μblog: engineering from the trenches

Some time ago, I wrote a guide for compiling OpenWRT firmware for the la Fonera router. I began to really like OpenWRT and decided that I may want to put it on some other devices I have around, namely a Linksys WAP54G and WRT54G. I could have modified my development suite, however, I figured that it is better to let someone else do the work this time. Freifunk has done just that and has posted modified OpenWRT images that will even fit on the limited WAP54G. I have one of the TRX files loaded on my version 2.0 WAP54G and running without problems. The only slight hickup was that the Linksys firmware did not want to “downgrade”, so I pointed the a browser to http://router_ip/fw-conf.asp and disabled both check there and then simply uploaded the new TRX file using the updater. When everything was done, the router was back up on the same IP and was accepting ssh connections with username “root” and password “admin”. [I previously posted the password was "password", that is incorrect, sorry for the error.]

[ Image is from KJH.com ]

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We got some new drives in the lab today and I accidentally looked at the power consumption of these 1TB SATA drives and discovered that the +5V line required 700mA and the +12V line required a mere 550mA to operate. I compared it to 200GB Maxtor drive and noted that the +5V rating was about the same, however, the +12V rating was 1500mA. The 12W power rating reduction is impressive. WD’s product specifications page notes that read/write power is about 7W while idle power consumption is around 4W. Anandtech claims that Seagate’s 1TB drive is also fairly efficient. Please understand that I have no financial interest in selling these drives, I am simply impressed that we can get 1TB of storage in such an energy-efficient footprint. Combining this with one of an energy-efficient x86 system could soon become the new trend in always-on home media servers.

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Dear illustrious reader,

You have come here to find (hopefully) some great (terrible) information, or perhaps something relating to engineering. Not this time, this time I will use this place to put forth a public complaint, as well as the counter point. My gripe is with Comcast. Having just written a small summary regarding comping custom Fonera images, I figured that I would try to write something up regarding cross-compiling from a favorite operating system called FreeBSD. I followed the same footsteps, create a VMware configuration, download the latest FreeBSD ISO (i386) but then it stuck me, lets use BitTorrent! System activates and then nothing else works, meaning, while I am downloading the ISO, I can’t even check my email. Others have seen some of the same problems. So if Comcast is actively downgrading my connection using some silly tool, what can I do? There is no answer. I live in the middle of nowhere there is only one viable broadband provider with whom I must live.

The counter point is that Comcast owns the infrastructure, so they should be able to shape traffic regardless of any group of individuals that stand in their way.

Summary: The United States is an area that is sparsely populated so that most geographical areas can be controlled by one or two monopolies without competition.

Please feel free to comment to let us know how excellent/terrible your service has been and where you are located.

Dear illustrious reader, I commend you for making this far. Thank you for reading my blog.

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Phil, from rancidbacon.com, has let me know that many of the links on here are broken for Camino browser on OSX and resulted in him seeing a hotlink message. I am guessing that this was a problem for other people as well. I would like to apologize for the broken code and the resulting poor browsing experience. I have disabled the hotlink code and will likely keep it off until I start getting close to my bandwidth quota. Thanks again for the information.

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Many of us know that today, the last day of 2007, is the day that this years alcoholic products expire and therefore must be destroyed in some way. Although some prefer to pour these products down the drain, most will yield their bodies to this effort and destroy alcohol through consumption.

Ethanol is the primary active chemical in beers, wines and liquors. There are trace amounts of other alcohols which may alter the drinks effects, however, they are typically the minority. As chemicals go, ethanol (200proof, dehydrated) has a published material safety data sheet. This sheet should be printed out and posted in a conspicuous place at your drinking establishment so that individuals partaking will stay safe. Below are some symptoms, from the MSDS Section III: Hazard Identification, which may indicate to party goers that they are indeed consuming some amounts of ethanol:

Swallowing: May cause dizziness, faintness, drowsiness,
decreased awareness or responsiveness, nausea, vomiting,
staggering gait, lack of coordination, and coma

There is another document available which describes the metabolic mechanism for alcohol (ethanol). The summary is as follows:

• Reduces liver glycolosis,  leads to low blood sugar levels
• Reduces retinal production, leads to temporarily impaired night vision
• Uses water, leads to additional dehydration

So the basic idea is to avoid driving after drinking, space out your drinking over time and make sure you eat, to get adequate sleep with lots of water, and to go for a sweet drink instead of a coffee in the morning. Hopefully, by working together, we can solve this problem of expiring alcohol and have a pleasant New Years Eve.

2007 has been a great year, thanks to everyone for reading and commenting. See you in 2008!

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Looking through webserver logs, I noticed that some people were using a search engine to find this blog. They remembered part of the url, but not the whole thing. This is understandable since microblog is pretty generic and it is not even the domain name. To make things easier, I am forwarding all of the traffic from ENGR.BIZ over here, so until I come up with a good idea for that domain name, it can serve as an easier-to-remember alias for microblog.routed.net.

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I came across this interesting post at the Mouse Print blog and thought, that I have found a compliment to feature creep. The keen observation was that the Dial soap company introduced a grip feature to the soap and added “all day odor protection” and reduced the size of the bars from 4.5 to 4.0 oz. From reading the comments, the Mouse Print readers were unhappy and one recalled the days when soap was bars were 5.0 oz. Those readers, and I am sure some other consumers, seemed to feel that the soap was less effective because of reduced size and thereby less of a value for them.

This line of reasoning to me was odd because soap, and detergent for that matter, has very little of the main active ingredient, called surfactant, in relation to the overall weight or volume. This is the chemical that has both hydrophobic and hydrophilic end groups and is can be used to allow water to act as a solvent for fats. This chemical also facilitates soap bubbles by reducing the surface tension between water and air and forming a air-surfactant-water-surfactant-air interface.  Anywhere from 1% to 5% is probably sufficient to get a nice, creamy lather and a clean wash. Most of the remaining mass of the soap is can be made up of something like a paraffin wax and lotions with trace amounts of anti-bacterial chemicals and deodorants. The point that I am trying to make is that we can have a much smaller bar of soap do the same job as a larger bar of soap by keeping the amount of surfactant in the two bars about the same and by altering the waxy substrate for increased longevity. The addition of odor-fighting chemicals on the package seems to indicate that at least some of the soap chemistry was changed, so it may be possible that other chemistry was also altered and the slightly smaller bar of soap will still last for just as many showers as the larger one. A single milliliter of Tween-80, a popular commercial surfactant, is probably enough to clean a load of laundry, however, people still have the mentality that adding more detergent will give a better wash.

A topic closer to the thoughts of many engineers may be the Everex TC2505 being sold at Walmart. What is interesting is that the mid-sized tower contains a mini-ITX mainboard with a Via C7-D processor, something that can fit into the same volume as four or five DVD cases. It is suggested that Walmart performed some market research and concluded that people still see size as an indication of performance for a desktop computer and would therefore think that a smaller system would be inferior.

My conclusion is that changing an existing design characteristics, like size, is very difficult and doomed to rejection by the consumer. The best hope is to try to launch a new product and hope to put positive spin on the improvements. In 1985, the Coca Cola drink recipe was altered resulting in a backlash and a subsequent re-introduction of Coke Classic. Diet Coke, however, has received a warm reception from many. As far as the soap goes, a whole new application will have to be designed. Although body wash is fairly new, we are already ingrained with the idea that we need about a tea-spoon of it to wash up. I guess the future could be some soft device with built in electronics and microfluidicts. It would be the size of a good, old fashion bar of soap and will feature a button and a LED. When we press the button, the LED will blink, the microfluidics will dispense micro-liters of surfactant and deodorant to the device’s surface and the device will wiggle or click a little letting us know that something useful has happened. We will lather and wash with it just like normal soap today and think back to the days where respectable soap bars weighed 5.0 oz.

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First of all, a big thank you goes out to all of the readers for making this possible. I added a Google advertisement to the right frame of this website last December to settle if I could show that advertisements can be used to generate some revenue without filling up most of the site, and it looks like you can. Some may argue that 100USD (the threshold for Google to actually pay you) in a year is not all that much, however, I never intended to make much money off this site so I am right on the mark. As for the advertisement box, I think it will stick around to see how long it takes to make the next 100. To return the favor, below are logs of earnings and traffic that other website operators judge the effectiveness of a single Google Ad unit on their site.

google_adsense-reports-daily.pdf

jan2007.pdf - feb2007.pdf - mar2007.pdf - apr2007.pdf

may2007.pdf - jun2007.pdf - jul2007.pdf - aug2007.pdf

sep2007.pdf - oct2007.pdf - nov2007.pdf

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It is important to know when to enough is enough while working on an engineering design. It is possible to keep delaying a project delivery because more and more features are added. Some may argue that adding features generally makes a product better, however, the extra features start to take away from the products over-all usability at a certain point. This is the problem of feature creep. See this nice review of the issue.

The authors of the above review make an excellent point when they point out that adding new features to an existing design often simply means putting more buttons on the front panel. They demonstrated this with a Samsung printer, however, we can see this with other ubiquitous technologies such as mobile phones. I really enjoy my Motorola Q, but my father would probably not use 95% of the features on the phone as they offer limited utility to him and require a high level of technical proficiency.

It could be a matter of adding another button on the front panel or another menu option, the result is that many products are becoming overwhelming for non-specialists. This post is not a rant, it is merely a reminder to myself that sometimes more is less. Sometimes it is better to have less features in a product and to avoid building a Christmas tree (unusable mess of wires) in the process. I guess that it could also be a reminder for the people who are trying to design the next Sony Walkman, Nokia Phone, iPod or any other gadget that will sell millions, It might be better to consolidate the user interface and offer less options rather than tacking on an another bullet point to the features list.

The image above (and below) could qualify as a Christmas tree type of circuit, but it is an ugly looking prototype where the second-generation features have been clobbered onto the first generation hardware to make sure that everything works properly.

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Somehow I agreed to lead a review session for the Fundamentals of Engineering (FE) exam, electrical engineering specialization. The lesson I learned from that experience is teaching is not as easy as it seems. This is an examination that is administered by the National Council of Examiners for Engineering and Surveying (NCEES). The purpose of the FE exam is to be the first step on track to a Professioanl Engineer (PE) certification, also from the same agency. The PE certification then allows the holder to approve engineering designs that may require safe operation. Here is some basic study material for those who are trying to cram it in the last few weeks remaining before the October test date, or those who are looking to prepare for later. Looking over the benefits and my desire to get into the biomedical field, I am now thinking about taking the FE exam in the Spring, so hopefully I can study better than I can teach.

Picture is from Theodor Horydczak’s collection of Washington D.C. in between 1923 and 1959.

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