EEVblog #787 - Mailbag - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: August 25, 2015, 11:25:24 am
content: More MailbagForum:SPOILERS:Zhiyun Z1-Evolution 3-axis GoPro IMU based handheld image stabiliser gimbal:http://www.zhiyun-tech.com/index.php?m=content&c=index&a=lists&catid=54http://www.skytechinnovation.com.au/Nagle Industries Glow-Tie, RGB LED Bow-Tie:http://www.nagleindustries.com/https://www.kickstarter.com/projects/nagle-industries/795935220https://www.kickstarter.com/projects/gooligumelec/wombat-a-prototyping-platform-for-raspberry-pi/descriptionRaspberry Pi Wombat Prototyping boardhttp://www.gooligum.com.au/raspberry-pi/wombat-protohttps://www.kickstarter.com/projects/gooligumelec/wombat-a-prototyping-platform-for-raspberry-pi/descriptionCasio FX-991EX Calculator with engineering notation display.http://edu.casio.com/products/cwiz/fx991ex/Hobby Creek Third Hand Tool:http://www.hobbycreek.com/shop/KVM switch teardown

author: janoc
author_rank: Super Contributor
timestamp: August 25, 2015, 01:44:35 pm
content: Dave, the third hand kit is originally a SparkFun product:https://www.sparkfun.com/products/11784They have licensed (?) the idea from someone who has described this on Instructables (the link is on the SparkFun website). The "arms" are actually lubricant hoses for machine tools (like a lathe or a mill). The large holes in the base allow you to screw in additional ones or one with a different attachment (magnifier, fan, etc). There is actually a screw under the orange tip, just "break off" the tip (it takes quite a bit of force to spring out the spherical joint, don't hesitate to unleash brute force on it!) and then you can replace the crocodile clip with something else. SparkFun has a video on their website on how to assemble these hoses - it is quite difficult!I have the SparkFun one and it certainly doesn't tip over like the one you have - the base seems to be larger a bit. You can solder on it if you hold the board using 3 of the clips, then it is pretty rigid even though clunky. I cannot imagine using it to hold probes, though, because the hoses are very "springy" and it is difficult to get them positioned accurately.

author: ornea
author_rank: Unknown
timestamp: August 25, 2015, 01:54:07 pm
content: FYINot sure if it should be but this Mailbag video is not on the main page athttp://www.eevblog.com/... update, it is now.Not up with exactly what open source hardware is about but I was not expecting to see patent pending on an Open Source Device

author: firewalker
author_rank: Super Contributor
timestamp: August 25, 2015, 01:55:47 pm
content: I have seen machinist using soap water hoses as third hand for decades. Mainly for mounting magnifying lenses and lights.Alexander.

author: hikariuk
author_rank: Unknown
timestamp: August 25, 2015, 02:48:40 pm
content: If you'd watched the "I Dream Of Wires" documentary you had on one of your earlier mailbags you'd know Muff Wiggler :pI am happy to say I get the Shermer Illinois reference...although this shows my age. I think I may need to re-watch the relevant film now (fortunately I have it on BluRay).

author: Harrkev
author_rank: Contributor
timestamp: August 25, 2015, 02:53:55 pm
content: Sorry Dave, but I can't take a man seriously if he doesn't like peanut butter and chocolate together. It makes me question all of his other decisions.

author: Fungus
author_rank: Super Contributor
timestamp: August 25, 2015, 02:57:53 pm
content: Those calculators are way cheap, $26 on eBay with free shipping. I was expecting more than that. I might have to get one, my current calculator sucks. OTOH you're right, VPAM sucks for basic, quick calculations.PS: Calculator review and you didn't calculate '69!' ??PPS:Aluminiumfor a counterweight on a stabilizing arm? Fail. I'd glue some nuts and bolts to it.

author: steve30
author_rank: Frequent Contributor
timestamp: August 25, 2015, 03:06:18 pm
content: I noticed the bow tie said 'Pending Patent Pending'. Presumably that might be a joke to mean that it isnotpatent pending.The calculator looks good, but why does it use that Chinese style serif font? Looks weird.

author: max666
author_rank: Frequent Contributor
timestamp: August 25, 2015, 03:32:52 pm
content: That ServSwitch KVM switch teardown was much more interesting than I expected. That's to no small part due to your excellent teardown skills, Dave.I always have my Ti-92 Plus in arms reach, and the Infix Notation certainly has it's pros and cons. I prefer it for more complex calculations though.

author: adrian
author_rank: Newbie
timestamp: August 25, 2015, 05:47:53 pm
content: Aw Dave, you didn't see the Game of Life generations going on the Glow-Tie? It is the 4th mode shown in the video after the VU meter one. Got really excited when I saw the Game of Life going!

author: apis
author_rank: Super Contributor
timestamp: August 25, 2015, 07:11:45 pm
content: I'm thinking about buying the fx991ex now, because I have been wanting one that does complex numbers in a convenient way. Made me take a look at my old (>15yr) fx-82LB, it's rated as 0.4 mW and still use the original casio branded alkalines!Those prototyping boards look nice but I wonder how much protection/regulation there is, I've had cheap ones before (ienotthe wombat one) and it's easy to mistakenly short something on the board since it's unprotected and can damage some of the components. It might have been better to put some acrylic over the board for protection?

author: Razor512
author_rank: Regular Contributor
timestamp: August 25, 2015, 07:22:54 pm
content: $500 is way too much for that gimbal ($500 is DSLR compatible gimbal territory), especially since it stabilizes similarly to those $50 gimbals for quad copters, though their build quality is lower, with exposed PCBs, and thinner aluminum construction material, at least based on rough comparisons from what I can find on youtube of people testing the cheap ebay gimbals.Though I did not see anything with vigorous movements like in the EEVblog video.

author: Porto
author_rank: Contributor
timestamp: August 25, 2015, 07:43:06 pm
content: SJ4000... a rip-off of a rip-off?

author: cteffects
author_rank: Newbie
timestamp: August 25, 2015, 07:43:41 pm
content: Very sexy shirtless flash-frame at around 9:20.

author: Neganur
author_rank: Unknown
timestamp: August 25, 2015, 07:59:01 pm
content: Quote from: Fungus on August 25, 2015, 02:57:53 pmThat's some 28 EUR for me after adding VATIndian Amazon sells them for ~15 EUR/17 USD incl shipping to Mumbai.Local shops in Helsinki: 35-38 EUR. Crazy.

author: apis
author_rank: Super Contributor
timestamp: August 25, 2015, 08:13:37 pm
content: Quote from: Neganur on August 25, 2015, 07:59:01 pmI see a lot of the cheap products you can buy for 1$ on ebay (including airmail from China) being sold in local shops for 10-20$. I'm guessing the Chinese sellers have a nice profit margin as well and most of that price is the shipping cost...Makes you wonder about what it actually cost to produce things and why the market prices are so different from production cost. Of course, market prices are not supposed to be production cost, rather it reflects what people are willing to pay. But in a free market economy they should be relatively similar? My theory is that there isn't nearly enough competition in most markets for it to be considered a working free market. For example, there is only one brand of razors you can buy around here. In any case, something isn't right.

author: max666
author_rank: Frequent Contributor
timestamp: August 25, 2015, 09:23:35 pm
content: Quote from: adrian on August 25, 2015, 05:47:53 pmI didn't notice the Game of Life, but Game of Life for the win!Nice profile picture by the way

author: acourtois
author_rank: Contributor
timestamp: August 25, 2015, 09:32:27 pm
content: I guess I am Dave approved.

author: pickle9000
author_rank: Super Contributor
timestamp: August 25, 2015, 10:23:47 pm
content: Brushless gimbalHere's an example of the kinds of shot's you can achieve. Lots of good shots on this channel.- Keep in mind that rapid changes in altitude will show as shake. An extended arm helps.- Framing is tricky, remote monitor is very helpful.- Use "follow mode" for most shots.

author: EEVblog
author_rank: Unknown
timestamp: August 26, 2015, 01:04:16 am
content: Quote from: adrian on August 25, 2015, 05:47:53 pmAh, missed that!

author: EEVblog
author_rank: Unknown
timestamp: August 26, 2015, 01:06:21 am
content: Quote from: acourtois on August 25, 2015, 09:32:27 pmNot with that TI you ain't

author: Christe4nM
author_rank: Unknown
timestamp: August 26, 2015, 02:55:55 am
content: You just got me to order a FX 991ex on eBay. It got my attention on looks then hooked me by being able to do binary and hexadecimal calculations and conversions. Smaller than my good old TI-84 too.

author: redshift
author_rank: Contributor
timestamp: August 26, 2015, 04:50:59 am
content: Quote from: mojo-chan on August 25, 2015, 09:27:21 pmMaybe one leftover frame from a scene that he decided to take out?Any explanation Dave?

author: pickle9000
author_rank: Super Contributor
timestamp: August 26, 2015, 04:55:52 am
content: Quote from: redshift on August 26, 2015, 04:50:59 amha ha.... awesome and juvenile

author: steve30
author_rank: Frequent Contributor
timestamp: August 26, 2015, 06:23:36 am
content: Ah ha!. I thought I saw his shirtless for a fraction of a second, but didn't bother to go back and look.

author: teerosheyal
author_rank: Newbie
timestamp: August 26, 2015, 08:04:05 am
content: In 42:08QuoteAnd i thought that everybody in Australia is called Bruce...

author: maartenva
author_rank: Newbie
timestamp: August 26, 2015, 09:38:23 am
content: If you want to translate the chinese manual, you can you use the google translate app on an android Phone.You can take a picture and it translate it for you to any language.https://play.google.com/store/apps/details?id=com.google.android.apps.translate&hl=enGreetings from BelgiumMaarten

author: Fungus
author_rank: Super Contributor
timestamp: August 26, 2015, 10:38:14 am
content: Quote from: Christe4nM on August 26, 2015, 02:55:55 amCan't you do those in your head? I dunno, youngsters today...I noticed there's an FX 991ex emulator you can download on the CASIO web site. I though I'd have a play around with it before deciding if I want one but I failed to get past their incredible software licensing system.I don't seem to have a "claim code". Do you have to actually buy a calculator to get one of those and be able to install the 90-day trial of the emulator?

author: ornea
author_rank: Unknown
timestamp: August 26, 2015, 10:41:13 am
content: Quote from: pickle9000 on August 26, 2015, 04:55:52 amImpressed 1/25 sec ... I didnt even notice the shirt change

author: ornea
author_rank: Unknown
timestamp: August 26, 2015, 10:47:36 am
content: Calculator came in the mail. Belongs in the mailbag.

author: Christe4nM
author_rank: Unknown
timestamp: August 26, 2015, 10:58:24 am
content: Quote from: Fungus on August 26, 2015, 10:38:14 amIf you mean binary to hex conversions and back, those you can do in your head indeed: peanuts. But I'm not that good when converting say 24 bits binary to decimalCurrently I use the windows calculator for that, but I strongly dislike the lack of a proper physical calculator that you can poke your fingers at....and I needed the excuse to buy that nice looking Casio

author: Eliminateur
author_rank: Regular Contributor
timestamp: August 26, 2015, 12:13:05 pm
content: 150 bucks for the bowtie?, hell no, funny novelty but not at that price

author: Fungus
author_rank: Super Contributor
timestamp: August 26, 2015, 01:44:01 pm
content: Quote from: Fungus on August 26, 2015, 10:38:14 amI figured it out. The trick is to ignore all the on-screen instructions and press 'cancel' when it asks you for the license code.Quote from: Christe4nM on August 26, 2015, 10:58:24 amTo be fair, that would be one of the reasons I'd buy one, too.But...I played with the emulator and seems like they managed to make it annoying. Not at all easy to use like Windows calculator.To convert a number you select your mode, type in a number,press '=', then press a number-base button to convert it.Yes, it's only one extra button but why can't I just press the number-base button without typing '=' first, like on Windows calculator? So near, yet so far away...I guess my venerable HP 20S lives another day.PS: Yes, the calculator accepts "sin(45" without a closing bracket.

author: SeanB
author_rank: Super Contributor
timestamp: August 26, 2015, 06:58:59 pm
content: I still use the Fx 602p I had in school, and it is IIRC on the third set of CR2032 cells since it was new. Used to have the companion printer, but that wore out, plus the pens it used were incredibly expensive as a student. Played nice music though through the cassette port.

author: apis
author_rank: Super Contributor
timestamp: August 26, 2015, 11:10:31 pm
content: Quote from: Fungus on August 26, 2015, 01:44:01 pmThanks!Have played with the emulator for a while now and the complex number mode is a bit limited, you can't take the square root of complex number for example, can't use complex numbers in matrices and so on. The 5800P looks like it would be more powerful but there is no emulator for it, and it's not perfect either. I might just go with the 991ex anyway, it's nice enough and cheap, for more complicated stuff I'll probably have to switch to the computer anyway.

author: Godzil
author_rank: Frequent Contributor
timestamp: August 27, 2015, 01:31:06 pm
content: About the timelapse feature and the SJ4000, I bought one because I need a cam for making timelapse and bougth the non Wifi one because I though it would have the same option as the Wifi one, and I don't really need Wifi for thisBut, in fact the non Wifi is capable to takes timelaps photo, it take them as photo and not as a video, but if you have the correct tools it's not a real problem. So hopefully, with a delay of 5/10 or 20s between each shot, it's possible to do a timelapse with the non Wifi SJ4000

author: pickle9000
author_rank: Super Contributor
timestamp: August 27, 2015, 02:39:15 pm
content: Quote from: Godzil on August 27, 2015, 01:31:06 pmI know dave has touched on most stuff but I'd like to see the camera / audio gear an a quick overview of a shoot / dub and computer editing session.

author: Harrkev
author_rank: Contributor
timestamp: August 27, 2015, 04:47:01 pm
content: Quote from: EEVblog on August 26, 2015, 01:06:21 amReal men use HP calculators. RPN is for engineers!

author: tjringsmose
author_rank: Newbie
timestamp: August 27, 2015, 05:59:35 pm
content: Quote from: Eliminateur on August 26, 2015, 12:13:05 pmI was thinking the same thing. A quick check on digikey says the 67 LEDs are about 7-8USD in total, if you're not that picky. Then theres a weird shape PCB, a µC and some difficult mounting, but 150 bucks??I'll give it a month before this pops up a 20USD including shipping on ebay - sorry to the kickstarters, it's a neato idea, but it's easily duplicable and extremely overpriced.

author: Godzil
author_rank: Frequent Contributor
timestamp: August 28, 2015, 12:32:07 am
content: I suspect that the LEDs are Adafruit NeoPixel and they are really cost, 67 LEDs cost much more than US$6-7Look on digikey:http://www.digikey.co.uk/product-search/en/optoelectronics/led-indication-discrete/524729?k=WS2812B2.3 each for 10 of them so 67 * 2.3 = $154,1...

author: Fungus
author_rank: Super Contributor
timestamp: August 28, 2015, 02:58:30 am
content: Quote from: Godzil on August 28, 2015, 12:32:07 amAdafruit neopixel are just WS2812 LEDs.Quote from: Godzil on August 28, 2015, 12:32:07 amhttp://www.ebay.com/itm/261844102963

author: Godzil
author_rank: Frequent Contributor
timestamp: August 28, 2015, 06:51:58 am
content: Excuse me, but you but components from dubious origin on eBay for production? I hope your device come with a 5year warranty that cover everything...

author: coppice
author_rank: Super Contributor
timestamp: August 28, 2015, 07:14:16 am
content: Quote from: Godzil on August 28, 2015, 06:51:58 amClearly the most important quality of a throw away novelty item is a 5 year warranty, and not a low price.

author: Godzil
author_rank: Frequent Contributor
timestamp: August 28, 2015, 08:24:13 am
content: And even if the eBay cheap version, $1 per LED will be $67. That's still far more than the $6-7 claimed earlier.

author: Votality
author_rank: Contributor
timestamp: August 28, 2015, 08:24:33 am
content: Dave? WTF

author: Fungus
author_rank: Super Contributor
timestamp: August 28, 2015, 09:28:18 am
content: Quote from: Godzil on August 28, 2015, 06:51:58 amAll the WS2812 LEDs are made by World Semi as far as I know. Adafruit, eBay... all come from the same factory.http://www.world-semi.com/en/Driver/Lighting/WS2811/WS212B/Here's Adafruit's datasheet:https://www.adafruit.com/datasheets/WS2812.pdfWhat does it say at the top of the page? "World Semi".

author: Fungus
author_rank: Super Contributor
timestamp: August 28, 2015, 09:29:25 am
content: Quote from: Godzil on August 28, 2015, 08:24:13 amThe eBay ones are 10 cents each in quantity. You can probably get them even cheaper if you buy direct.

author: Godzil
author_rank: Frequent Contributor
timestamp: August 28, 2015, 09:51:25 am
content: Quote from: Fungus on August 28, 2015, 09:28:18 amand? The eBay seller tiaochongyi is not World Semi.Have you ever heard about fake components, or second hand, or factory rejected chips?For a small quantity toy, or non professional product, buying on eBay, maybe (even if I will never do that unless that's the only way to buy the component) but for something that have to be manufactured, there is no way to buy from such an unreliable service.And digikey/mouser are not the cheapest distributors, for sure, but digikey list this component for $2.3/each, mouser they are at $4.03/each when buying, for both sellers, at least 10 of them.And this eBay guy is able to source them for $2.90 the whole 10 packages (so 0.29/each) ?Sorry but that look likes too good to be true.

author: Fungus
author_rank: Super Contributor
timestamp: August 28, 2015, 10:08:13 am
content: Quote from: Godzil on August 28, 2015, 09:51:25 amSure, but google for "fake ws2812" doesn't come up anything.Quote from: Godzil on August 28, 2015, 09:51:25 amYou might be right if it was only one seller but 20 cents per LED is a fairly typical price for WS2812 LED strips on eBay, and has been for a number of years. In fact you could get the older WS2812A LEDs for that much and they were more expensive (six pins on each LED instead of four)For raw LEDs in 1000-quantity reels you'd expect it to be cheaper. 10 cents each is perfectly reasonable.

author: Muttley Snickers
author_rank: Unknown
timestamp: August 28, 2015, 10:27:50 am
content: Quote from: Votality on August 28, 2015, 08:24:33 amUnconfirmed rumour has it that they have added gambling tables to the supporters lounge and a few lost all their chips, others lost a lot more and went home counting their blessings.

author: old gregg
author_rank: Regular Contributor
timestamp: August 31, 2015, 02:56:46 pm
content: talking about the vactrol shirt, I wonder if Dave watched "I dream of wires" documentary.Funny how all that modular synth sounds so esoteric when you do know about it

author: senso
author_rank: Frequent Contributor
timestamp: September 07, 2015, 10:52:45 am
content: Quote from: Godzil on August 28, 2015, 09:51:25 amIf you are into serious production you contact the manufacturer and order a reel or 10, and there is SO much people using the ws leds, they are not hard to get, they are no exotic or rare, just buy them, oh and dont pay 10x the price because it has a flower in it

author: Fungus
author_rank: Super Contributor
timestamp: September 17, 2015, 07:48:06 pm
content: This just arrived in the post...looks like it's the same seller!(See video at 27m44s if you don't get it...)

author: Godzil
author_rank: Frequent Contributor
timestamp: September 18, 2015, 07:01:58 am
content: What have you ordered?

author: Fungus
author_rank: Super Contributor
timestamp: September 18, 2015, 11:23:17 am
content: Quote from: Godzil on September 18, 2015, 07:01:58 amI actually ran the emulator for a couple of weeks on my desktop to see how well it works. In the end I thought "why not?", it's only $25 delivered.Now it's here...first impressions are a bit mixed. The red/blue writing above the keys is very low contrast against the shiny faux-carbon-fiber casing. Kinda hard to read. The keys also have very little travel.