The First Smart Air Quality Tracker?

It is now almost 50 years since the first microprocessor, but it continues to revolutionize new areas. (First MPU = Intel 4004, in 1971, which Intel designed for a calculator company!) In concert with Moore’s Law and now ubiquitous wireless two-way wireless data transmission (thanks, Qualcomm!). smartphones have become a basic building block of many products.

A companion to explain what’s in your air, anywhere. Flow is the intelligent device that fits into your daily life and helps you make the best air quality choices for yourself, your family, your community.

Source: Flow, by Plume Labs | The First Smart Air Quality Tracker

Here is a quick review I wrote of the “Flow” pollution meter, after using it for a few months.  I wrote it as a comment on a blog post by Meredith Fowlie about monitoring the effects of fires in N. California.

I started with a particulate meter (a handheld model, not PurpleAir). Now I also have a Plume Labs unit running full time. It measures PM2.5, but also PM10, NO2 and Volatile Organic Compounds (smog components).
After a few months of use, I am impressed by the hardware. It shows very sharp peaks when we are cooking or something else disturbs indoor air. Sensitivity and consistency are both high.
Another advantage is that it is very portable. It’s actually designed to be worn on your belt while commuting, to discover local hot spots. All data is GPS flagged if you turn that feature on. I think their hope is to build time/location history for many major cities, using crowdsourced data.

Accuracy is harder to assess. The PM2.5 readings are much lower than on my other meter, and are usually below 5. We keep it in our bedroom, and while we use a Roomba frequently, I am skeptical about such low numbers. Readings above 20 happen less than once a week. But as usual with these devices, because outside meters (as discussed in the article) vary so much there is no way to calibrate it against other information.

The software that goes on your phone is “slick,” but it presents the information in a very limited format. It is optimized for use by commuters/runners. If you want to look at your data differently, such as over multiple days, you are out of luck.
Price is about $180. I compare alternatives for quite a while before selecting this one. It is considerably less expensive than other sensors that go beyond particulates.

Modern smartphones now allow revolutionary advances in portable measurements and in citizen science. They have huge computational power with highly standardized interfaces for application-specific hardware, such as pollution monitors, to link to. Instrument makers now need nothing more than a Bluetooth radio to give their devices graphical displays, real-time tracking and alerting, location flagging, months of data storage, and many other features that used to add hundreds or thousands of dollars to instrument prices.

Pollution measured over the course of a day as the owner travels. This is the display shown on my phone.

“My Galaxy Note7 is still safer than my car.” No, it isn’t.

The odds of dying in a car wreck are twice as high as this thing “exploding.” I’m keeping it.

Source: My Galaxy Note7 is still safer than my car. I’m keeping it

This author does an interesting calculation, but he does it wrong. The 100 Note7s that have exploded, out of 2.5M sold, were all used for 2 months or less since the phone has only been on the market that long. When you correct for this, the rate of fires over a 2 year ownership period is roughly 1 in 1000. (Probably higher, for several reasons.)

Second, lithium battery fires are nasty, smelly, and dangerous because they can set other things on fire. I speak from personal experience. Do you want to leave a device plugged in at night that may have a .1% chance of burning your house down over the period that you own it? I hope not.

His car wreck odds calculation (1 in 12000), by the way, may be per-year, but again he does not realize that it matters. But he is right that cars are plenty dangerous. I once estimate that at birth an American has a 50% chance of being hospitalized due to a car accident during their lifetime.

There are many other TOM issues to do with this Samsung Note7 recall. Clearly they have internal problems, and problems somewhere in management.

Safety Issues for Li-ion Batteries – Reminder

I have been contributing to the comments section of this article on battery safety. Battery fires from cheap lithium-ion batteries are a genuine hazard, as I know from flying RC aircraft.

Learn what causes Li-ion to fail and what to do in case of fire. Battery makers are obligated to meet safety requirements, but less reputable firms may cheat.

Source: Safety Concerns with Li-ion Batteries – Battery University

Batteries in brand-name electronics (such as phones and laptop computers) with built-in charging systems are well made and are very safe unless physically damaged e.g.  in a car crash. But cheap batteries, which some people are starting to use in flashlights and vaping devices, are much riskier. Among other cautions, do not charge freestanding lithium-ion batteries unattended. The house you save may be your own.

Here is the site’s home page, which covers far more than safety.

Can Motorola establish a new smartphone platform?

Every electronics company dreams of starting a new platform that other firms adopt and build on. It’s one of the few paths to riches  in electronics (think: iPhone, Android, Blu-Ray, CDMA, Steam, Playstation). Check out extensive writing by my friend Michael Cusumano and his colleague Annabelle Gawer, such as this article in Sloan Management Review. (May be behind a paywall.) Although even if successful, the originator may have to make so many deals that it does not capture much rent. (Think: Android again, Blu-Ray again, Wi-Fi, 4G, HDTV, etc.) And doing it successfully is very hard, even for large companies.

moto-1935  A  related dream is modularity without sacrificing performance. This has been discussed for cell phones for many years, although in the past I have been skeptical. This article, though, sounds as if Motorola has a chance at doing both. Technically, it sounds like a good concept, if they can pull it off as well as the article suggests. Of course, technical excellence is  never sufficient to become a standard. And Motorola, with all its ownership turmoil in recent years, is not very credible. But I’m heartened to think that the goal of a modular smartphone may be technically realistic, which would be great for consumers. (It’s important that Moto is not talking about creating a new operating system or app platform. Just look at Nokia and Microsoft to see how hard that is.)

Video version of the Wired article.

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Decrypting the iPhone – some speculation

The NY Times says nobody knows how the FBI decrypted the infamous iPhone. That is certainly true, but there is speculation about physically opening up one of its chips and reading its crypto key. Years ago, I looked at reverse engineering of chip designs by  physically disassembling them. Here are some comments on how difficult this is, although it certainly may be possible.

Physically attacking a chip is an old, but difficult, method of breaking into a system that you control. In 2008, Ed Felton and others read DRAM chips that had been turned off, by freezing them in liquid nitrogen. But they were reading the outside pins of the chip package. Partly to prevent that, but mostly for speed and cost reasons, processors like those inside a smart phone now include modules like graphics, cache, and security on the same die and chip. So there is no way to read such data from outside the package, unless a design has a bug.

To read signals from inside a chip, you need to figure out the logical and physical layouts of the chip, which are proprietary and, with up to 100 million logic gates, very complex. Then you need to be able to inject and read signals with a physical separation of 100 nanometers(nm) or less. By comparison, the wavelength of light is 400 nm or greater. And the chip designers knew you might try, and perhaps did their best to make it impossible. Of course, companies still attempt to reverse engineer their competitors’ chips, so some expertise does exist.


Finally, if you are physically slicing up a unique device, I would guess that one slip and you may not be able to recover. You can’t just shut off power and start over the way you can with software attacks.

Here is one example of successfully dissecting a security chip, back in 2010. It was not easy!