EEVblog #494 - Mailbag - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: July 14, 2013, 12:39:36 pm
content: USB Serial Module:http://jim.sh/ftx/DSRB-88 Geiger Counter:Induction Coin Shinker:http://thegeekgroup.org/stomperFPGA Development Board:http://de0-nano.terasic.com

author: ChrisBoden
author_rank: Contributor
timestamp: July 14, 2013, 02:00:52 pm
content: Thank you Dave!

author: c4757p
author_rank: Super Contributor
timestamp: July 14, 2013, 02:40:33 pm
content: I love how symmetrically shrunken the quarter is - the text and image aren't distorted at all! It's impressive that you can shrink something like that to two thirds its diameter in microseconds and do it so perfectly.

author: ddavidebor
author_rank: Super Contributor
timestamp: July 14, 2013, 03:03:07 pm
content: For the geiger counter try with a clock with luminescent background, the one that you can see in the dark.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: July 14, 2013, 03:11:34 pm
content: You probably have to lift the skirt off of the smoke detector to get a signal. It's just an alpha source, and probably covered with a metal can to keep the radiation out. Please weigh the quarters. My prediction would be that the compressed one is slightly heavier due to oxidation on the surface. And FPGA videos, yes please!

author: electronic_eel
author_rank: Regular Contributor
timestamp: July 14, 2013, 03:13:58 pm
content: Yes, please do some FPGA videos. I have just experience with microcontrollers yet and think reconfigurable logic is an interesting topic to learn something about.

author: dentaku
author_rank: Frequent Contributor
timestamp: July 14, 2013, 03:15:10 pm
content: Well, that made a decent dent in your mountain of mail.

author: ddavidebor
author_rank: Super Contributor
timestamp: July 14, 2013, 03:26:32 pm
content: But still a bit disappointed by this mailbag. A lot of (nice) postcard but only 2 nice items

author: c4757p
author_rank: Super Contributor
timestamp: July 14, 2013, 03:28:49 pm
content: Quote from: nitro2k01 on July 14, 2013, 03:11:34 pmCan two randomly selected, clean quarters be expected to have such similar mass that a bit of oxidation will make a measurable difference beyond the existing difference between them?

author: Winston
author_rank: Regular Contributor
timestamp: July 14, 2013, 04:22:36 pm
content: Idefinitelywant to see FPGA segments using the DE0-Nano, please. I've always wanted to know more about FPGAs.The Timberline Lodge you looked at in the Oregon calendar was used in the classic Stanley Kubrick film, "The Shining" which was a rare example of a movie that was far better than the novel it was based upon, thanks to Kubrick's great talent, of course. From Wikipedia:"The 1980 movie The Shining used aerial shots of the Timberline Lodge as part of its opening scene, and exterior footage for some establishing shots of the fictional Overlook Hotel throughout the movie. The movie was based on the Stephen King novel of the same name, which was inspired by The Stanley Hotel in Colorado.[citation needed] Several of the exterior shots in the film which purport to show the lodge, such as those of the hedge maze and loading dock, were taken at Elstree Studios in England, using a mock-up of the south face of the lodge. There is no hedge maze (and hardly any level ground) at the Timberline Lodge. All interior scenes were shot at Elstree Studios as well, and do not depict the interior of the Timberline Lodge."

author: TheWelly888
author_rank: Frequent Contributor
timestamp: July 14, 2013, 04:34:55 pm
content: Another vote for showing us the FPGA demo! It's a new area for me.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: July 14, 2013, 04:56:52 pm
content: Quote from: c4757p on July 14, 2013, 03:28:49 pmIf I knew, I wouldn't be asking. Then again, the question is if Dave has a precise enough scale.

author: c4757p
author_rank: Super Contributor
timestamp: July 14, 2013, 05:03:21 pm
content: That's probably about as likely as a chemist having a 6.5 digit multimeter.

author: SeanB
author_rank: Super Contributor
timestamp: July 14, 2013, 05:10:01 pm
content: I have the massmeters but not the crusher........

author: daqq
author_rank: Super Contributor
timestamp: July 14, 2013, 05:31:45 pm
content: Hi Dave,If you're looking for an accessible rad source, try thorium wolfram welding rods. It's not particularly radioactive, but certainly it's above the background.On the topic of your smoke detector - those are mostly made (or were) with americium 241 - an alpha emitter, which was enclosed in an ionization chamber - it would certainly not emit outside of the detector. Even if you were to open up its guts, the geiger counter might not be able to pick up the alpha particles.David

author: synapsis
author_rank: Regular Contributor
timestamp: July 14, 2013, 05:35:10 pm
content: Another thumbs up for FPGAs.I've had a DE0-Nano sitting on my desk for over a month and it's quite a bit to get your head around for "young players." I have experience in industrial PLCs and desktop multithreading, but I still need to adapt my thinking to concurrent execution.And you're not missing too much down here in Southern Arizona. We have the San Xavier Mission and the border "fence", with the occasional ghost town here and there. If you do get down here, I believe you'd really enjoy the Titan Missile Museum. It's interesting to see the 20+ year old control systems.

author: Winston
author_rank: Regular Contributor
timestamp: July 14, 2013, 05:45:22 pm
content: The Geek Group's quarter shrinking "stomper":Project Stomper Mark 4 Walkthrough (CGI)Early Stomper Tests (Crude Prototype)

author: Winston
author_rank: Regular Contributor
timestamp: July 14, 2013, 05:58:39 pm
content: Quote from: synapsis on July 14, 2013, 05:35:10 pmDon't forget the Kitt Peak National Observatory telescope complex!http://www.noao.edu/kpno/I was a visitor there long before the post-9/11 paranoia, so I don't know how things are done now, but I just walked around and into the various observatories which had plexiglass-enclosed public viewing areas within the domes. Awesome hardware! I was wearing a T-Shirt which said "Life's a Mountain, not a Beach" countering the popular T-shirt then which said "Life's a Beach" (after "life's a b*tch and then you die"). I was there during a weekday and was alone except for an older couple who were walking around like me who assumed I worked there, probably due to my relative youth and my T-shirt.Of course, Meteor Crater and the Grand Canyon are absolute must-sees in northern AZ. Petrified Forest National Park is fairly interesting, too, along with some ancient native American structures and a smallish volcano ash dome (can't recall the names of either). And, Dave, I don't know if it was just my viewing point, but on my second visit to the Grand Canyon I went to the northern side, more out of the way and not worth it in my opinion if you've already seen it from the southern side.

author: free_electron
author_rank: Super Contributor
timestamp: July 14, 2013, 06:48:06 pm
content: I watched some video's of Thegeekgroup thinking, cool , another hackerspace. but all i see is a bunch of rednecks having some fun of the type : hold my beer and watch this...I don't get it. Its supposed to be a hackerspace ... Very little hacking going on. All they do is yell out high voltages and then destroy coins .I don't get the obsession that people have with that stuff. It is dangerous , and useless.

author: synapsis
author_rank: Regular Contributor
timestamp: July 14, 2013, 07:40:00 pm
content: Quote from: Winston on July 14, 2013, 05:58:39 pmVery true. I grew up near the base of Kitt Peak (yes, middle of the desert nowhere) and totally forgot about it. Last time I was up there was 1986.

author: c4757p
author_rank: Super Contributor
timestamp: July 14, 2013, 07:45:22 pm
content: Quote from: free_electron on July 14, 2013, 06:48:06 pmIt's a challenge to build things and fun to watch what you built do something "big". Building something that can crush a coin like that isn't trivial (OK, it's not quite building an oscilloscope, either) and it's exciting to see your project do something you couldn't do yourself.People like "hold my beer" entertainment for a reason.

author: Winston
author_rank: Regular Contributor
timestamp: July 14, 2013, 08:01:17 pm
content: Quote from: free_electron on July 14, 2013, 06:48:06 pmPersonally, I just like concept of the tremendous symmetrical force of the EM field and counter-field produce by 100,000 amps flowing through a heavy gauge copper coil that vaporizes into a plasma while inducing as much as 1,000,000 amps within the quarter.Very cool.P.S. - I'm similarly fascinated with thermonuclear weapons.Back in the early 2000's when silver wasmuchcheaper, I asked this guy if he could shrink a 1 oz, pure silver Silver Eagle:http://www.capturedlightning.com/frames/interesting1.htmlBack then, I believe he may have had a different, lower energy system, so he said to send him a Silver Eagle, he'd give it a go, see if it worked, then send my shrunken coin (or debris) back at no cost to me. What a deal! It worked and he used my coin for his shrunk Silver Eagle photo (back then anyway; don't know if he still does and I don't have my coin handy to check which reminds me that I need to findwhere the heck I put it!)Semi-technical paper on his system:http://www.capturedlightning.com/photos/shrinker5.pdf

author: FrankBuss
author_rank: Unknown
timestamp: July 14, 2013, 08:51:37 pm
content: The DE0 nano board is nice, I have it too. In combination with NIOS you can write C programs with it and access (memory mapped) blocks implemented in VHDL (or Verilog). When I tested it, it was a bit difficult to integrate the SDRAM in NIOS, needed a PLL instance in Quartus to work, with the right phase shift etc., but then you have a good 32 bit soft core CPU and lots of RAM, and IPs on the FPGA to use. And with the Eclipse based IDE you can even single-step debug your programs.For VGA maybe take a look at my YaGraphCon project:http://www.frank-buss.de/yagraphcon/. The bit depth is a generic parameter, but only BRAM support so far, but easy to use if you just want to display something like text on a VGA display (sometimes you can even get them for free in the dumpster). Recently I changed it to a register based interface instead of the SPI interface, which works already with a 6502 soft core, which is inside a port of an Atari 2600 implementation I work on for the Turbo Chameleon for an OSD:https://github.com/FrankBuss/TCA2601/blob/master/YaGraphCon/YaGraphCon.vhdShould be easy to integrate as a component in NIOS, but I guess there are VGA controllers in the Quartus MegaWizard as well, but I can't find it. Anyway, always more interesting to write your own entity than using some IP block.

author: 99tito99
author_rank: Regular Contributor
timestamp: July 14, 2013, 09:49:44 pm
content: Hi Dave: Yes, maybe a multi-part blog on FPGAs and Nano FPGA Development Board(s). Part 1 for the Newbies (me included) would be brief intro to FPGAs, the basics, how they work, different types, etc. And then certainly several demo project including how to do the basic programming. Cheers, Science-Mark

author: Sine
author_rank: Newbie
timestamp: July 14, 2013, 10:49:01 pm
content: That radiation detector is a VERY crude one, the detecting tube looks like a MTX-90 cold cathode trigger tube that is used for absolutely everything ( including light switches apparently ) in Russia.

author: EEVblog
author_rank: Unknown
timestamp: July 14, 2013, 11:56:12 pm
content: Quote from: nitro2k01 on July 14, 2013, 03:11:34 pmI think that would be pretty pointless unless you knew the mass of the shrunken coin to begin with.I doubt the usual mass variation in two (used?) coins would be substantially lower than any measurable oxide layer.

author: dexters_lab
author_rank: Unknown
timestamp: July 15, 2013, 12:08:17 am
content: nice to see the counter arrived ok, the sbm10 tube is actually at the other end of the pcb under the wax, the mtx90 is i think just a light

author: LoyalServant
author_rank: Regular Contributor
timestamp: July 15, 2013, 12:09:46 am
content: Anotherfor FPGAs...It's something that I have been meaning to dabble in myself.

author: crisr
author_rank: Contributor
timestamp: July 15, 2013, 04:35:12 am
content: I too would love some segments about FPGAs! Like what kinds of applications they are best suited for or what can be simpler / faster / better with them, and also how VHDL / Verilog work...About the quarter, it either got some mass vaporized or it is thicker, I don't think the magnetic field could change the density of the metal.

author: CodyShaw
author_rank: Contributor
timestamp: July 15, 2013, 04:53:03 am
content: I have the DE0-Nano, it's a great board.See a little sample of something I made here:http://codyshaw.ca/2012/06/02/8-bit-adder-update/I really need to update my website...

author: ukee1593
author_rank: Contributor
timestamp: July 15, 2013, 06:30:54 am
content: I would love to see some FPGA based tutorial videos Dave!! I might have to get one of those development boards so I can play along at home

author: skylersaleh
author_rank: Newbie
timestamp: July 15, 2013, 07:50:57 am
content: I would very much like to see some FPGA videos.I actually own the exact same board, and have rather enjoined using it.

author: FrankBuss
author_rank: Unknown
timestamp: July 15, 2013, 08:07:07 am
content: Quote from: CodyShaw on July 15, 2013, 04:53:03 amNice. I don't know much Verilog, can you do loops with it to avoid instantiating every single one bit adder by hand? Would be worse for a 32 bit adder.Here is a 4 bit multiplier I created when I learned VHDL:http://tinyurl.com/odkh58pSee the "generate" loops, which would make it easy to implement a 32 bit multiplier without more code (but very many gates, because it is all static and parallel).

author: mrflibble
author_rank: Super Contributor
timestamp: July 15, 2013, 09:21:35 am
content: Quote from: FrankBuss on July 15, 2013, 08:07:07 amYup, verilog has agenerateblock that works pretty much the same way.

author: TheWelly888
author_rank: Frequent Contributor
timestamp: July 15, 2013, 12:29:03 pm
content: One question I have about FPGAs: What is the difference between microcontroller/processor based digital systems and FPGA based systems?

author: Rigby
author_rank: Super Contributor
timestamp: July 15, 2013, 12:31:32 pm
content: Dave, you said to let you know if we were keen on seeing a video where you generate video from GPIO (as my admittedly faulty memory is telling me, anyway) and I'd love it if you could show how to drive a 15kHz arcade monitor with GPIO, or something like it.

author: ptricks
author_rank: Frequent Contributor
timestamp: July 15, 2013, 01:04:13 pm
content: I have some of the microFTX usb-serial and like them a lot. The price is right and because they are so small it makes it possible to easily add them to things that have internal serial connections like routers, media player set top boxes, so that I don't have to wire up a serial port any time I want to access them, just connect a USB cable.

author: gardner
author_rank: Regular Contributor
timestamp: July 15, 2013, 01:17:35 pm
content: Quote from: Rigby on July 15, 2013, 12:31:32 pmThere is a widely used library for Arduino that bit-bashes B&W NTSC or PAL video using two pins and some resistors.The AVR ATMega is fast enough, but there is so little memory on the typical Arduinos that managing a frame buffer is pretty challenging.http://playground.arduino.cc/Main/TVout

author: carbon dude oxide
author_rank: Frequent Contributor
timestamp: July 15, 2013, 01:21:25 pm
content: I would definatly like to see some fpga videos, i have never used them or understood what they were so it would be very helpfull

author: ThomasChr
author_rank: Newbie
timestamp: July 15, 2013, 01:33:22 pm
content: @TheWelly888:FPGAs are some kind of programmable Logic.Think of them as Millions of Transistors which can be connected in any kind of way by a programming language (Verilog or VHDL).A FPGA Chip can make some simple AND, OR, NOT or it can be a whole Atmel Processor, or even an Intel Processor.You tell it what it is :-)Thomas

author: Unknown
author_rank: Unknown
timestamp: July 15, 2013, 01:36:42 pm
content: Quote from: carbon dude oxide on July 15, 2013, 01:21:25 pmYou're in for a treat! when the penny finally dropped for me I couldn't sleep properly for a whole week! ;-)

author: tridentsx
author_rank: Regular Contributor
timestamp: July 15, 2013, 02:00:49 pm
content: I want to see some projects with the fpga

author: c4757p
author_rank: Super Contributor
timestamp: July 15, 2013, 03:18:13 pm
content: QuoteLogic gates, not transistors! You're not going to get a long-tailed pair! Though I suppose you could build a CPU and stick SPICE on it...

author: iva
author_rank: Contributor
timestamp: July 15, 2013, 05:32:11 pm
content: Quote from: c4757p on July 14, 2013, 05:03:21 pmNot sure.I'm into ancient roman silver coins (besides software and hardware!) and I bought a jeweler's scales having a 0.001 g resolution for 70 euro, if you could point me to a 6.5 digits dmm for the same price that would be greatThe cool part is that having that resolution you could measure the specific gravity of a coin helping you determine fake ones or their composition - not that I personally did it but was fascinated by the idea:http://www.attilacoins.com/Calculate_Specific_Gravidity_coin.aspSorry for the OT which is still geeky enough for this forum (!), in any case +1 for the FPGA stuff, I usally play around with Xilinx tools and boards (I like them a lot) and would be great to have something about the competition.

author: mikepa
author_rank: Contributor
timestamp: July 16, 2013, 12:13:41 pm
content: One more vote for some FPGA videos

author: joab
author_rank: Newbie
timestamp: July 16, 2013, 03:16:17 pm
content: Nice! I also have a DE0 NANO. I got it just a short while ago so I haven't done anything with it yet, but my goal is to learn how to use FPGAs using it, together with my DE1 board. I've worked a bit with FPGAs in school, but haven't done much yet. I would love to see some videos where you use the FPGA.

author: deephaven
author_rank: Frequent Contributor
timestamp: July 16, 2013, 03:31:06 pm
content: FPGA videos are a brilliant idea. I'm just wondering if there will be Altera vs Xilinx fights like there are with Microchip vs Atmel

author: nitro2k01
author_rank: Frequent Contributor
timestamp: July 16, 2013, 04:17:26 pm
content: Quote from: deephaven on July 16, 2013, 03:31:06 pm"Some prefer one, some prefer the other. Both are perfectly good alternatives." Done!

author: ptricks
author_rank: Frequent Contributor
timestamp: July 16, 2013, 08:57:02 pm
content: Quote from: deephaven on July 16, 2013, 03:31:06 pmNothing to fight about, everyone knows that Altera is the best !

author: ddavidebor
author_rank: Super Contributor
timestamp: July 16, 2013, 09:30:57 pm
content: So, dave, seems like you have a 100% thumbs up for fpga!

author: FrankBuss
author_rank: Unknown
timestamp: July 16, 2013, 09:33:53 pm
content: The Lattice parts are nice too, e.g. the MachXO2: Powerful as a small Altera Cyclone (PLL, hardware multiplier etc.), but with integrated flash, like for CPLDs, and available down to WLCSP packages (that's 2.5mm^2).

author: ptricks
author_rank: Frequent Contributor
timestamp: July 18, 2013, 02:07:37 am
content: I was lucky enough to get one of these boards for cheap:http://www.embeddedarm.com/products/board-detail.php?product=TS-7300Arm 9, CPLD, FPGA all on the same board with pinouts, sd card slots and more.You boot off the sdcard into ARM Linux and then just use console commands to load and control the CPLD and FPGA. Makes development easy, no extra hardware required.You can even connect a keyboard and monitor and use the board to write the code for the FPGA .

author: FrankBuss
author_rank: Unknown
timestamp: July 18, 2013, 05:40:19 am
content: Quote from: ptricks on July 18, 2013, 02:07:37 amLooks good. The ARM CPU is a bit slow for todays standards, but a high speed bus between the CPU and the FPGA can be used for many interesting applications. I can't wait to get myParallela board.

author: Corporate666
author_rank: Unknown
timestamp: July 18, 2013, 07:52:35 pm
content: Big additional thumbs up for FPGA videos...I really love Dave's videos, but I have noticed that maybe as the blog has become more popular, there is more teardowns, equipment reviews, mailbag, etc. And there have been less videos which might appeal to real engineers and designers. This is not a criticism at all - Dave should do what sells of coursebut as for me, I would LOVE to see not only some FPGA videos, but it would be fantastic to see a few episodes about actually making something tangible... not just some example project blinking an LED, but a real project... similar to the Mu Current, or the USB power supply, or the exterior LED patio lighting. Something we can follow along with and see it being done... I miss those kinds of videos.

author: ddavidebor
author_rank: Super Contributor
timestamp: July 19, 2013, 12:56:51 am
content: the last time the project stuck...

author: JoannaK
author_rank: Frequent Contributor
timestamp: July 20, 2013, 12:51:35 am
content: This reminds me, I stilll haven't send my packet to Dave. Like year and half gone since I got the idea, well. Perhaps before Xmas.

author: SeanB
author_rank: Super Contributor
timestamp: July 20, 2013, 04:36:49 am
content: No problem, he might open it by the following Christmas........

author: carbon dude oxide
author_rank: Frequent Contributor
timestamp: July 20, 2013, 11:33:45 pm
content: Or the christmas after that

author: Crazy Ape
author_rank: Regular Contributor
timestamp: August 12, 2013, 03:39:56 am
content: Quote from: FrankBuss on July 15, 2013, 08:07:07 amI created a 4 bit multiplier in VHDL as well. I'll have to dig up the code.I was messing around a bit with some small capacity devices from both Xilinx and Altera. I do have a DE0 Nano so I guess I'll have to bust it out of it's box and join the fun. I'm sure I have some interesting code around.