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Comment: Re:Do those require power? (Score 1) 112

by jepaton (#42453429) Attached to: Apple Files Patent For "Active Stylus" For Use With Capacitive Touchscreens

The pen for Wacom tablets is powered from the tablet itself. This is how pressure detection and buttons can work on the pen.

http://en.wikipedia.org/wiki/Wacom#Technology

The Apple patent states:

"Additionally, the sense circuitry 704 can be connected to a power source 706, such as a battery, built in the stylus. In another embodiment, power can be supplied from a power source in another electronic device, such as a touch sensing device, via a cable connecting the stylus to the device, or via inductive coupling.".

Comment: Re:Mobile bandwidth (Score 1) 261

by jepaton (#41744829) Attached to: The UK's 5-Minute 4G Data Cap

In British usage is the word usually attached to services from a utility or public service related company or would the charges listed on a restaurant menu technically be "tariffs?"

The first meaning only, so utilities and public services such as water, gas, electricity and phone have tariffs. The figures shown on a restaurant menu are merely prices, taxes and surcharges.

Comment: Re:Mobile bandwidth (Score 2) 261

by jepaton (#41742955) Attached to: The UK's 5-Minute 4G Data Cap

I'm British. I understand "tariff" to mean a system of charges. I think that the most commonly encountered use here of the word "tariff" will be in relation to mobile phones. I had never thought of "tariff" as being a government related word until now. But perhaps, the language of government has persisted from when the government owned everything. From what I understand of the word, the modern British usage is correct although unfamilar to an American. The American usage seems rather alien to me. Isn't that fair?

Comment: Re:Embedded software development (Score 1) 368

by jepaton (#37002666) Attached to: What Today's Coders Don't Know and Why It Matters

Even on slightly fancier processors you can have limited JTAG debugging support. Severe limitations on the number of instruction breakpoints and data breakpoints can limit the usefulness of the debugger for everyday work. Even in not-particularly-time-critical software single-stepping through the code can be impossible - either the bug is time dependant (e.g. errors in hardware drivers or race conditions) or normal execution relies on timing (e.g. communications). The debugger is useful only for a very narrowly defined set of bugs.

When the debug-with-printf approach is used the program speed can be badly affected. Changes in program speed can affect the occurance of the bug being investigated. Output may be going to a serial UART running at no more than 115200 baud. Even the GPIO toggling method can have this problem; the processor we use has the GPIO in a separate clock domain that runs several times slower than the instruction clock. One workaround for this is to write to RAM (if available) or to additional hardware connected to the external memory bus. At worst you're reduced to paper debugging.

Comment: Re:Really, Flash Destroyer the best example? (Score 1) 48

by jepaton (#36644356) Attached to: Dangerous Prototypes: Open Source Hardware Seeding

The Logic Sniffer is a cheap 16 channel Logic Analyser, which while no where near as good as a commercial unit comes in at 1/100th of the cost as well.

I've used an inexpensive commerical PC-based logic analyser. It had a combination of terrible software and frustrating hardware limitations (e.g. only being able to set the timebase in powers of two and a very limited number of samples).

This particular logic analyser can only make a limited number of samples. A limitation like this can make some debugging problems harder. E.g. I2C/SPI serial data where it may be impossible to trigger at the required moment. A cheap logic analyser may make sense for a private individual but in a commerical setting they are a false economy.

Comment: Re:Python for Android ... FTW! (Score 1) 243

by jepaton (#36506228) Attached to: Oracle Thinks Google Owes $6.1 Billion In Damages

The limitations of compiled executables are becoming more apparent with today's diverse hardware. One generation of mobile device may not use the same instruction architecture (processor type) as the next generation of mobile device. And the other devices connected to the processor change frequently. A new executable would have to be compiled for every major variant of the device. With something like Java bytecode the program can be one-time optimised when the program is loaded onto the device, which is a good comprise between efficiency and portability.

I program in C. In C there is normally a good correspondence between C code and machine code. But there are many ways that C is less efficient compared to more modern languages, especially when writing well structured code.

Comment: Re:Most important of all? (Score 5, Insightful) 305

by jepaton (#36055468) Attached to: JavaScript Creator Talks About the Future

Virtually every device has substantial amounts of code written in C or C++. Javascript would be useless on the microcontroller I write C code for. If C and C++ were to vanish overnight we'd be back in the stone age. I won't comment on whether C and C++ belong in the stone age, but it's great that many programmers don't have to think at the lower levels of machine abstraction.

Comment: Re:Flight Recorders are Sooo 20th Century (Score 1) 218

by jepaton (#35993778) Attached to: AF 447 Flight Recorder Found In the Atlantic

An even better solution would be a physical recorder on the aircraft and transmission of that data from the aircraft. In this way the information will be protected from either loss of the physical recorder, problems that affect the transmission equipment (e.g. aircraft damage in the region of the antenna) or problems with the ground stations. Also, the volume of data that could be logged on a physical recorder could exceed what could be reasonably transmitted continuously (because it might not possible to transmit anything after the fact).

Comment: Re:What's missing from this article? (Score 4, Interesting) 757

by jepaton (#34972810) Attached to: America Losing Its Edge In Innovation

I believe that it says more about politics than innovation that few engineers and scientists choose to enter politics. Perhaps engineers and scientists feel that they can't succeed with a well researched fact-based viewpoint against the slippery populist rhetoric of typical politicians. It's either that, or politicians have provided the ideal environment for engineers and scientists such that they feel there is no need to effect change through politics.

Comment: Re:Tracking shutting down (Score 1) 399

by jepaton (#34603434) Attached to: Intel's Sandy Bridge Processor Has a Kill Switch

The "kill-switch" is intended for businesses and governments - the cost of a computer is negligible compared to the potential cost of a data breach. Encryption should be standard for these organisations. If the encryption is done properly then it should be tied to both the hardware and the user, so that data can only be accessed on authorised computer systems. Hence the "kill-switch" which will prevent data from being decrypted (by denying access to the hardware) even if the user's passwords are known. This is far more security than the average person wants or needs.

Discrete tracking may allow equipment to be recovered. But just like anti-theft ID chips in Caravans etc. it isn't necessarily the thief that is out of pocket when the equipment is recovered.

Comment: Re:You can use katakana (Score 1) 284

by jepaton (#32516292) Attached to: Official Kanji Count Increasing Due To Electronics

One reason is the lack of sounds in Japanese resulting in huge numbers of homophones. Both Katakana and Hiragana encode each of the homophones in a fixed way unlike in English (e.g. in English "One" vs "Won"). The use of Kanji reduces the amount of ambiguity in the written language. The Chinese characters were used first anyway.

Disclaimer: I don't speak Japanese, yet.

Comment: 360 Awareness (Score 2, Informative) 166

by jepaton (#31962314) Attached to: EyeDriver Lets Drivers Steer Car With Their Eyes

Driving in the direction you are looking is a terrible idea.

Here in the UK you don't pass a driving test without using your rear view mirror, your side mirrors; and looking when appropriate through the side or rear windows. Just because you are looking for potential dangers doesn't mean you want to steer into them (e.g. a car overtaking you). Applying makeup etc. or tuning the radio would be unusually lethal.

Jonathan Paton

The only thing cheaper than hardware is talk.

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