Stephen first set off on his mountain bike to begin his Global Cycle Challenge on the 18^th February from Greenwich Park, London. Since this date he has cycled through a vast number of countries (including, France, Spain and America) crossing the halfway mark in New Zealand in mid April, however, luck did not seem to be on Stephen’s side.

After dealing with various injuries (including Achilles Tendonitis) and broken equipment he was finally forced to withdraw from the Challenge on the 13^th May after becoming sick from an illness that left him feeling “too physically weak and tired to continue” when crossing the Australian Outback. He managed to make it into Perth and reached Singapore on Saturday 12^th May, but unfortunately felt unable to continue with the Challenge and is returning home in the next few days.

Class-D amplifiers are known to have efficiency advantages over linear amplifiers, (typically 90% versus 50%) but have a reputation for lower quality sound, especially if the PWM frequency is not sufficiently high. Digital Class-D amplifiers are likely to be particularly poor when implemented without feedback unless the Power Supply Unit (PSU) is almost perfect, and the high power switching output stage is distortion free; this is never achievable.

The DDFA solution
The solution to these problems is a feedback loop, which can correct for errors introduced in the various power processing operations (output stage, reconstruction filter, PSU), but this is a difficult task in a digital system. DDFA uses a patented high speed and very accurate feedback system, which measures the error in the power switching output stage, conditions the error signal, and then feeds it back into the digital domain to correct for the error at the output. Correction of the switching errors allows a higher than typical PWM frequency to be used, improving the output filter performance in the audio range. The information in the error signal can also be used to infer the output stage operating conditions, and therefore provide control to protect against short circuits.

Performance- What do the specs tell you?
DDFA amplifier specifications quote two key figures: Signal to Noise Ratio (SNR) and Total Harmonic Distortion (THD). Whilst the numbers may not give much context to non-audiophiles, the important feature of a high SNR is the complete absence of audible hiss or hum from the speakers. This absence of background noise gives a large dynamic range, allowing in turn high detail in the reproduced sound with good definition of individual voices and instruments. The importance of a low THD is to give a neutral, clear and uncoloured sound, as close as possible to the original performance.

Digital advantages
Today, most sources, transmission paths, and storage are now digital. Using a digital amplifier removes the need for extra conversion stages from digital to analogue, and so keeps cost down and quality high. For CSR, with our range of wireless products, the interface advantages are clear.

Adding extra signal processing for room correction filters or correcting for the acoustics of a more compact product are easily done within the DDFA digital domain; enhanced audio experiences, such as virtual surround sound, and Dolby or DTS decoding will be offered soon with CSR companion devices, and will be fully integrated in future products.

Scalability for a range of applications
The existing DDFA solution provides up to 8 channels of amplification, using external power devices. This allows amplifiers with a wide range of power outputs to be implemented e.g. 20 Watt to 200 Watt per channel.  The priority for future products is for more integration, reducing cost and Printed Circuit Board area.

The multichannel architecture, rich processing feature set and digital interface suit a number of application areas; channel counts of future products will be directly matched to growth area products such as active speakers (wireless and wired), sound docks and soundbars.

Kindly provided by:

David Jones
Senior Applications Engineer, Voice and Music

The Mi-Zone proximity alarm is a unique device that can attach to anything considered worth protecting.  Users can simply attached it to, or hide it on, anything they wish to safe-guard.  Once the selected item moves outside a pre-set security zone, the alarm is triggered on both the mobile handset and the Mi-Zone tag itself.  You can choose from low, medium or high security settings, depending on the range of the security zone you create around the item you are protecting.  

CSR Bluetooth technology sits at the heart of the Mi-Zone proximity tag.  Mark Aubin from our Home Business Group has been working with Phil Jarrett and his team at Mi-Zone over the recent months. Mark introduced Mi-Zone to Asda and Tesco at Mobile World Congress in Barcelona this year where the product was met with a very positive response.

Look out for the CSR branded tags which will be on sale in leading retailers including Carphone Warehouse and Apple stores in the coming weeks.

You can access an interview with Phil and the BBC here to learn more about how Phil brought his product to market and how he secured funding from the Irish government.

Kindly provided by:

Mark Aubin
Director of Marketing Development

Both of them were team efforts.
Chris Church won for Outstanding Technical Contributor.  The team involved in this supported each other as follows:

• Robin Heydon did the original work, and supported Chris technically.
• Chris Church stepped up and assumed leadership of the Human Interface Device Working Group.
• Krishnan Nair made technical contributions.
• Members of our team (Simon Finch et al) provided real hardware.
• Chris had to get through determined opposition from within HID, and from parts of the SIG.

 CSR also won for Outstanding Profile Tuning Suite (PTS) Contributor.  Chris accepted on behalf of CSR.  Here are a few points to note about this award:

• We have provided the reference hardware for PTS for a very long time; thanks to the product teams.
• Nigel Hall keeps the PTS team current with firmware updates on that hardware.
• CSR people (e.g. Magnus, Joe and Rasmus) have made ongoing technical contributions to the PTS design.
• We have overcome recent supply chain issues to keep the SIG PTS team happy.

Congratulations to everyone involved with these awards!

Kindly provided by

Joe Decuir
Standards Architect

White space is the buffer space left between signals to prevent the interference that causes the buzzing noise you hear when your phone is too close to a speaker.

Consortium members are keen to examine the potential of these white space wireless networks to improve wireless quality and coverage, especially in areas where coverage is not strong at the moment.

Five different areas were used in the trial. The test that CSR oversaw, led by Les Smith, (full report here) took place at the ADC theatre in Cambridge and set out to define the regulations required by UK and EU governing bodies to ensure white space can be used alongside existing systems. He concentrated on managing the white space whilst at the same time protecting the theatre’s licensed PMSE equipment (Programme Making Special Events).

The high profile nature of PMSE events (The Olympics, Live Concerts, Film, TV and Theatre Production) mean that he had to address all of Ofcom’s concerns and whether there would be any implications to paid licensed devices and customers. The results showed that if a database could be set up to administer the WSD (White Space Device) power, they could transmit without interference and the WSDs and PMSE equipment could co-exist successfully.

Re-writing Standards
The findings were presented and discussed the impartial engineering expertise and advice CSR could provide. Currently the regulations slightly favour PMSE so the importance of being involved and able to represent future developments in white space from an engineering perspective in this, its early stage, is vital to its whole future development and possibilities.

Ofcom have agreed to rewrite the whole PMSE protection section for the proposed EU standards and Les has been invited to present his findings to the ETSI Committee (European Telecommunications Standards Institute) and will assist in the rewriting of the SE43 CEPT ECC (Electronic Communications Committee) Mandate.

Other whitespace tests were of city centre coverage in Cambridge, where whitespace device (WSD) base stations (BS) were setup all over the city in four pubs and a theatre. The aim was to provide widespread coverage including “pop-up” Wi-Fi hotspots. This was a success as users were able to enjoy data intensive services such as online video streaming from Sky Go and the BBC iPlayer.

In another test a base station was installed at one of the consortium’s headquarters in Melbourn, Cambridgeshire and linked to a household in the nearby village of Orwell, where residents experienced vast improvements to their broadband service with speeds of up to 8Mbps over 5.5 km links.

There was also a Machine-to-Machine (Internet of Things) test as the prediction is that by 2020 there will be 50 billion connected devices and a good proportion of them will be connecting wirelessly. The Internet of Things will also use available white space. An example is where silicon chips have been installed in bins to let the council know when they are full.

At the Imperial War Museum in Duxford Nokia and Spectrum Bridge demonstrated a special application which sent smart phone prompts with tour information including facts and video clips to museum visitors.

What does all this mean for the other technology that CSR is helping to pioneer? You’ll have to wait and watch this (white) space!

Kindly provided by:

Richard Edgar
Senior Product Manager

After leaving San Francisco on such a high I could be forgiven for thinking such good luck was going to continue. Instead New Zealand has been a major struggle.

I arrived at 5:30am to a waking Auckland, not too cold and the sun was beginning to rise. Clearing customs was extremely relaxed and I collected my baggage without problems. That is until I looked at the box closer.

USA customs had again decided to open my bike box as an apparent security risk only they opened it with a knife of some sort, slashing both my tent and sleeping mat!
During the handling process the rear brake had been badly damaged and needed 3 hours to straighten and part of the cycle had been forced through the box suffering yet more damage to the frame. An expensive rear light bought in the USA had been smashed which meant no riding after 6pm!

Bike finally built and a mental note made to complain I set off from Auckland airport heading south. 70 miles that day was all I could manage, probably because of the 13 hour flight and a stiff neck from sleeping on the plane, but also still extremely wound up. Auckland is also difficult to try out of.

I stopped at the town of Huntly in a motel where I found fresh fruit in abundance and away again at 6am the following morning through Scottish named towns such as Hamilton and completing 130 miles to National Park home to 3 of the North Islands volcanos one of which is still active.

This was uphill all the way and was later to cause me problems with fatigue.

The following morning I set off again at 6am. It was icy on the roads and it was the coldest I had been since France. Within a few miles disaster struck when a number of minor issues coincided to cause a potential disaster.

A long quiet road, a single cyclist (me) a single pot hole, one GPS and a truck all combined at the same time resulting in a smashed GPS unit with all my maps on.

Not a happy man especially when I had to make Bulls that day another 130 mile ride.

Bulls was made by 6pm! Its a town which makes light of its name and in doing so has become a bad joke. The police station has Constabulls written on it and Bulls declares itself a town like no udder. Well you get the point.

My final day in North Island was a flat 80 into Wellington and the last ferry across the Cook Straight. Apparently one of the most beautiful ferry crossings in the world a night crossing does not do it justice

However morning in Picton bought stunning views of the surrounding islands.
This day was tough still recovering from the flight and long mileage, I was forced to cycle into and through the night covering 200 miles into Christchurch in a desperate bid to make Dunedin. However the reverse was true and I was physically spent by the time I arrived with still 250 miles to go to Dunedin airport.

I should have allowed longer for New Zealand with all the climbing and I’m both physically and mentally exhausted again so I’ve rested up in Christchurch where I’m hoping to recover and source an essential replacement part which if it broke could leave me stranded in the outback! So far I’m not having much luck.

Next stop Australia and the Nullabor an 1100km outback plain where I will truly be on my own.

Happy cycling

Steve

Having returned from near oblivion and self doubt I have amazed myself at how well I have done considering my injury in Athol.

I promise I tried to stick to Physio’s orders of 80 miles a day but the warm weather, sun, desert scenery along with the odd ghost town spurred me on and I made the distance between Phoenix and San Francisco four days ahead of planned schedule.

I really have to thank CSR Cambridge for putting me up in San Francisco for a few days and as I prepare to fly to New Zealand I am renaming it Cambridge Silicon Radio Land.

Some fantastic sights were seen as I cycled. Cycling through sand storms, Dust Devils spiraling upwards in sand filled skies, cycling over Big Sur mountain, seeing whales leaping from blue seas off the coast near Plasket and moonlight over Malibu.

Lets not forget though as romantic as it all sounds there are accompanying stiff legs, strong winds, sun burn, smelly socks, unshaven face, uncut hair lack of deodorant and rashes you don’t need to know about!

I love it!

San Francisco saw me visiting some cult locations around the Bay area. My favourite film of all time is Bullitt with Steve McQueen. To drive that famous car chase scene was a dream come true.

Then another came true! Marin Mountain Bikes HQ is at San Fran, I have always used their bikes so it was them that really got me into this challenge and visiting their HQ was like…Mecca.

They actually gave me a leather belt with a solid brass buckle featuring their logo engraved on it. Guys you are gods.

As I type I am sitting in San Fran airport waiting for my flight to Cambridge Silicon Radio Land where a milestone awaits. I will be exactly halfway around the world and technically heading home although some hard cycling awaits not least India. I’m sure some surprises wait for me there.

Happy cycling

Steve

It has been some time since my last update but with good reason.

I left Portugal suffering from both food poisoning and Achilles Tendonitus however a few rest days in transit between Europe and USA saw my heel improve and the worst of the pain was over. Or so I thought!

Upon arrival at Boston I was met by the guys at Burlington and bright spring like weather.

Boston is a picturesque city with charming New England look. Some of the homes date from the American war of independence and are still in the same family and everywhere makes reference to past colonial times but surprisingly it feels more England than anywhere else with names such as Cambridge, Norwich etc.

The following day started well with a short ride with some of the guys before finishing off a round 100 miles during which I was ‘redirected’ by state troopers having strayed onto Highway 2 instead of Highway 2A, and finally arrived at Athol M.A early evening just as it was getting cold. I stopped in an Inn called Prince Philip where I chatted with the locals about what I was doing and still trying to answer the WHY? question.

The next day was disaster. Shortly after setting off I had an accident. Having departed early I was making good progress and descending from Atholl at good speed when my wheels slipped on melt water covering wet rail tracks. The result was instant and down I went before I could even say “oh”. Being clipped into the pedals my ankle took the full force of the fall and further twisted my Achilles tendon aggravating the injury again. Michelle the CSR Plc Battle bike was scratched and the rear panniers damaged. I managed to limp to the University of Massachusetts where a bike shop fixed my panniers within minutes, shame they couldn’t fix me. I spent the next two days trying to recover and figure a way forward. Several ride attempts were made but unfortunately I just couldn’t put any weight through the ankle.

This left me with a significant dilema, do I stay and hope for a quick recovery while paying medical bills etc, do I try and move forward using public transport? Unfortunately public transport in the USA is not geared for cyclists and the costs were prohibitive.

Rather than spend money on hotels and expensive doctors I made my way home where I visited a physio. I was gutted when he informed that I should be off my ankle for 6 weeks! I had a small tear to one of my tendons.

What do I do? Chances like this are once in a lifetime chances and so many people were behind me with this challenge.

Three weeks later a combination of ultrasound, heat and cold and massage saw me recovered enough to return to the USA! My Physio is next to Queens and Presidents and when he gave me the news everything lifted and it was like being reborn.

I flew straight back into phoenix Arizona to warmth and longer days with strict instruction from my Physio to limit my rides to 80 miles for the first few days and also wear shoe inserts to reduce stress on the tendons. A visit to a baseball game and a small beer saw me fired up to begin racing again, and that’s exactly what happened.

Leaving Phoenix on the 30th March saw me crossing the desert through sand storms and sheltering overnight in a deserted ghost town of Desert Centre before arriving in Palm Springs California where I spent the night with fellow cyclists I had met on the road between Phoenix and Blythe California. Head winds and lack of food and water stops made going tough but I reached my target mileage most days and on others exceeded with distances in excess of 100 miles+.

Since then I have cycled along the California coast highway known as PCH1, climbing over mountains such as Big Sur where I saw Whales leaping from the blue seas of the pacific ocean and Elephant Seals basking on long beaches. Out to sea I could see a storm brewing which while giving me a tail wind was also warning me of wet weather in Sunnyvale and on my ride into Sunnyvale I was confronted with the wettest weather yet while climbing over the Santa Cruz mountains from Watsonville. Part of my route included Highway 17, probably the most scared I had been on a bike on a road. Another diversion by patrol officers saw me practice my cross country riding skills where thick mud clogged all my moving parts up and left me soaked and mud strewn for my arrival at the new Sunnyvale CSR office. And what a welcome it was with hot coffee and people with lots of questions. I in response left a nice big puddle on their canteen floor!

So things are now looking good, my mileage has climbed back up to 130 miles (sorry Doc) and as I write this I am now in Sunnyvale where its not quite so sunny.
Next stop is New Zealand which will be a form of milestone where I reach the second Antipodal point on the globe. In effect although there is a huge amount of cycling still to do I am on my way home!

Happy cycling

Steve

Stephen Phillips makes it to Santa Ana, CA from Phoenix, AZ in four days! Steve arrived into Santa Ana at 8:10PM on Tuesday 3rd April and headed straight for the Hampton Inn to rest up for the night before biking into CSR Santa Ana on Wednesday 4th April. He arrived at our office around 9:00AM and met with some of our engineers, reliving his tales on the road in this race and several others he has participated in. We had a gourmet pizza lunch for him with the group. After lunch, Steve and I (Soo) went to get one of his wheels repaired, it needed new spokes and a new reflector. Then we headed off to Huntington Beach, “Surf City USA,” the epitome of California living – beach, sun, and a laid back lifestyle. It was a beautiful day too, 75°F, perfect SoCal weather. Afterward, Steve and a couple of us went to eat AYCE (All You Can Eat) Korean BBQ so that he can refuel on protein for his next journey to Sunnyvale!