Date: 2009-11-18 10:56 Subject: Review of the Yamaha Speakerphone PSG-01S Security: Public Tags: psg-01s, speaker, speakerphone, usb, yamaha

The PSG-01S is a USB speakerphone designed to work with Skype, giving you hands-free operation for personal or conference calling. This is part of a growing genre of products that are actually combined soundcard + speakers + mic in an external, USB-connected box. When you install it, you find that in programs such as Skype, where you can select which device will be your mic/speakers, there is now a new soundcard available on the list. This particular device is well-made, and quite compact with a standing height of 12cm, making it ideal to travel around with. Interestingly, it's also got a tripod mount on the base, so you could use it mounted high up on a standard camera tripod. The aluminium body is attractive, and it's relatively heavy, giving a feeling of quality.

In use, the device gives good sound quality. Mostly I used it at a distance of about 50cm, which gives good echo cancellation performance, but I also used it from 2m away, and was told that the voice quality was still acceptable. You could imagine using it for a small group conference, perhaps up to 8 people clustered around a table. In addition to Skype, I also used it with Microsoft Office Communicator, which also performed well, so this is perhaps a device for the modern corporate road warrior who needs to keep in touch with other colleagues. I will certainly be carrying it with me on future trips to see how well it does this task. One puzzle with OCS, was that something (whether the Yamaha software or OCS itself, I don't know) was automatically adjusting the mic gain setting, in fact until it was slightly too quiet, so I was overriding this automatic setting during calls.

I haven't yet tested this yet, but I imagine that the PSG-01S it will work with other softphones (which generally allow sound card selection) for use with VoIP, for example Bria, Xlite, Zoiper. Another question mark in my mind is about the Mac. I plugged it into my Mac and was able to use it as an external speaker unit. I didn't get it to work as a speakerphone, but I only spent about 10 minutes experimenting with it so far, and I'll have to report back later on this. In fairness,Yamahas don't claim the device is Mac compatible, but in my opinion that would be nice.

In use with Skype, I had a couple of slight wobbles. The first real call I made with Skype, the audio had a kind of "extreme dalek" effect for about 30 seconds, and then settled down to work perfectly. I took this to be some kind if echo cancellation auto-tuning process. The second wobble was a sudden "blue screen" on my Windows XP desktop. I don't know for sure that the Yamaha caused this, but this is a rare occurence with my sturdy desktop system, and of course the tendency is always to blame the last drivers installed.

One excellent feature with the PSG-01S is the use of an accelerometer inside the device to control features. This is the first time I've seen these kind of features outside of mobile phone handsets and games consoles, and in my view this really points to the future of many user interfaces. Lying the unit on its side mutes the microphone, and then standing it up again un-mutes with a confirmation "beep". LEDs on the top of the unit show you whether the mics are "live" or not. This is very nice and means you don't have to fiddle about ith software UIs during a call. Another nice thing is that if you give the unit a shake, the Yamaha control panel pops up on the PC. You can also change this to maximise volume on shake: I would like this to be more configurable so that the shake could be configured to trigger different events (for example send DTMF to mute all conference participants?).

The PSG-01S supports Windows, and is available from the Skype store for around $200. This is an expensive device, but works well, and as I said works with Microsoft OCS as well as Skype, so I imagine that many corporate travellers could justify it as a business expense. By the way, it also doubles as an external stereo-speaker unit (when laid on its side), so that's a nice side benefit for those of us that like to listen to music in hotel rooms.

UPDATE: It does work with Skype on the MacBook, although there is no console software for Mac, which means you can't configure the "shake" feature. Sounds good.

Date: 2009-07-09 15:59 Subject: Moon 40 Security: Public Tags: apollo, moon

On the 20th of this month will be the 40th anniversary of the first Moon landing, Apollo 11, famously taking Neil Armstrong and Buzz Aldrin for man’s first Moon walk.  The Lunar Excursion Module (LEM) was fundamentally a simple machine which was designed to fall to the Moon rather than fly, with one giant rocket motor underneath and some smaller attitude thrusters that allowed the spacecraft to be rotated so that the main engine could potentially point in any direction when it fired.  Control of the descent was therefore by means of a number of rocket engine “burns” that could slow the fall of the LEM.   This certainly is a “brute force” method of flying; as with Earth flying machines like a helicopter or the Harrier jet, if you have a powerful enough engine it’s possible to bludgeon the laws of physics into submission.

Later on (in the late 1970’s), the idea of landing the LEM inspired a series of popular computer games,  probably most famously the “Lunar Lander” arcade game from Atari.  I first saw versions of lunar lander in the early 1970s, running on programmable calculators, and specifically the Science of Cambridge MK14 (an early single-board microcomputer), the first computer that I ever programmed.  In the computer game, the program modelled the amount of fuel in the craft, the altitude and the speed, and of course the moon’s gravitational pull of 1.6N/kg.  By pressing a button you could “burn”, which used fuel and slowed descent.  If you studied Physics or Applied Maths at school you would have had the formulae needed to create this program, and you could even do the necessary calculations by hand.  Where the computer becomes important is in the dynamic nature of the calculations: as you burn fuel, the mass of the craft decreases, and therefore the force of the engine creates more acceleration as the flight continues. 

The real LEM had a dry weight of around 4000kg, with another 11,000kg of fuel at the start of the flight, and the descent started from a height of 15km.  Unlike the game of course, the Apollo 11 descent had two men’s lives depending on the outcome, and the flight did not go smoothly.   Armstrong famously landed the LEM (codenamed “Eagle”) with only a few seconds of fuel left in the tank, after deciding that the landing site was too rocky and deciding to fly along the surface for a while, looking for a new site.  If you’ve ever played “Lunar Lander”, you’ll know that flying along at constant height is a very expensive operation in terms of fuel, so this is a high-risk strategy.

 
The LEM also experienced some computer problems during the short flight, with the Apollo Guidance Computer giving “program alarm 1202” repeatedly, causing Armstrong to ask Mission Control whether he should abort the landing.  In subsequent analysis, the experts from MIT concluded that the computer overloaded because of the data coming from both the rendezvous radar and the ground radar at the same time.  The boffins imagined that only the ground radar would be on during the descent (to give accurate height readings), while the rendezvous radar would be used after takeoff.  Armstrong, being a test pilot, was planning for possible emergencies, and if the landing should be aborted, he wanted to be able to find “Columbia” (the command/service module) as quickly as possible as they burned away from the Moon’s surface.  You might say that the user exercised that software in the way that the programmers had not foreseen; a problem that’s still all too common in software engineering today.

I would like to think that with today’s technology it would be much easier to go to the Moon: we have faster , smaller computers;  superior materials like plastics and carbon fibre; more sophisticated fuels and engine technologies.  Certainly the one thing that hasn’t changed in the last 40 years is the courage that it would take to land on the Moon,  and we have to pay tribute to the 12 men that have done it.

Date: 2009-06-08 14:39 Subject: Burning Rubber, But Not Gas Security: Public Tags: motorcyle, race, tt, ttxgp

The Isle of Man Tourist Trophy, or “TT”, is one of the Worlds most famous and iconic motor races, where the public roads of the island are turned into a motorcycle race track.  A 38 mile (61km) course takes bikes around the island at speeds of up to 200mph (320kmh), with the fastest bikes averaging around 130mph (209kmh) over the lap.

This Friday, an important new page will open in the history of electric vehicles: the TTXGP.   The aim of the TTXGP is to build and race a zero-carbon superbike around the standard course, for two laps.  Although any zero-carbon technology is allowed, the entrants are all electric, powered by batteries; 76 miles is a long way, so clockwork or rubber-band powered is not going to be an option, and there are certain public safety issues associated with nuclear powered motorbikes, even supposing you could find a rider willing to sit on one.

Visually, the bikes look very much like petrol bikes, and in fact usually a standard road bike is the starting point for constructing the electric version.  Brakes, suspension, frame, controls are all fairly standard, but what is usually the petrol tank is now generally full of batteries.  The motors are electric, with no gearbox, and of course these vehicles are pretty much noiseless.

The electric technology looks somewhat puny in comparison with the petrol bikes, but the electric vehicles are expected to be able to reach top speeds of around 70mph.  Of course it is hoped that if this kind of racing becomes a regular fixture, then this will drive innovation in battery and motor technology.  As any engineer will tell you, you can have a hundred ideas on paper about how to build something, but the execution of building something is where the really great innovation comes from.

I’m looking forward to seeing what these bikes can do on Friday, and also hoping that this does create practical road bikes in the not-too-distant future.  An electric bike with a range of, say, 200 miles at speeds of up to 70mph seems to me like a useful vehicle for commuting.