Electronics Forum

The Lounge • Re: Amazing Musical Creation

2012-02-27T18:48:13-06:00

...and if you believe this is real, you need to engage some critical-thinking. If you look closely at the ball launchers, there's no sign of any control mechanism. Likewise on the launchers that direct the balls to multiple targets - there is no steering mechanism.

Incredible Music Machine Prank - University of Iowa

From Hoax Slayer:

A video that supposedly shows an incredible music machine created out of farm equipment is circulating via email and online. The video itself is certainly an incredible and inspiring piece of work. However, it is a work of computer animation and does not depict a real machine made of farm equipment or anything else. The video is a piece called Pipe Dream that was created by Wayne Lytle, and Dave Crognale and their team at Animusic, a content creation company located in Austin, Texas.

The company has created a number of quite amazing 3D computer graphics music animation videos that are available via the company website. According to information on the Animusic website:

Both the graphics and the music are entirely digitally synthesized. Virtual instruments are invented by building computer graphics models of objects that would appear to create the sound of the corresponding music synthesizer track. Graphical instruments range from being reminiscent of existing instruments to arbitrarily abstract.

Apparently, some unknown prankster saw fit to create a fanciful tale to go along with the unusual video. Even the university departments named in the message appear to be fictitious. There is no record of the "Robert M. Trammell Music Conservatory" or the "Sharon Wick School of Engineering" at the University of Iowa or anywhere else. According to an article about the prank email on Iowa's KCRG:

The machine is supposedly a collaborative effort between the Robert M. Trammell Music Conservatory and the Sharon Wick School of Engineering but if you search the campus high and low you’ll never find either of those buildings. They don’t exist.

There is no need to malign this fantastic animation by tacking on a foolish and totally fictitious cover story. Such clever work speaks for itself and needs no embellishment. Moreover, the real creators of the animation deserve credit for their genius. If you receive this email forward, please let the sender know the true origin of the "farm machine music" video.

It is awesome computer-generated animation. Enjoy it for the awesome work that it is.

Statistics: Posted by Jon Chandler — Mon Feb 27, 2012 6:48 pm

The Lounge • Amazing Musical Creation

2012-02-27T18:41:50-06:00

This video shows an amazing creation by the Robert M. Trammell Music Conservatory and the Sharon Wick School of Engineering. (click to watch the video)

From the You Tube page is the following description:

This is almost unbelievable. See how all of the balls wind up in catcher cones.

This incredible machine was built As a collaborative effort between the Robert M. Trammell Music Conservatory and the Sharon Wick School of Engineering at the University of Iowa Amazingly, 97% of the machines components came from John Deere Industries and Irrigation Equipment of Bancroft , Iowa ...Yes, farm equipment!

It took the team a combined 13,029 hours of set-up, alignment, calibration, and tuning before filming this video but as you can see it was WELL worth the effort.

It is now on display in the Matthew Gerhard Alumni Hall at the University of Iowa , and is already slated to be donated to the Smithsonian.

What is truly amazing is the this entire creation is controlled by a collection of five Arduinos! All of the pneumatics are controlled via solenoids using off0the-shelf shield boards. It's quite a programming effort.

Statistics: Posted by Jon Chandler — Mon Feb 27, 2012 6:41 pm

Electronic Projects and Home made Gadgets • Re: Acrylic Bolted Joints and Cemented Windows

2012-02-27T14:19:15-06:00

Digikey carries (some of) the PRD series from Proud Industries as I linked above. They don't seem to come tall enough for a 4x20 LCD.

The Mouser ones are from a company in Germany. The EA 017-9UKE model (which is in stock at Mouser) is designed for a 4x20 display but it appears to be only the bezel without a lens.

Statistics: Posted by Jon Chandler — Mon Feb 27, 2012 2:19 pm

Electronic Projects and Home made Gadgets • Re: Acrylic Bolted Joints and Cemented Windows

2012-02-27T13:46:23-06:00

You can buy LCD bezels from Newark and digi-key

Newark are hard to find but here a link to digi-key http://search.digikey.com/scripts/DkSea ... LCD+bezels

And http://www.mouser.com/Search/Refine.asp ... D%2bbezels

Statistics: Posted by be80be — Mon Feb 27, 2012 1:46 pm

Electronic Projects and Home made Gadgets • Re: Acrylic Bolted Joints and Cemented Windows

2012-02-27T07:39:37-06:00

I just did a little research on "4x20 LCD Bezel" and it turns out that there may be some solutions.

DH MicriSystems looks like the best bet.

If you have ever looked for a bezel for an LCD 4x20 text display you have probably discovered the same thing we did--it does not exist (until now). This bezel is injection molded ABS to which we adhere a clear 20mil polycarbonate lense to protect the LCD face. This part really dresses up your LCD projects by covering the cut edge of a face plate and hiding the metal frame of the LCD itself.

All this for only $3.50. Nice.

Proud Industries also offer some LCD bezels and at least one of their products is in stock at Digikey. Alas, none of their offerings seems to be the size I need.

Statistics: Posted by Jon Chandler — Mon Feb 27, 2012 7:39 am

Electronic Projects and Home made Gadgets • Re: Acrylic Bolted Joints and Cemented Windows

2012-02-27T07:05:20-06:00

A window with a rabbit milled around the edge would be a nice solution! I'm surprised that nobody (as far as I know) supplies pre-made windows in standard dimensions. Windows sized for 2x16 and 4x20 LCDs would cover a lot of situations.

A window like that could just be held in by the display pushing against the back as you say or could use a double-backed tape frame to hold it (some commercial enclosures do this) or it could even be glued in using silicon glue for a waterproof solution.

From what I've read, routing and sawing don't create the high residual stresses like laser-cutting does. It's kind of surprising that what seems to be more the more brutal machining methods are better for the material. I learned about the stress issues when I had something laser-cut and there was some residue left on the piece. "That will come right off with some rubbing alcohol" as was told when my parts were handed to me. I wiped the piece with an alcohol-soaked paper towel and the entire cut edge instantly had hundreds of cracks extending a couple mm or more.

Statistics: Posted by Jon Chandler — Mon Feb 27, 2012 7:05 am

The Lounge • Re: A Nuts&Volts Article on PCB Layout Problems

2012-02-27T06:29:59-06:00

Cripes, thats bad.

Having said that, we've had "experienced" people come in and do similar things for us. They seem to like just jumping in the deep end without thinking things through first. Cue disasters that someone else usually winds up fixing for them.

Mind you, I'm very suprised they had PCB's made up (even cheap ones) without first prototyping something. Stupid things like chattering relays, and realising you need an LCD are exactly the things that I would have thought you would have liked to have picked up with a prototype before launching into the final PCB. I always like to knock something up, even if it's not a complete system on a solderless breadboard just to check my sanity!

Fair play to them though for writing it all up and letting others learn from their mistakes!

Edit: Oh and ignorance of the low cost PCB houses these days is practically criminal!

Statistics: Posted by RangerBob — Mon Feb 27, 2012 6:29 am

Electronic Projects and Home made Gadgets • Re: Acrylic Bolted Joints and Cemented Windows

2012-02-27T06:18:54-06:00

Hey Jon,

Nice piece. Having only just started playing around with laser cut acrylic, I'm just a few steps behind. Was looking into the captive nut bolt solutions too.

Just a quick note about the LCD window, does it have to be glued at all? We have an existing product using a similar scheme; using a stepped window (steped to retain the window in) which is simply sandwiched by the LCD frame. It holds great, no rattling at all once the OLED is tightened down. Obviously the downside is the window has to be milled (not laser cut) to get the step.

Statistics: Posted by RangerBob — Mon Feb 27, 2012 6:18 am

Electronic Projects and Home made Gadgets • Re: Acrylic Bolted Joints and Cemented Windows

2012-02-27T00:44:42-06:00

I didn't mention the purpose of the LCD display stand. No plans at the moment - I just wanted to test the window technique. Since I needed an opaque piece and a clear piece to see the effect, I needed two pieces of material.

Since I ultimately want a window for an LCD display, it made since that it fit a display. Because I needed two pieces of material and I'd been wanting to try the bolting technique, it made sense to include a bolted joint.

Combine these pieces and it only makes sense to make something useful!

Statistics: Posted by Jon Chandler — Mon Feb 27, 2012 12:44 am

Electronic Projects and Home made Gadgets • Acrylic Bolted Joints and Cemented Windows

2012-02-26T22:22:26-06:00

I've been wanted to try a couple things with laser-cut acrylics. For a long while, I've wanted to try bolted 90° joins, often seen at Thingiverse. I started with information I found in How To: Make Cheap LaserCut Custom Boxes for Your DIY Electronics. I wouldn't quite make the patterns shown in the article work with Visio, so I created my own. My patterns are slightly different, in that I made the slot width the same as the nut dimension across the flats to better hold the nut. The result is a rigid joint that's easy to assemble.

Read full article...

Statistics: Posted by Jon Chandler — Sun Feb 26, 2012 10:22 pm

General Electronics • Re: Power Protection Circuits

2012-02-26T09:40:31-06:00

killersquirel11 wrote:
What about using a Zener diode in the crowbar circuit. Then you get protection from over-voltage and reverse connection (which I consider to be the two most likely to damage all of your expensive parts)?

Good suggestion killersquiell1. I thought this had already been posted here, but it was actually on the EEVBlog forum:

armandas wrote:
Looking at this image from Jon's website:

If you replace the diode with a zener, it will protect from both overvoltage and reverse voltage. Replace the fuse with a polyswitch and it will recover after reverse voltage is removed.

Sorry I didn't remember to share this back here.

Statistics: Posted by Jon Chandler — Sun Feb 26, 2012 9:40 am

The Lounge • Re: A Nuts&Volts Article on PCB Layout Problems

2012-02-26T07:05:59-06:00

my last two boards Itead did I found some minor errors after reviewing first thing in the morning (fresh pair of eyes)

For $700 the person could have purchased a 10 station IRRITROL controller AND a remote control setup.
The most expensive sprinkler controller I ever had to purchase was $1200 15 years ago. It has 36 stations, keypad input and an LED display.
Add a remote control = $250.
After I got some high school students wet the school district decided to allow me to purchase the remote control unit.
$700 for a small controller? wonder what that person was drinking or smoking.

Statistics: Posted by MrDEB — Sun Feb 26, 2012 7:05 am

The Lounge • A Nuts&Volts Article on PCB Layout Problems

2012-02-26T03:03:34-06:00

I just read an article in the March 2012 issue of Nuts&Volts about PCB design. I don't have the citation information handy but it's just as well. The article is kind of a nightmare.

This is a followup article to a lawn sprinkler controller. I don't think I read the first article but basically he's using a Rabbit module to control a number of relays to operate underground sprinklers. This article is about his missteps along the way to a successful design; the author is apparently experienced, mentioning a project when he worked for Intel. The intent of the article is good but it's kind of hard to imagine all the problems this guy had.

First, he mentions the desirability of having a circuit board made. It's cheap he says, costing only $100 to have a board made! There's the first mistake...not reading the pages of Digital-DIY or many other forums talking about the inexpensive boards at Itead and Seeed (and DorkBot in the US). Instead of $100 for a run, he would have spent less than $15 for a 4" x 4" board.

The first board run didn't work. He had to design a component in DIPTrace and didn't check the lead diameters - holes too small. Scratch $100.

Re-lays out the part. New boards made. Numbered the connector incorrectly, resulting in reversed polarity and exploding chips. Scratch another $100 for the board plus who knows how much for the parts.

Lays out the board again. Sort of works this time. He decides a sprinkler controller without an LCD display is kind of dumb. Scratch another $100 for a board on the trash heap.

He's using some kind of demux to drive more relays than port pins, shared with the LCD. Can't update the LCD while a relay is closed.

Some of the relays are chattering. Micro is 3.3 volts and his transistor calculations were made for 5 so the transistors don't turn on fully.

The relay ground path is too small. Opening a relay freezes the display.

The list goes on and on....and on!

The current board is apparently the 7th version. $700 to control lawn sprinklers. I'm not too familiar with RainBird controllers, but I'll bet you can buy a really nice one for less than $700 (and that's just the cost of the circuit board runs!).

The author brought up some good points about design but I think perhaps he missed the key point. THINK. It's not an option. THINK about what you want the project to do before you get started and THINK some more during the design. What does it NEED to do? What features might be added to make it better? What features might you add to make it easy to add other features later? (bringing out port pins to a connector, having provision for a UART interface?) Adding these extras costs almost nothing during the initial design and you don't have to populate the positions on the circuit board if they are not needed.

I'm never in too big of a rush to send off Gerbers for boards. Give the design some thought for a while after it's "done" and look at it with fresh eyes before you send it off to be built.

Statistics: Posted by Jon Chandler — Sun Feb 26, 2012 3:03 am

The Lounge • Re: Police Pursuit or Design Methodology?

2012-02-25T14:24:51-06:00

Jon Chandler wrote:
But as I watch it, I can't help but think it reminds me of a design methodology sometimes discussed here. I'll let you form your own opinions

Hummmmmmm..... I just have to wonder, for about 1 second

Statistics: Posted by W4GNS — Sat Feb 25, 2012 2:24 pm

The Lounge • Re: ds30 (boot)Loader

2012-02-25T14:09:35-06:00

Hi Graham
I am thinking of making an article on the Amicus 18 site around the DS30 Bootloader I would like to use your work and expand it for both chips?
Can you please contact me about this.
Thanks Paul V.

Statistics: Posted by pverburg — Sat Feb 25, 2012 2:09 pm

General Electronics • Re: Power Protection Circuits

2012-02-25T10:10:45-06:00

What about using a Zener diode in the crowbar circuit. Then you get protection from over-voltage and reverse connection (which I consider to be the two most likely to damage all of your expensive parts)?

Statistics: Posted by killersquirel11 — Sat Feb 25, 2012 10:10 am

The Lounge • Re: Police Pursuit or Design Methodology?

2012-02-25T09:10:33-06:00

hahaha! I know! I know! But... I'm not naming names.

However, that last maneuver was flawlessly executed by the police, quite impressive. Simultaneous 4 way block??? wow.

Statistics: Posted by mrbasher — Sat Feb 25, 2012 9:10 am

The Lounge • Police Pursuit or Design Methodology?

2012-02-25T08:50:09-06:00

W4GNS sent me this video and it's pretty wild. I think the title sums it up for Benny Hill fans. You might think Keystone Cops or Three Stooges as similar styles. Here is the You Tube link.

Police Pursuit - Benny Hill style

But as I watch it, I can't help but think it reminds me of a design methodology sometimes discussed here. I'll let you form your own opinions

Statistics: Posted by Jon Chandler — Sat Feb 25, 2012 8:50 am

The Lounge • Re: Help! I need to buy a few Dallas DS275 RS-232 chips

2012-02-23T20:30:03-06:00

Problem solved!!

Quest Components only has the 14 pin TSSOP version of the DS275 and the project I'm building (the Spare Time Gizmos ELF 2000 1802 computer) pc board requires the 8 pin DIP version. The "Find I.C." website gave me only dead end leads when I tried it.

What I should have done first was to check out Spare Time Gizmos Wiki page where there was a page that other people who were also building or had built the same COSMAC ELF 2000 pc board kit had posted where you can find all the parts to build the computer. There was a link there to Direct Components (http://www.componentsdirect.com/) that had over a 1000 in stock at around $5 each.

Anyone thinking about building a vintage COSMAC ELF computer based on the RCA 1802 CPU should check out the ELF 2000 at Spare Time Gizmos: http://www.sparetimegizmos.com/Hardware/Elf2K.htm
The partial kit includes three pc boards: the main computer board, a Disk, UART and Real Time Clock Board, and board that 100% emulates the very hard to find RCA CDP1861 Pixie Graphics chip. All for only $80. The owner of Spare Time Gizmos had originally sold out of all these kits a while ago, but because of popular demand has done one more run of these kits. 34 years ago when I was around 17 years old I built an "Elf II" sold by a company called Netronics R&D Ltd that cost $99. I sold it a couple years after I built it and regreted it ever since. The new Elf 2000 is far more advanced than that Elf II, but still has the "feel" of the original Elf II.

Best regards,

Jim VE7UV

Statistics: Posted by Jim_ve7uv — Thu Feb 23, 2012 8:30 pm

The Lounge • Re: Help! I need to buy a few Dallas DS275 RS-232 chips

2012-02-23T03:27:09-06:00

THE DS-275 is listed as obsolete and no longer available on Maxim's site.

A quick look at the data sheet shows that this chip is powered by the RS-232 interface and that there are no similar replacements. Some of the more common MAX-232 (many variations) chips should would without too many changes. You can supply them with 5 volts and 4 or 5 caps and they generate the +/- 12 volts needed for an RS-232 interface.

Statistics: Posted by Jon Chandler — Thu Feb 23, 2012 3:27 am

The Lounge • Re: Help! I need to buy a few Dallas DS275 RS-232 chips

2012-02-23T03:19:31-06:00

Welcome to Digital-DIY!

The best way to locate parts is FindChips.com. If you type in a part number, it searches the major suppliers and lists stock at each.

Use care, as searching for DS275 also find anything that starts with DS275, including the DS2756 fuel gage, which incidentally is also in short supply.

For the Dallas DS275, the situation is pretty bleak. The only place with stock is Quest Components, who claim to have over 21,000 in stock. I've never done any business with Quest before, so I can't speak to their reliability.

As a side note, Maxim (Dallas-Maxim) can be very generous with samples, but next to impossible to actually buy parts from when you need a supply. Many designers refuse to use Dallas-Maximum parts because the supply is so unreliable.

Statistics: Posted by Jon Chandler — Thu Feb 23, 2012 3:19 am

The Lounge • Help! I need to buy a few Dallas DS275 RS-232 chips

2012-02-22T20:51:13-06:00

Hi all,

I just became a member of Digital DIY and am totally impressed with this website! I came across this site "accidently" while searching for the chip I mention below I need. The link to this site was regarding a project that Graham had made. (I emailed him a couple minutes ago to see if he had any he would be ok with parting with)

Here is my problem:

There is a DIY electronics project I'm working on that uses the Dallas DS275 RS-232 transceiver I.C. in the 8 pin DIP format. I searched high and low on the net without any good leads on finding any for sale. I was hoping that some other member of this site might have some they would sell and take Paypal for payment, or send me a link (anywhere in the world is fine at this point!) to where someone has them actually in stock and for sale. Right now I just need one of them, but would like to buy three for future use.

Any help would be very much appreciated.

Thanks,

Jim VE7UV
BC, Canada

Statistics: Posted by Jim_ve7uv — Wed Feb 22, 2012 8:51 pm

Schematic Authoring • EEVBlogs 244 & 245 - PCB Layout of the Power Supply

2012-02-22T02:26:17-06:00

I've mentioned here that Dave at the EEVBlog is designed a computer controlled power supply. The videos are extremely good at explaining the practical side of design.

EEVBlogs 244 and 245 are 10 times real time videos of laying out the circuit board for the power supply. Dave is extremely knowledgeable in PCB design and has a PCB Design Tutorial linked in the references section.

Watching these videos is a little choppy with the screen flashing back and forth but it's interesting to watch a pro at work. As you'll see if you watch the video, it's a matter of trial and improvement to find a good board layout - what you start with may have little resemblance to the final result. I think this is a point often overlooked by non-experienced designers. The first attempt at arranging parts is probably not the best and ripup/rework is just part of the process.

I like one tip of Dave's. If the circuit has functional blocks, say the power supply components, arrange them off of the board into a workable group, getting all the parts nicely positioned with respect to each other. When a good arrangement is found, drag the block into the right position on the board. A few more adjustments may be needed of course but it's easier to work away from everything else.

EEVblog #244 – PSU Design Part 9 – PCB Layout

EEVblog #245 – PSU Design Part 10 – PCB Layout Editing

Statistics: Posted by Jon Chandler — Wed Feb 22, 2012 2:26 am

Electronic Projects and Home made Gadgets • Re: A Replacement Meter Lens - Fail

2012-02-21T17:56:18-06:00

One spray and it's gone for life it gets it first charge when you removed the film that keeps you from scratching it. After a nice little spray of ant static it never happens agin glass can charge to http://en.wikipedia.org/wiki/Electric_charge You may have silkie
finger's

Statistics: Posted by be80be — Tue Feb 21, 2012 5:56 pm

Electronic Projects and Home made Gadgets • Re: A Replacement Meter Lens - Fail

2012-02-21T12:11:52-06:00

Antistatic measures may work for the short term but wiping the face or a low humidity day could cause problems at some point in the future. Thanks for the suggestions but I'm going to cut a proper glass lens so I don't have to worry about it.

Statistics: Posted by Jon Chandler — Tue Feb 21, 2012 12:11 pm

Electronic Projects and Home made Gadgets • Re: A Replacement Meter Lens - Fail

2012-02-21T11:59:35-06:00

I recall that using the cloth thingies that go in the dryer will discharge the static as well?

Statistics: Posted by MrDEB — Tue Feb 21, 2012 11:59 am

Electronic Projects and Home made Gadgets • Re: A Replacement Meter Lens - Fail

2012-02-20T20:56:14-06:00

Jon Oh Jon they make antistatic spray you can spray it and you'll not have that problem .

The plexiglass charged when you pulled the plastic off it, But you can get some antistatic spray and fix that problem.........

Statistics: Posted by be80be — Mon Feb 20, 2012 8:56 pm

General Electronics • Soldering a QFN

2012-02-19T14:41:41-06:00

http://store.curiousinventor.com/guides/Surface_Mount_Soldering/QFN

Statistics: Posted by W4GNS — Sun Feb 19, 2012 2:41 pm

Electronic Projects and Home made Gadgets • Re: A Replacement Meter Lens - Fail

2012-02-19T13:17:49-06:00

You deserve an A for effort. At least you tried.
To bad about the static electricity.
If you don't have a glass cutter you might be better off having a glass shop cut out the odd shape. Unless you have a small belt sander with a carbide sanding belt.
Glass cutter = $2
Glass shop $3-$5
cut fingers and broken glass , priceless
Good Luck

Statistics: Posted by MrDEB — Sun Feb 19, 2012 1:17 pm

Electronic Projects and Home made Gadgets • A Replacement Meter Lens - Fail

2012-02-19T12:52:27-06:00

I recently found a great old Westinghouse AC Ammeter at Goodwill for a few bucks. I love the look of these old meters but this one had a cracked lens and a 50 year accumulation of cigarette smoke and grim on the case. I didn't take ant "before" pictures but here's how it looks cleaned up, minus a lens.

The meter face was almost brown from the accumulation of grime and cigarette smoke. I took the front cover off the meter and scrubbed it. It looks pretty good after cleaning as the above picture shows.

This article will show a great method of producing a life-size drawing of oddly shaped parts and document the less-than-successful process of replacing the lens.

Read full article...

Statistics: Posted by Jon Chandler — Sun Feb 19, 2012 12:52 pm