EEVblog #759 - Mailbag - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: June 30, 2015, 12:37:17 am
content: A big mailbag episode, getting through lots of backlog.P.S. Yes I failed to twig to the cordless ESD strap. Will have to do a video debunking this!SPOILERS:NicaDrone EPM688 OpenGrab Electro Permanent MagnetFor UAV/drone payload pickuphttp://nicadrone.com/index.php?id_product=59&controller=productFused USB to UART adapter (FTDI-Free)https://www.tindie.com/stores/maxtch/A PCB designed in AutoCAD.Freescale tower system modular development platform:Perf prototype board:https://www.eevblog.com/forum/crowd-funded-projects/perf/Pulsed Light laser LIDAR modulehttp://pulsedlight3d.com/products/lidar-liteA fun FAIL button, and a whole lot more.

author: boffin
author_rank: Unknown
timestamp: June 30, 2015, 04:29:24 am
content: You came oh so close with MississaugaMISS - SA - SAW - GAAwesome mailbag as usual; now I'm off to eBay to find a Fail button.

author: codeboy2k
author_rank: Super Contributor
timestamp: June 30, 2015, 04:33:54 am
content: Nice mailbag, I liked the format, open first, teardown later ! that's a winner in my book.Mississauga -- I was born and raised there, but I'm in Vancouver now. It's quite a large city, I think it's now the sixth in Canada. It's named after The Mississauga Indian Tribe.Pronounciation: Almost everyone can't pronounce it on first seeing it. You guys got it pretty close.I grew up pronouncing it like this: Miss-sis-saw-ga ... that's an american english "saw" like the 'o' in 'long'. not the Australian 'saw' which you guys say like an american 'sore'

author: thewyliestcoyote
author_rank: Regular Contributor
timestamp: June 30, 2015, 05:06:39 am
content: Lacking permanent magnets like what is used OpenGrab used in side of microwave waveguides as lacking phase shifters, reversible gyrators, and attenuators. Different kind of material but the same effect of lacking DC magnetic field. Very cool!

author: Rasz
author_rank: Super Contributor
timestamp: June 30, 2015, 07:38:15 am
content: ESP8266 is NOT BLUETOOOOOOOOHHHHHHHHHHHHHHHHHHHHhhhhhhhhhhhhhhhhhhhhhhhhh!!!!!1111111oneI have to say Im loving the little guy. At first I wasnt sure, young noob with no interest in electronics? But Ryan(sp?) is confident, assertive and makes mailbags more dynamic and fun. Im probably the least enthusiastic guy around here, writing something positive for a change took a lot of mental energy from me

author: Yansi
author_rank: Super Contributor
timestamp: June 30, 2015, 11:08:55 am
content: Yeah, its a nice WiFi chip with a crazy firmware full of bugs, poorly documented features and things wildly changing from version to version.Nice mailbag, full of interesting stuff :-)Only the latching magnet didn't look quite 5kg capable, looked kind weak. Also using thyristors at 5 volt supply voltage and even two of those in series? I think there's no close to 50A, or even 300, jeeeez. Anyone measured the curent? I think not... That's nonsense. I'd like to see some discussion on the design.EDIT: Jeezus christ.. they even can't publis a schematic in PDF or PNG or whatever, some bloody stupid "upverter online tool" slow as a whack and web browser selective. Blargh...EDIT2: Okay, taking back the 5V, there is 40 volts in the caps. There is a LT3495 boost converter.

author: bktemp
author_rank: Super Contributor
timestamp: June 30, 2015, 11:43:42 am
content: After seeing those small caps I did say the same: 300A from those 2 caps? Never.But then I did the math: 40V/300A=0.133ohms. That is at least possible with low ESR caps.The schematic lists them as EEEFK1V331P, 330uF, 35V low ESR caps from Panasonic with 8mohm @100kHz. The 300A could be correct, but 40V is a bit too much.

author: rsjsouza
author_rank: Super Contributor
timestamp: June 30, 2015, 03:12:41 pm
content: Nice mailbag, and Ryan was very good in the video; it was really nice to see the interaction between the two of you.I also did schematics and some simple PCBs in Autocad in early 1990s on a 10MHz XT without math coprocessor... Pretty cool when I opened an existing file and the circuit was slowly redrawn, just like an animation effect where all the elements (lines, circles, rectangles, etc.) were drawn in the screen in the same order as originally placed.

author: janoc
author_rank: Super Contributor
timestamp: June 30, 2015, 03:20:36 pm
content: Quote from: Yansi on June 30, 2015, 11:08:55 amThere is 3rdparty firmware and development toolchain for it too, so you don't need to rely on the buggy default firmware.BTW, Dave, that wasUSB Bconnector, not A on that USB/UART adapter.

author: 8086
author_rank: Super Contributor
timestamp: June 30, 2015, 05:49:02 pm
content: I can't believe the youtube comments re. Ryan. So much negativity, as if all those people weren't awkward at his age.Maybe they're so old they can't remember, hahahaha.

author: gemby
author_rank: Contributor
timestamp: June 30, 2015, 07:15:03 pm
content: Dave, little trivia, have you noticed little golden bears on Josip Medved's boards? Medved ( his last name ) means bear on Croatian.

author: MobileWill
author_rank: Regular Contributor
timestamp: June 30, 2015, 07:36:29 pm
content: Quote from: Yansi on June 30, 2015, 11:08:55 amThe ESP8266 Wifi you are referring to isn't so bad if you use LUA firmware or Arduino firmware. Much better than the default AT command set firmware. Plus you can use it as a all-in-one, no extra micro needed. I need to get one of the SMD versions with more GPIO's.

author: bitwelder
author_rank: Super Contributor
timestamp: June 30, 2015, 09:52:18 pm
content: Regarding the USB to UART adapter, if you don't want to use a mini or micro USB format, I'd say that the choice of using the USB B (i.e. what's in the device shown at mailbag) is the most practical one, as everybody probably has a ton of USB A to USB B cables laying around, and the USB A end is plugged to the computer side.

author: dadler
author_rank: Unknown
timestamp: June 30, 2015, 10:08:06 pm
content: I like Ryan. Do not like the new format.It breaks up the discussion of an item over two disparate sections of the video. This means one has to seek to two locations in the video to see the coverage of an item. Sometimes your mailbag segments are used for reference (or even mini-reviews) later in the future. One can link directly to a specific offset in the video. By breaking it up, this is not possible as it would require two offsets.Please return to the old format

author: ataradov
author_rank: Super Contributor
timestamp: June 30, 2015, 10:56:31 pm
content: Quote from: 8086 on June 30, 2015, 05:49:02 pmTo be honest, I have not watched two last mailbags because of this. I don't want to be negative, but I also watch those videos for Dave unique style, not for awkward teenagers.And yes, I do remember being a teenager, and even now I'm not good in front of a camera, but I also don't appear in random youtuber's videos

author: Lightages
author_rank: Unknown
timestamp: July 01, 2015, 01:26:59 am
content: It is very nice of Dave to help out a newcomer to video blogging. I am sure everyone was a PHD and built like Arnold when they were 15Good work Ryan and don't let the morons get you down! Sure the morons outnumber the nice people in the world so let it run off your back like a duck. Let them be politicians and you can do real things.IMHO, if Dave didn't give Ryan a hand, it wouldn't be Dave. Good work Dave!

author: EEVblog
author_rank: Unknown
timestamp: July 01, 2015, 02:56:36 am
content: Quote from: dadler on June 30, 2015, 10:08:06 pmI will. I had no intention of changing style, this was just a one-off, but I was curious what people thought.

author: mtdoc
author_rank: Super Contributor
timestamp: July 01, 2015, 03:22:49 am
content: for giving Ryan some air time. He has potential.for the new format. I'm glad it's not a permanent change.

author: Barny
author_rank: Frequent Contributor
timestamp: July 01, 2015, 07:23:35 am
content: Yes, youre right.If the unpacking and the mini-teardown is done seperate, it looses the charm of the whole maibag-mini teardown concept

author: Muttley Snickers
author_rank: Unknown
timestamp: July 01, 2015, 09:07:28 am
content: Personally I didn't mind the format and it may have been a case of just trying to thin out the backlog of mail, opening an item then doing a quick review only to find that five minutes later another similar device had been received would be rather annoying and could cause a very good design or concept to potentially miss out on the deserved recognition.Making comparisons between similar devices seems not only more sensible to me but appears to make better use of Daves time, so leaving the reviews to the end in a bundle does benifit not only the products but those following along as well in my opinion.The only short fall that I see with rapidly going through the mail means that some products and probably more so letters that generous people went to a lot of trouble to send in on the expectation that they would get personal attention may feel let down somewhat.I think that Ryan did an excellent job and Dave did very well in boosting the boys confidence.Muttley Sniffles........I still have the flu......

author: Stonent
author_rank: Super Contributor
timestamp: July 01, 2015, 12:20:31 pm
content: In American:Nick-uh-rah-gwaMiss-uh-sah-gwa (as pronounced by my mom who is from Detroit which is fairly close to Canada)In one Spanish dilalect:Nick-ahr-ow-gwa (ow pronounced like "Ow! I just stubbed my toe!)

author: Jacko
author_rank: Contributor
timestamp: July 01, 2015, 01:06:19 pm
content: Two thumbs-up for Ryan. He should be a regular mailbag participant!Best regards, Jack

author: acourtois
author_rank: Contributor
timestamp: July 01, 2015, 07:16:42 pm
content: Dave was right, I did the mesh thing on the ground plane to eliminate warping.The larger your PCB is for a given thickness the greater the chances that warping will happen. The worst is not so much the warping itself. It is, a) the PCB trying to get back to its original shape and b) the integration of the PCB in its application, will create stress on the solder joints. This PCB did not have large packages, so that mitigated the issue into a second-class concern. The MCU on this was supposed to be an MC9S12, so the clock speed did not play a part in ground-plane design choices. Project was shelved for different reasons.

author: rollatorwieltje
author_rank: Unknown
timestamp: July 01, 2015, 08:32:34 pm
content: Quote from: 8086 on June 30, 2015, 05:49:02 pmYoutube comments in general are mostly toxic garbage anyway. It would be an improvement for everybody if Youtube removed comments completely. I've seen a few bloggers suffering from mental issues because they read all that garbage about themselves. Many people claim it doesn't hurt them but that really isn't true, it's a death by a thousand cuts.

author: Goober_in_CA
author_rank: Newbie
timestamp: July 01, 2015, 11:27:24 pm
content: I also like Ryan.Any thoughts of making Ryan more permanent?Great episode!Daryl

author: Stonent
author_rank: Super Contributor
timestamp: July 02, 2015, 12:46:15 am
content: I was wondering, where's Dave2 been?

author: EEVblog
author_rank: Unknown
timestamp: July 02, 2015, 12:48:13 am
content: Quote from: Stonent on July 02, 2015, 12:46:15 amBusy with study and other stuff. He's beavering away on various projects that will eventually see the light of day.

author: apis
author_rank: Super Contributor
timestamp: July 02, 2015, 02:26:00 pm
content: That magnet device is very cool, didn't know you could do that.And thumbs up for Ryan from me as well, nice to see another face on the show!

author: technix
author_rank: Super Contributor
timestamp: July 02, 2015, 03:31:14 pm
content: Thanks for putting my board in this post!Tindie screwed up my store addressBut I think Tindie support staff changed it back...I chose the full sized USB Type B for its reliability. Once I had snapped the USB micro-B off a board and damaged it beyond repair...Not wanting that happen in my own projects I will probably always use full-sized Type B if size allows.

author: JackP
author_rank: Regular Contributor
timestamp: July 02, 2015, 09:06:38 pm
content: Mini B's a pretty good compromise between size and robustness

author: Dave Turner
author_rank: Frequent Contributor
timestamp: July 03, 2015, 12:14:26 am
content: Dave,I really like your latest mailbag format with or without a partner; opening a lot to get through them and then later running 2 minute tear downs of interesting items or putting aside others for later and longer attention. It all seems to flow better, at least in my view.A minor frustration that I have had is that when you present an item to the camera by hand your camera takes so long to focus that one does not get a chance to see it properly before it is removed from the field of view. Having said that you are better/more polished than other bloggers that I am pleased to subscribe to.Perhaps you could have another camera arranged to focus on a plane immediately within reach, then possibly you could take feeds from both cameras via a mixer to a recorder. Thus a switch to pick which feed is recorded could speed production.Just a thought! You're the expert.RegardsDave

author: Rasz
author_rank: Super Contributor
timestamp: July 03, 2015, 06:59:15 am
content: Quote from: Dave Turner on July 03, 2015, 12:14:26 amgame streaming pr0s use OBS and switch between cameras live seamlessly with keyboard/remote shortcuts with no editingexample repair with such setup:shitton of turtorials on ze web how to set it all up, random one from googlehttps://www.youtube.com/playlist?list=PLADO0ZcWBBb62Fn-ExV1PwiAliCA-j7Rw

author: technix
author_rank: Super Contributor
timestamp: July 03, 2015, 09:07:04 am
content: Quote from: JackP on July 02, 2015, 09:06:38 pmThose are not really cheap, and are not updated for USB 3.0/3.1 should I ever need it. USB micro-B are just pain in the ass to solder with an iron and are fragile like balls to me. I still trust a good old through hole Type B soldered down solidly to the board - you will probably destroy the board to snap it off unlike micro-B that snaps off way easier.

author: EEVblog
author_rank: Unknown
timestamp: July 03, 2015, 10:43:35 am
content: Quote from: Dave Turner on July 03, 2015, 12:14:26 amIt wouldn't speed production up a huge amount, and ultimately quality is going to suffer with these sorts of systems.Take for example Chris Gammell's video for Contextual Electronics. He has multiple cameras setup, switches live, and pauses the recording when required. The result is direct MP4 file that is automatically uploaded. No editing required. 15 minutes of content takes 15 minutes to shoot (unless he pauses).That's great for the sort of stuff he does, but poor for what people expect of my (more polished) videos. Framing suffers, exposure suffers etc, and unless you use HDMI capture from real cameras (not webcams) quality suffers.My editing doesn't take that long, a 1 hour mailbag takes not much longer than an hour to edit.Also, unless you are 100% fixed setup to produce the same style of content day in day out, you'd always be dismantling rigs, moving camera, tripods etc around. And it takes longer to set back up to start a shoot. My cameras are always constantly moving around the lab shooting all different sorts of footage. Even having a power cable plugged in to power the camera is a PITA, let alone a big long awkward HDMI cable going off to a PC. It's my idea of a nightmare.Although I do plan to have such a system like this for putting together quick videos. e.g. a fixed PC with multiple webcams and/or production cams, the Targarno microscope, PC screen capture, monitor screen, X-Split software for live switching, pausing, and recording, and a dedicated wireless mic system to handle the audio no matter what the situation. So I can do live shows as well as record a semi-polished version to upload for people to watch later.

author: Dave Turner
author_rank: Frequent Contributor
timestamp: July 04, 2015, 08:36:25 pm
content: Thank you for your explanation.Given your camera set up, which I believe usually auto-focuses on faces, is there any practical way of speeding the focussing on the hand presented items (particularly the smaller ones) without interrupting the flow of your presentation?RegardsDave

author: jwm_
author_rank: Frequent Contributor
timestamp: July 04, 2015, 08:52:59 pm
content: Quote from: JackP on July 02, 2015, 09:06:38 pmMini is significantly less reliable than micro. Mini connectors are designed for only 1,500 insert/remove cycles. micro are designed for 10,000. There is no reason to use mini in anything nowadays and it has been officially deprecated as a bad idea all around.Full size B are also not designed for many insert/remove cycles, but are more robust due to their size, you may find yourself having to "tighten' it a bit by rebending the retaining grounding springs a little after a few thousand cycles, but I have never had one fail in a way a little cleaning didn't fix up. I tend to use them too for anything that already has some bulk to it, unless it is a pure charging/power port. in which case it is always micro.The connection between the connector and the board can be a weak point for micro though, They make versions with through-hole prongs that are going to be signifigantly more robust, especially if your pcb traces have a possibility of delaminating due to overheating or stress, surface only micro port + cheap pcb - extra mechanical strengthening beyond solder connection is asking for trouble.

author: EEVblog
author_rank: Unknown
timestamp: July 04, 2015, 10:51:27 pm
content: Quote from: Dave Turner on July 04, 2015, 08:36:25 pmNot really, no. The depth of field change is too large. It's simply a hard limitation of trying to do that sort of shot.I can attempt to set the camera further back and up the depth of field manually, but that requires:a) More light (so no video noise)b) Wireless mic setup instead of shotgun on camerac) Potential to get it wrong and screw all the footage (done that before)I could of course have a 2nd cam setup close I can show to stuff too, and then switch in editing, but then I'd have the problem of:a) Twice as much raw footage to copy and backupb) Extra editing time (syncing and fades required etc)c) Potential to forget the startIn which case it would likely be better to go two a live camera switch system like you proposed. But all simply to too to fix a problem that isn't a huge issue, and I think the mailbag would end up with a "live" choppy-feeling camera feel that would have it's own drawback in terms of what people like.But ultimately it's a simple solution to your issue, I just need to hold the object up to the camera for longer, make sure it focuses and stop yapping for a second until it does, and then edit out that delay. It's a laziness/discipline issue. People like to think of all sorts of complex workflow solutions for things like this, but it's usually not as complicated as you might think.

author: Dave Turner
author_rank: Frequent Contributor
timestamp: July 06, 2015, 07:39:38 pm
content: Bingo! I'm a firm believer in the principle of KISS.regardsDave