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A visit to the Thomas Edison National Historical Park

Jeff — Mon, 06 Feb 2012 21:33:42 +0000

Last month, on my way back home from 28C3, I had the opportunity to visit a truly amazing (and maybe underappreciated) historic site: the Thomas Edison National Historical Park.

The park, which is located in West Orange, New Jersey, includes Thomas Edison’s laboratory complex and his Glenmont mansion. I didn’t get to see the mansion, which frankly was less interesting to me (although I hear it features such novelties as a remotely-switched electrically-heated birdbath). Instead, I decided to focus my tour on the laboratories:

The remaining laboratory buildings are actually only a small part of what used to be a huge industrial factory and research center that spanned several blocks. Only a few of the original structures remain, the rest having been sold off and destroyed to make way for new development.

Here are just a few of the businesses that used to be located beyond the complex gates. One has to wonder what the “La Compania Edison Hispano-Americana” did:

Before I forget: This is not where Edison invented the light bulb. Or the phonograph. This is where Edison refined his original phonograph into a commercially viable product, developed the kinetoscope and several other motion picture devices, and developed Nickel-iron-alkaline storage batteries that powered early electric vehicles, among may other things. Many of Edison’s early inventions were developed in his Menlo Park laboratory in what is now called Edison, NJ.

With that out of the way, back to the tour…

My tour began in the Chemistry Lab.

The lab is (not surprisingly) wired with DC, and there are many DC outlets sprinkled around the lab:

There are chemicals everywhere. Storage cabinets on the walls are filled with hundreds of glass bottles, organized by base element (Antimony, Lead, Magnesium, Calcium).

The lab has been beautifully restored:

I last visited here over 20 years ago with my grandfather, and while my memories are fuzzy, I do not remember the facilities being in this condition. This is likely because the complex has seen significant restoration work in recent years. Just outside the chemistry lab, there is a small square on one wall that is still in unrestored condition:

After completing the chemistry lab tour (which I believe is the only guided tour at the facility), I moved on to the building that houses Edison’s library, a room bathed in incandescent light:

Very prominently featured in the library is this angel, who is holding aloft a lightbulb. I sense more than a little bit of ego here…

In one corner, a cubic foot of copper, a gift from a group of mining and smelting companies, who were no doubt overjoyed by the success of Edison’s electric lighting system and other inventions.

Here is Edison’s desk, though apparently he did not spend much time here, preferring to work upstairs in a more modest room:

Moving on, I next visited the storeroom, home to not only tools but also samples of hundreds if not thousands of natural materials. It is reported that this storeroom contains everything from a tortoise shell and elephant hide to “the eyeballs of a US senator”:

The storeroom is the gateway to the most spectacular room in the complex, the heavy machine shop:

Power for the machines originates at two enormous motors located in the back of the shop:

It is then transmitted through a terrifying network of pulleys and exposed belts to each of the machines. This was not a safe place to work:

Upstairs is the precision machine shop, where the machines are smaller and more unusual:

Just off the precision machine shop is the room where Edison preferred to work, surrounded by chemicals and his experiments, conveniently close to the machine shop foreman’s office:

Another room upstairs housed a recording studio for what was likely the world’s first record company. It is amusing to think that records were being recorded right next to an active machine shop, but apparently the sensitivity of early recording devices was so low that they did not pick up background noise.

You can imagine a performer belting into one of these primitive devices, surrounded by many different types of recording cones, suitable for various instruments:

The upstairs halls are lined with artifacts from the Edison company. The first phonograph:

A pair of Thomas Edison electric irons:

Early Christmas lights:

Back outside, here is the Black Maria, Edison’s famous motion picture recording studio. The first studio of its kind, the roof opens and the entire building can be rotated to capture the maximum amount of outside light, which was required by early movie cameras:

Apparently during WWII the Edison Company saw itself as a target, and constructed this bunker to protect and preserve documents and artifacts in their collection:

This concluded my tour. There are many more photos of the laboratory complex in this flickr set. And if you are ever in the area, I highly recommend paying a visit to this historic site.

Spotted on Facebook…

Jeff — Thu, 10 Nov 2011 23:52:40 +0000

Comic by Mandor. Thanks to Bryan Currey for bringing this one to my attention.

New podcasting setup for The Amp Hour

Jeff — Tue, 25 Oct 2011 18:47:39 +0000

After being hassled by Chris about my audio quality on The Amp Hour for the past year, I finally broke down and upgraded my podcasting microphone setup. Here are some photos of the new setup and some notes about my approach.

Here are most of the big (expensive) parts. Clockwise from the upper left:

Audio Technica AT2020 Condenser Microphone ($60 on eBay, I got the XLR version, not the USB version that Chris uses)
ART Tube MP Microphone Preamplifier ($55 on eBay)
Samson SP01 Shockmount Spider Mount ($24 on Amazon)
Swing Arm Magnifying Lamp ($28 from Harbor Freight Tools)

A few more miscellaneous bits:

20 foot XLR M-F cable ($5 on eBay)
10 foot 1/4″ to 1/8″ cable ($0, made with spare parts)
Nady MPF-6 6″ Pop Filter ($15 on Amazon)

I got the idea to convert a swing-arm desk lamp (often called an Architect’s Lamp) into a mic boom from the awesome site IKEA Hackers. (Today I discovered that ham radio guys have been doing this for years.)

The closest IKEA is 40 minutes away, so instead I went to Harbor Freight Tools and bought the cheapest swing arm lamp I could find. I removed the lamp portion (after you remove the adjusting knob, the shoulder-bolt can be removed and the lamp pulls out). Then I cut the power cord and unthreaded it from the lamp.

The swivel mount on the Samson SP01 comes apart easily, exposing a handy flat mounting tab that could be used to bolt the spider mount to all sorts of things…

…including the desk lamp. I used a 1/4″ nylon spacer to fill the gap left by the narrow tab on the shock mount and some lock-washers to keep the mount from rotating when the adjustment is tightened. The original shoulder-bolt stripped (oops) so I replaced it with a beefier 10-32 bolt and corresponding nut.

While my initial tests with just the AT2020 mic were promising, I found that the swing-arm sagged under the extra weight of the shock mount. To solve this problem, I drilled two extra holes at 1″ intervals from the original spring perch on the swing-arm. This allows me to adjust the spring tension to balance the arm. Now the mic stays where I put it.

Here is the finished setup. I removed the heavy bracket and gooseneck from the pop filter and zip tied it to the front of the shock mount. The spacing between the pop filter and the mic comes out just about right.

Here’s the mic preamp. It’s got tubes! The microphone connects to the preamp through the XLR cable. The output of the preamp is connected to my PC’s line input through the junkbox 1/4″ to 1/8″ cable.

The best part about the swing arm setup is that when I’m not using the microphone, I can just swing it out of the way:

I’m really happy with the new setup, but you can judge it for yourself on this week’s episode of The Amp Hour (Xenomorphic Xerox Xebec).

Wilson joins the Cats of Engineering

Jeff — Tue, 25 Oct 2011 14:43:38 +0000

I’m proud to announce that my cat Wilson has joined the Cats of Engineering, a corner of Adafruit Industries devoted to the feline companions of engineers.

Wilson is a frequent contributor to the blog (in the form of typos) and involved in most aspects of life here at MightyOhm.

More cuteness! (Flickr photos tagged with ‘wilson’)

I was not prepared for this.

Jeff — Thu, 14 Jul 2011 05:15:37 +0000

People said that it gets hot here.

I thought that I understood hot. “I’ve lived in hot places before”, I said to myself.

Sure, Sacramento gets pretty warm in the summer. Maybe one or two weeks of 100+ weather in August.

But never have I experienced anything like this.

In January, we had snow one week and 70 degree weather the next. By February it was in the 80s, March and April in the mid-90s. By May, we had our first 100 degree day, and I suspect that it has only dipped below 100 briefly a couple times since.

The house AC has been running constantly, I’m scared to open the power bill every month, the lawn is dead (we’ve had just over 4 inches of rain so far this year), and I pretty much hide indoors anytime before midnight.

I guess the good thing is that unlike last August, when we first moved to Austin, the temps have been dipping down into the 70s at night. I remember when we first moved here, it was 100+ during the day and 95 at night.

That was rough.

Amusingly, when it’s this hot for this long, you do sort of get used to it. Kylie and I have gone out a few times lately and said to each other “wow, it’s nice out tonight”, then checked the weather:

95 degrees.

Lutowanie Jest Proste (Soldering is Easy – Polish Translation)

Jeff — Sat, 09 Jul 2011 07:12:04 +0000

MSP430 enthusiast Mark sent us this Polish translation of the Soldering is Easy comic book.

Thanks, Mark!

Rule 0

Jeff — Mon, 09 May 2011 22:50:25 +0000

…

I note one of you has his hand and wants to ask a question. Go ahead. “What is our hackerspace’s philosophy?” you ask. Well I’m glad you asked that question as I was struggling to come up with an un-contrived way to work this into a blog post. You really saved my bacon. Well our hackspace can been summed up with three sayings.

0) Don’t be on fire.

This embodies our essential and fundamental philosophical belief that each individual human should strive not to combust in an oxygen rich atmosphere. The rules of thermodynamics are against us, but with care we have so far managed to maintain this rule. We have enshrined this philosophy as our hackspaces rule 0, showing the reverence that we hold this axiom.

1) Well volunteered.

We believe in self-empowerment and also spreading out power among our members. So whenever someone suggests a project or problem that needs fixing they become responsible for implementing it.

2) Let me show you this neat thing.

We enjoy sharing our knowledge and projects with other people, this extends to young hackdays where we teach young kids about technology and how to make things.

I stumbled on this gem from London Hackspace while judging entries to the 2011 Great Global Hackerspace Challenge.

The five finalists from the ~30 hackerspaces that entered (not all listed here) will be announced soon!

You’re doing it wrong.

Jeff — Sat, 23 Apr 2011 09:29:33 +0000

From our friends in Russia comes this reminder that one should not take our instructions to “hold the soldering iron in your dominant hand, like you would hold a pencil” too literally.

Donate your spare CPU cycles to World Community Grid

Jeff — Mon, 17 Jan 2011 16:19:37 +0000

Here’s an interesting way to donate your spare CPU cycles to a good cause. This project has been around for a few years now, but I just started participating.

Running the software reminds me of my college days. There was a time when everyone I knew was running the SETI@Home screensaver (most likely on an AMD K6 or Celeron 300A!)

Clients are available for all major operating systems.

Scare the hell out of your secretary…

Jeff — Fri, 14 Jan 2011 20:51:23 +0000

“Scare the hell out of your secretary. Get her a computer.”

Very un-PC (no, the other PC) ~~1960s~~ 1970s ad by San Antonio-based Computer Terminal Corporation. Spotted at the Goodwill Computer Museum in Austin, TX.

Best viewed large.

HV Rescue Shield 2 and ICSPOV Shipping Update

Jeff — Wed, 15 Dec 2010 20:33:28 +0000

This week I’ve been busily shipping orders for the HV Rescue Shield 2 and the ICSPOV. Some folks have been buying one of each kit and building their own mightyohm sampler pack. Cool!

A couple notes about shipping:

While the shipping notes on the product pages say to allow 1-2 weeks, this is really the worst-case scenario (parts shortages, I’m on travel, etc.). Typically I ship within 3 business days max, and often I ship the next business day if possible. Domestic customers, you will typically receive your order within 5-6 business days. International shipping takes quite a bit longer because of the shipping time and customs delays.
I will not be shipping orders between Dec. 23rd and Dec. 30th, so if you place an order during this time, you’ll get it sometime after Jan 1st. If you want kits sooner, order before 12PM CST on Dec 22nd.

Lastly, I want to thank everyone who has placed orders this week. Thank you!

Happy Holidays everyone.

- Jeff

AVRISP mkII libusb drivers for Windows 7 / Vista x64

Jeff — Thu, 16 Sep 2010 17:49:49 +0000

Continuing on the theme of my last post, here are libusb-win32 drivers for the Atmel AVRISP mkII. Unlike the Atmel-supplied drivers, these support avrdude, and as a bonus they will install on the 64-bit version of Windows 7 without digital signature errors. Yes!

avrispmkii_libusb-win32_1.2.1.0.zip

Note that if you want to use the AVRISP mkII with AVR Studio, these are not the drivers you are looking for. You want the ones Atmel provides (if you installed the libusb drivers by mistake, re-run the AVR Studio installer to revert back).

Ahh, that’s better!

Jeff — Mon, 30 Aug 2010 16:34:01 +0000

About a month ago, I complained about Time Warner’s anemic upstream bandwidth cap on home cable modem service. (512k! Oh, the humanity!)

Well, a phone call to Time Warner and $10 a month later, my cap has been increased to 2 Mb. They call this their “Turbo” plan. (Turbo == fast, right?)

The asymmetry of my speedtest result below is still laughable, but the improvement in upstream AND downstream performance is very noticeable. Now my uploads to Flickr don’t completely saturate the connection and more than one person can actually use the network without hosing everyone else.

I still suspect that my upstream bandwidth puts a cap on the actual download performance I can achieve. I haven’t been able to find a rule of thumb to calculate how much upstream bandwidth is required to support a 20+ Mb/s download.

Surely there is a relationship between data coming down the pipe and the acknowledgements (or other handshaking packets) that are sent back?

Measuring network performance with iperf

Jeff — Mon, 16 Aug 2010 16:41:15 +0000

My new place in Austin came with a huge perk for a tech geek like me – it came pre-wired for ethernet in every room. (Well, technically not every room is wired. The laundry room, bathrooms, and garage are not, an understandable oversight.)

After installing a new D-Link Gigabit Ethernet Switch, I wanted to check the throughput to see if I was actually getting gigabit speeds – particularly because the house is wired with CAT-5e cable (and not the recommended CAT-6).

There are many ways to measure network throughput. In the past I have usually copied a file across the network and used a stopwatch to get a relative sense of speed. However, due to file sharing protocol overhead I always got disappointing results and never knew maximum capability of my network.

This time, based on the advice of a more network-savvy friend, I decided to use a command-line tool called iperf.

iperf is a command-line tool to measure network performance. It is very powerful, but also easy to use for simple tests. For a more complete overview of what iperf is and what it can be used for, check out this tutorial or the iperf page on Wikipedia. iperf has a lot of options, and I won’t cover the majority of them here. For more usage information, consult the iperf manual.

If you run Debian or Ubuntu (Linux), iperf can be installed by executing

sudo apt-get install iperf

I did these tests with OS X on the Mac since both of my Macs have gigabit ethernet ports and my older PCs don’t. A package for iperf is conveniently available from Macports. It can be installed via the graphical package manager Porticus or opening a Terminal window and typing

sudo port install iperf

In my case, all I wanted was a quick test of TCP/IP network performance. This is easy to do, but it requires two computers, a client and a server, both connected to the network under test. Ideally, there should be no other network traffic during the test, as this will affect the results.

On the first computer, launch the iperf server by executing

iperf -s

You should see something like this:

------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 64.0 KByte (default)
------------------------------------------------------------

On the 2nd computer (the client), open a Terminal window and run

iperf -c  -i 1

Within a few seconds, you should start to see reports coming in on both the client and server terminal windows:

------------------------------------------------------------
Client connecting to mini.home, TCP port 5001
TCP window size:   129 KByte (default)
------------------------------------------------------------
[  3] local 192.168.24.135 port 65142 connected with 192.168.24.77 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 1.0 sec    110 MBytes    924 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  1.0- 2.0 sec    101 MBytes    850 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  2.0- 3.0 sec    109 MBytes    914 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  3.0- 4.0 sec    100 MBytes    841 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  4.0- 5.0 sec    111 MBytes    927 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  5.0- 6.0 sec    102 MBytes    853 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  6.0- 7.0 sec    110 MBytes    923 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  7.0- 8.0 sec    102 MBytes    858 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  8.0- 9.0 sec  79.4 MBytes    666 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  9.0-10.0 sec  93.6 MBytes    785 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1018 MBytes    854 Mbits/sec

The last report (for the interval 0.0-10.0 sec) is the average throughput for the entire test. I’m more than happy with 854 Mbits (927 Mbits/sec peak!) given my fairly long runs of CAT-5e cable and other machines using the network. Contrast this with my results over 802.11g wireless:

[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  24.9 MBytes  20.9 Mbits/sec

Ouch.

Getting settled in Austin

Jeff — Mon, 02 Aug 2010 18:39:49 +0000

We made it! Driving a moving truck almost 2000 miles across America was no picnic (it gets HOT in Arizona) but ~4 days of travel were relatively uneventful (only one flat tire!). Pretty much everything made it intact, including a few hundred pounds of lab benches and equipment. (Note to self, next time get twice as many moving pads as seems necessary!)

My wife and I have been getting acquainted with our new city. One of the interesting/unique things about Austin is the local trailer food scene. One example, shown below, is odd duck, where you can purchase local, sustainable, gourmet wood fired food out of a trailer in South Austin. Yum.

The biggest downside to Austin I have found so far (aside from the lack of In-n-Out and Trader Joe’s) has been the pitiful upstream bandwidth that Time Warner provides with their Roadrunner internet service. Check out these Speedtest results:

Holy asymmetric internet access, Batman!

Compare those results with this test I ran before I packed up my computer in San Francisco:

Over 4 megabits! If only I knew how lucky I was on Comcast when I could upload entire Flickr albums and HD videos in minutes!

Time Warner – 512K? Really?

Ok, that’s enough for now – time to unpack the power supplies and oscilloscope.

PS. I almost forgot. There are a few pictures of the move on Flickr.