Category Archives: Misc

Back from the dead

The time has come to bring microblog back to life.

I have spent the past three years working for a large medical device company in Silicon Valley designing surgical electronics. This has been a lot of fun, but I want to get back to working on open source electronics and posting about them. I have been working on a couple of designs in my spare time and have been accepted to Maker Faire 2013 to demo them, fairly excited about that. I can’t post any links yet, but watch this space for updates and hope to see you San Mateo, CA May 18-19th. I am going to try to write at least one post a week (who was I kidding?) periodically focusing on more quality than quantity. I will also keep up with moderating comments.

The end (updated)

I have made few attempts to keep this space updated and relevant over the past year, but ultimately failed. I have nearly completed my PhD so I have gotten extremely busy with finishing experiments and writing/editing my thesis. I still do analog and digital design in my day-to-day life, except, most of that work cannot be published here directly. I no longer plan on updating microblog, however, I will leave it up for at least the forthcoming months until the end of the internet in case anyone is interested in saving some information. Thank you readers, it has been a great ride!

Update: I had no idea that there were so many readers, so I will not disappoint and will do my best to keep this content up indefinitely. I may add in the future, but it will not be nearly as frequent as it was in the past.

P.S. I will be looking for an industry job in medical device design in the coming spring, so don’t hesitate to contact me if you are looking for an engineer.

Microreview: OLPC XO

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A pair of OLPC XO laptops arrived at our lab today. Given the hype and drama surrounding their debut, I decided to give them a small run through to see how usable the machine was. As the box was opened, I was very surprised at the tiny size of the device. Since this was designed for children, the size seemed fairly appropriate. The trouble started when I tried to use the device. The keyboard was about 30% smaller than a laptop keyboard and was covered with a single piece of rubber. This made the key unresponsive and made it fairly hard to type quickly. Furthermore, the mouse track pad had very poor response and was a total pain to use at points. Finally, the machine seemed very underpowered and took about ten seconds to start up a terminal without anything else running.

From a positive perspective, the laptop’s user interface was fairly intuitive and well labeled. The included video capture software worked on par with a typical 1.3MP camera phone and seemed to capture video smoothly. The device had no problem associating with our wireless network, however, there was some difficulty getting it on the VPN. The number of ports is pretty good (~3USB, audio, etc) and the battery life seems to be on par with typical portable machine. The $180 price tag was a bit higher than the $100 original, however, I foresee that the price will gradually drop as components get cheaper. Eventually adding a touchscreen would not be a bad idea.

To conclude, this laptop seems to be very appropriate for young kids. The keyboard seems like it could resist liquids and debris and the device looks durable. I didn’t see if there are any parental controls available as I doubt any parent would want to let their 5 year old sit behind a computer all day long. As for adult use, it is better to spend a little bit more money and get a subcompact laptop from ASUS or a budget laptop from Dell. The size of the machine and lack of ports (ethernet, parallel, serial) make it less attractive from a hacking perspective.

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BestBuy starts up trade-in/recycling program

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I was not too surprised when I read about BestBuy’s new official trade-in program (on Ars Technica). I figured that they were following GameStop’s lead and getting into the business of reselling used hardware. Curiosity lead me to put in my broken Dreamcast console, just for entertainment. Again, I was not surprised to learn that the broken console without any accessories or games did not have any trade-in value. What did surprise me was the option to recycle the console via BestBuy’s service at no cost to the consumer. Most of the time, it would be easiest for everyone to just find a local recycling center and simply drop off the hardware, however, sometimes there are no convenient locations. The next easiest recycling method would be filling out the form via the BestBuy service, boxing the device(s) and putting on the shipping label. The current weight limit for processing is 70lbs, however, this is definitely a step in the right direction, especially for a company that sells so many electronics. I hope that the inclusion of the recycling option was not a fluke and is continued to be honored by BestBuy. All I can say at this point is job well done.

More OpenWRT goodies

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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 ]

Accidental finding: new “greener” HDD from Western Digital

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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.

Broken hotlink code

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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.

Out to lunch

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I am going to Yalta, Ukraine for two weeks to visit my parents and to enjoy the beaches. The obvious result is that there won’t be too many posts until I return on the 27th of August. I have already imaged the next three chips for IC Friday and will queue them up with WordPress for routine publication. The chips will be the INA132, TLV2374 and X9250TC. These are a diff amp, quad op amp and a programmable potentiometer respectively. Otherwise, there may be a few pictures posted since I may have limited internet access. If anyone wants postcards from Yalta, send me an email with “Postcard” somewhere in the title and your address somewhere in the body.

I am qualified for …

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I received the formal letter today notifying me that I passed the ESM candidacy exam consisting of six hours of written exams, a written research proposal and an oral defense of the written research proposal. With the semester winding down, I can start thinking about working on some electronics projects in my spare time again. The ones that come to mind, in no particular order are:

  • telnet to RS-232 bridge using msp430
  • custom code on the NES using reprogrammable cartridge
  • adding useful features to Fonera Linux distro
  • changing the firmware on some DSL/WIFI routers I have around
  • iPod control with msp430/AVR
  • something interesting with a Peltier device
  • wind-powered battery charger

Comments/suggestions are welcome!

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