The radio portion runs on 2V and a built-in linear regulator allows you to power it with 2.1 to 3.6V.  Since it’s a linear regulator, the current is the same regardless of the input voltage, so it pays to use the lowest input voltage possible.

Earlier this week I was working out a scheme to do this for the radio portion and the processor portion.  I thought I could save power by reducing the voltage to the processor, but it turns out the CC430 chip has a built-in inductorless switching regulator to power the processor core.  So if you lower the input voltage, the current increases leaving the power roughly constant.  This means the engineer using this part can use any supply within the allowed range without it affecting power consumption.

What more could they do to the CC430?  Could the next step be a switching power supply for the radio portion too?

This attitude of tolerance of violence toward scientists and engineers working on controversial project is completely unacceptable.  US should reevaluate its support for the Israeli government if there is evidence it condones this type of attack.

Iran claims its nuclear program is for peaceful purposes, but it is likely its goal is development of weapons.  It is understandable that the governments that have nuclear weapons want to keep their weapons but keep others from getting them.  This creates a perverse incentive for governments to want to join the nuclear weapons club.

Regardless of the politics, scientists and engineers should never be targets of violence for the programs they work on.  Eight years ago I casually talked to someone from the US nuclear weapons program about work for them.  They assured me the job was to control access to existing weapons not to develop new ones.  I suspect that was correct, although  found a different job and never learned any more about the nuclear job.  If I had worked on the project, foreign powers might have felt like I was military target, but they would be wrong.  Engineers and scientists have a responsibility to limit their work projects they believe are moral and ethical.  They should never be part of  geopolitical power games.

Photo from Fars News Agency/European Pressphoto Agency

The article was well written and held my interest, but it is really surprising that a case of geek love merits so much discussion.  It tells us how they “have trouble reading emotions and gauging social cues that others take for granted.”  It makes me  think of people who have trouble understanding the mathematical models and control loops in nature that others take for granted.

Consider some basic everyday mathematical abilities that some people lack:

• Estimating distances, weights, and volumes within an order of magnitude
• Distinguishing between open loop systems like a typical stove from close-loop systems like a typical oven
• Taking into account that the coefficient of skidding friction on a slick road is significantly less than the coefficient of static friction
• Ability to evaluate financial products such as mortgages or insurance agreements
• Awareness that the levels of most medicines in the body decays roughly exponentially
• Distinguishing correlation from causation

It’s easy to dismiss the lack of these abilities as idiocy.  It would be easy, although I’ve never heard it done in a mainstream article, to dismiss them as a neurological condition and write a cute article about the relationship troubles these foibles cause.

If we’re going to do label all idiosyncratic personality traits as conditions, hard-core salesmakers and politicians need a label just as much as hard-core engineers.  Probably everyone who’s hard-core about anything and goes out and changes the world could get a neurological label.  We’re supposed to have moved beyond this sort of thing.  We need to be skeptical of “neurological conditions” whose only symptom is minor odd behavior.

The most recent e-mailing links to a US Bank website extolling the benefits of a good credit score.  Their argument goes something like this:

We’ve developed a scoring system for individuals’ trustworthiness when it comes to paying back money.  The way to score high is to use our product.  The benefit of scoring high is you can use more of our product.  Even if you don’t like using our product, the score is being used by other industries.  We’re hoping this number we created will become widely accepted as a general indication of trustworthiness in all areas of life.  So use our product!

That’s a great deal for them.  It’s no wonder some people feel such anger toward financial institutions.  That anger is unnecessary, IMHO, because banks are not as powerful as they fancy themselves.  Their scoring system is not widely accepted, except by banks and now insurance companies.

I am not categorically opposed to a single number that attempts to distill someone’s trustworthiness in paying bills.  I’m opposed to the banks FICO score, though, because a) the scoring method is not open to the pubic and b) much of it is self-servingly based on using their product.  I find this doubly offensive when it’s presented as tips for responsible financial management.

I am positive overall on the concept of finance and have encouraged engineers to go into the financial industry if they are so inclined.  When we deal with any company promoting a product and they say “How can I help you?” we are immediately cautious they’re trying to sell us something.  Financial institutions should be treated no differently.  IEEE should not present their propaganda as tips for responsible living.

At DC this is fine.  At 2.4GHz the effect is negligible.  Between 5GHz to 6GHz, the error results in 8 to 10dB of signal loss.  If you simply scrape away a bit of the soldermask and bridge the pad to the pour, the footprint works perfectly.  It is amazing that that tiny mod results in 10 times the power being delivered to the antenna.

I suspect the reason for it has such an impact is the center conductor goes to a coplanar waveguide, i.e. a trace with grounds below it and on both sides of it.  The ground plane on the left side is connected to the ground on the right side through ground vias, but there is no path not through a via.  If there had been copper on the same layer as the connector connecting the two sides together, the missing thermal relief would not have mattered as much.

The cautionary part of this story is the length of the coplanar waveguide is less than 1 cm.  The fact that the length of the transmission line is shorter than the wavelength being transmitted does not make it immune to transmission line problems.  The entire path through the connector and connected coax is longer than a wavelength, and a discontinuity at one point can drastically effect power transfer.

This all happened years ago, but every once in a while someone new at the client asks me why we rev’ed this board, and I have to go over this infamous mistake.

If the team doing the work and the customer both understands the problem being addressed on a project, Agile Methods can handle the specification.  Usability Engineering is when someone on the team works closely with the customer to get feedback.

More complicated problems or problems that are new to the team and the customer can be modeled with a Universal Modelling Language (UML).  SADT/IDEF0 is one such method.

My understanding is SADT/IDF0 is a model of an asychronous state machine.  While it’s in a given state, the system acts as a time-invariant continuous-time system.  Every time the “state” changes, the transfer function of the time-invariant system changes.

I would love to hear feedback on whether my DSP-ish understanding is right.

The part in question is a TI switching regulator module.  When you go to the PTH08080W product page, the second sentence you find is: The PTH08080W sources output current at a much higher efficiency than a TO-220 linear regulator IC, thereby eliminating the need for a heat sink.

This is like saying the car we’re selling is much faster than a flat-bar hybrid bicycle, thereby eliminating the need to carry a water bottle.

It’s bizarre that they compare their switcher’s efficiency to a linear regulator, which is the least efficient way to step down voltage.  The whole reason to use a step-down switcher is to avoid this inefficiency, so of course their part is more efficient.  It goes on to say this eliminates the need for a heatsink, which is sometimes true, although whether you need a heatsink on a linear regulator depends on how much power your dissipating in it.

My guess is TI figures most people go to the page to scan the specs and get the datasheet, so it doesn’t matter if the description makes sense.

• I can get through quickly to a Wisconsin-based employee when I have a question.
• $35/mo for unlimited calling plus unlimited low-speed (64kbps) Internet access
• They help you set up any phone you bought on E-bay just as eagerly as they help you with something they sold.

I have been having a problem using their service, though, when I’m in a certain area of Madison.  The phone signal indicator goes up and down as if it’s trying to link to several towers.  This drains the battery over several hours.  I cannot make a phone call from this area unless I move to higher ground, where apparently I gain line-of-sight to a tower that my phone can use.

The people at AirFire are still trying to work out why this is happening.  Yesterday I was on the phone with them about this issue, and I got disconnected.

Me: I got dropped while someone was helping me with an issue.
AirFire: Did you get his name?
Me: No, I don’t think he said it.
AirFire: Hmmm… Do you want to go over your problem again with me?
Me: He had faint accent.  I think he was from California.
AirFire: That’d be Charlie.  Let me get him.
She found the correct person and put him on the phone.

Borrowing Thomas Friedman’s metaphor, AirFire Mobile is much more Olive Tree than Lexus.

I hope they can solve my problem because I think it’s something idiosyncratic, not necessarily a flaw in AirFire’s system.

“Open for business” sounds like something you say when you’re just barely functioning, as in “the building was severely damaged in the storm, but we’re still open for business”.

It also sounds backwater.  (Nothing against West Virginia, but they use the same slogan.)  The dollar-store-style sign furthers the backwater image.

The slogan sounds like something that would appeal to someone who a) is not formally educated, b) worked mostly in government not business, and c) knows business is very important but does not understand how it works.

The bizarre thing is that Wisconsin already had a good brand image of good work ethic, good values, and stoicism.  Wisconsin was specifically mentioned as a good place to locate a shop in the book “Execution: The Discipline of Getting Things Done” for these reasons.  We should be building on this already-existing image instead of something taken from an off-the-shelf sign.

If computers could replace almost all human jobs, it would be a good thing because that would mean we could have the same goods and services we have today without human work.  This is something people have dreamed about since time immemorial.

When the industrial revolution started, it meant people theoretically could work much less and have the same lifestyle they would have had in agricultural economy.  They could spend the rest of the time relaxing with their families.  Instead, though, society chose to keep working and produce way more goods and services.

Something similar happened when we went from a hunter-gatherer society to an agricultural society.  We may be seeing something similar today going from an industrial society to an information/automation society.  If it plays out the same way, the amount of goods and services we can produce will continue to increase.  We are right to be asking the big questions of how we want that go forward and what we want to do with our new-found production capabilities.