-down of 'cheap crap' ... which is, as I see it, understanding what is considered cheap - and the significance of that.For example:- a cheap effort on a safety earth. What it looks like and why it's bad.- Wun hung lo LEDs - and their life expectancy.... and so on.Also, even with cheap crap, there can be some examples of things done well.All in all - this tear-down may not have been of a product in the same class as a Keysight scope, but it DID provide some useful information.As to whether it will appeal to everybody's taste ... that's just a subject no blogger will waste any time over. It's just impossible.

author: jitter
author_rank: Frequent Contributor
timestamp: September 30, 2016, 04:28:42 am
content: Quote from: wilfred on September 30, 2016, 02:11:02 amJust for the fun of it!Not everything needs to be justified, and the existence of a (IMHO) reasonably successful channel dealing mostly with just this sort of cheap stuff (usually bought off eBay, AliExpress etc.) to me seems proof of it.He was linked to just a few posts back. Just when I think I've seen the most unlikely or dangerous contraptions I possibly could I tune into Big Clive's channel and find there's actually lots more...

author: NottheDan
author_rank: Frequent Contributor
timestamp: October 01, 2016, 02:34:44 pm
content: Okay, I have to ask. What is the thing with the fold-out arms on the unit? They barely spread the sockets any further apart and there's so much space left in the base unit that the sockets might as well have been mounted at the end caps with no effective difference (except that you'd have half the unit more space), so what use are they really? Just for show?And with cheap designs "down to a price" I have to agree with other commenters. Some more depth in what compromises would be acceptable and what you would cut down on if you had to design that unit would be nice.

author: Halcyon
author_rank: Unknown
timestamp: October 01, 2016, 04:11:17 pm
content: Quote from: NottheDan on October 01, 2016, 02:34:44 pmIt looks like the controller was designed to mount onto a T-stand with the LED lights fixed to either side of the fold out arms (there are screws on the LED lights with what look like corresponding holes on the bottom of the controller module and arms).

author: NottheDan
author_rank: Frequent Contributor
timestamp: October 01, 2016, 05:12:12 pm
content: Quote from: Halcyon on October 01, 2016, 04:11:17 pmAh okay. Looks pretty flimsy for that job though.

author: Brumby
author_rank: Unknown
timestamp: October 02, 2016, 02:00:07 am
content: ... a function of the price point.Just means you need to "Handle with Care" - not like roadies on a tour.

author: Halcyon
author_rank: Unknown
timestamp: October 02, 2016, 05:48:35 am
content: Quote from: NottheDan on October 01, 2016, 05:12:12 pmOh yeah, it's a piece of crap. No argument there.