Tuesday, 22 October 2013

Glow in the dark path in Cambridge - Starpath from Pro-Teq

Here is a news article on Cambridge's new glow in the dark path way. It is used in Christ's Pieces.

Press release is at end of this post, indicating the glowing surface technology is patented.
It is claimed to be the first  ultraviolet  powered path, but has anyone seen it work?

Here is the manufacturer's web site, Pro-Teq.

Here is the video from the Daily Telegraph.

click to enlarge.

The patent referenced  on the web page in the bottom left corner  is: GB2472474  as here. (Depending on your browser font size, this patent can be hidden in error.)
The patent documents and history are here. I read the patent  and could not find any method described or claims to creating the glowing path.

image from Pro Teq

So, how were the above pictures taken showing the glow?
You can see that the image above shows a  picture of a moving cycle lamp, taken over several seconds. This very long exposure allows the ultraviolet  particles to be visible in dim light - to a camera. Five trusted people I know have looked at the path in the dark, seen darkness  and wondered if it worked.

Natural minerals that glow blue in the dark include fluorite and others as here. 

from stuff.co..nz - click link for more

I communicated with the inventor, Hamish Scott,  this morning and there is apparently  now no patent with respect to the glowing path, (contrary to press release below)  but just  photo luminescent particles, a natural earth product,  sprayed on the path. The ultraviolet is absorbed in the day and emitted in the dark. A very impressive design.
  I am waiting to hear what the actual substance is as we need some in our street being pitch black in our corner at night!
Starpath costs about £75 a square metre to apply. 150 square metres were covered in total in Christ's Pieces giving a total cost estimate of £11,250.

 Starpath  is similar to COREglow here. COREglow can also be provided as photoluminescent aggregate set in tarmac and glow for hours.

We can go to Amazon UK and buy these Coreglow  glowing rocks.

image from Amazon 

I will update my blog when more details revealed from Pro Teq. Update, no replies from Proteq as of 1/11/2013.

Press Release.



Pro-Teq Surfacing UK Ltd, light the way with their innovative re-surfacing methodology demonstrating how STARPATH could help City Councils around the UK recognise the potential savings in local and national government energy bills.
STARPATH could be an alternative to street lighting.

SURREY - - 17 October 2013 - - Pro-Teq Surfacing (UK) Ltd, developed and patented a world first for spraying a liquid based product in combination with either soft or hard media. This innovative pathway re-surfacing methodology called STARPATH is the result of an extensive period of chemical trials. Comprising a multitude of product samples, mix ratios and application techniques. STARPATH is currently being trialled in Christ’s Pieces, a well-known park in the east side of the centre of Cambridge by Cambridge City Council.
This product is extremely cost effective to both install and maintain while its seamless surface may be applied to any existing surface, be it concrete, tarmac, timber or any hard stand substrate (solid base). The aggregate material absorbs and stores energy from ambient light (UV rays) during the day, then releases this energy at night allowing the particles to glow (see picture attached and link: http://www.pro-teqsurfacing.com/playvideo.html for video reference).
Pro-Teq Surfacing (UK) Ltd believes STARPATH has considerable environmental appeal beyond the obvious reduction in council bills. As a resurfacing technique, which does not require the existing surface to be removed, the Pro-Teq alternative has immediate advantages over those products offered by its competitors, including savings realised through carbon credits, reducing the council carbon footprint. It eliminates the substantial cost of removal and disposal of the existing surface, ultimately enhancing the ‘green friendly’ reputation of those organisations choosing to install Pro-Teq’s products.
Hamish Scott, Owner of Pro-Teq Surfacing (UK) Ltd said, “There is nothing like STARPATH in the world, this product adjusts to the natural light, so if it is pitch black outside the luminous natural earth enhances, and if the sky is lighter, it won’t release as much luminosity – it adjusts accordingly, its almost like it has a mind of its own. It is exceptional. At Pro-Teq Surfacing (UK) Ltd, we use natural earth products and it cannot be replicated by any other source; you need to physically see it to believe it, this is pure nature doing its work”.
As outlined above, STARPATH effectively generates its own energy during the day while radically enhancing visibility at night, which assists pathway users. It is certainly a sustainable surface, perfect for cyclist and disabled access and has a high safety margin with its anti-slip properties. It can also help to reduce the risk of collisions between cyclists and pedestrians at night without having to resort to artificial painted centre lines. The aggregate is a non-reflective light source, the lack of any glare off the surface further enhancing its acceptance in more populated areas. (eg: if this product were to be laid on a driveway in a private residence, there would be no adverse impact on neighbouring properties).
This product has recently been sprayed onto the existing pathway that runs through Christ’s Pieces open space, Cambridge between the city centre and the Grafton Centre, and is used by pedestrians and cyclists during the day and night.
The Cambridge pathway measures 150 square metres, took only 30 minutes to spray the material on, and the surface was ready for use less than four hours after the job commenced. This short installation time allowed minimal disruption to the public.
Hamish Scott believes STARPATH is more than cost effective for councils, as councils around the country are currently turning off street-lighting at night to realise energy savings. STARPATH provides a viable alternative, which provides for safety at night, whilst also being cost effective.
Hamish Scott said, “Councils spend significant sums of money fully replacing existing pathways when the existing surfaces have reached the end of their practical life. Our product is cost effective, fast to apply and fast to set, is an anti-slip surface, while the client has a choice of size and colour of aggregate. Once the aggregate is laid we apply a finishing coat, which is specially formulated to ensure the surface is water-resistant, and provides longevity to the finished product. Further, the surface is environmentally-friendly and aesthetically pleasing”.
He continued, “We are so pleased Cambridge City Council has agreed to trial the product. STARPATH has attracted much interest from the public, in Cambridge and other councils in the UK. We continue to refine and adapt the product to ensure it meets the on-going needs of our customers and the environment”.
It seems Pro-Teq are ‘streets ahead of the rest’ and are clearly welcomed by many. Pro-Teq has earned an outstanding reputation for repeat business from key customers, primarily because its customers recognise there is a significant technology and environmental gap between Pro-Teq products and more traditional resurfacing options.
Pro-Teq’s website details how it’s re-surfacing solution works, and the technology behind it, the website also includes a photo gallery showing its portfolio and a short video demonstrating the Pro-Teq team at work.

Monday, 7 October 2013

At last! low cost wireless sensing for couch potatoes.

Update 9/10/2013

Texas Instruments SensorTag 

Wireless sensing or The Internet of Things has been around for a while but at last we have a multisensor  device for £25 . People have designed many wearable health and sports monitoring  applications, initial research by me at Microsoft in 2001, so  below I cover some new useful designs for busy couch potatoes, including The Door Monitor, Watch My Cooker, Cat Burglar Alarm and finally Am I Alive? It looks like these can be practically built and tested and used by people with Smartphones. 

 Nov 2012 Texas Instruments  announced  a multi sensor wireless device  (6) for  £25, inc shipping and tax with all the hardware sensors included. This looks like a loss leader price for development purposes  but will be delighted if can stay at this price. I have seen many sales promotions for this but not sure how many shipped as not many third party apps on the web.  I am due to get  received one on  7/10/2013.

  This devices makes obsolete many other wireless sensor hardware designs. I will be very pleased to start creative programming on  it  without worrying about my hardware design issues such as eyesight,  wires falling off, batteries, antenna design  etc.  
Texas have done a great job with this design, A SOC with built in Bluetooth and  8051 8 bit microcontroller for low power, and also the heavy duty signal processing  is done on the smartphone device. The CC2541 SOC is around $3.08  in 1000 off quantities, i.e. the Bluetooth and microcontroller but no sensors. At this price, a design can be made disposable.

CC2541  6 x 6 mm

From  the Texas Data sheet, click to enlarge.

It can be used with low energy Bluetooth e.g the  iPhone.

Here is the spec. 


  • Humidity Sensor
  • Pressure Sensor
  • Accelerometer, 3 Channel, up to 14 bit resolution 
  • Gyroscope
  • Magnetometer
  • 2 contact switches 
  • Bluetooth low energy, range 50 metres. 
  • Radio Signal Strength transmitted so useful for location services.
  • CR2032 coin cell providing months or years of battery life. 
  • There seems to be  no Time Of Day clock but this is provide by the host computer. 
  • 32KHz sleep timer
  • Missing is a low cost light sensor but could reverse bias a LED to measure light level.
  • GPS not need as you need to be just a few metres (50m)  of your smartphone to read the wireless data.
   size 71.2x36x15.5 mm   57x25x1.5 mm (PCB)  

You will find most  the above sensors in smartphones but remote sensing has many more applications. 

All I will add at first  to the hardware for my designs  is a neo magnet for attachment to walls etc. Modern homes have steel pillars in unexpected places e.g.  hidden behind the plaster. 

I also require a waterproof version and the PCB and a larger battery will fit inside a  35mm film cannister  ( internal  64mm in height and 38mm diameter). Buy from eBay.

Here is a teardown.


Texas and others cover many of the usual wireless sensing designs including sports applications, games controllers, wristwatches  and  the perennial lost key detector. Below are some new ideas  for couch potatoes. 

 The  Door Monitor

After I have learned how to program the SensorTag, the first object I will attach it to is my front door, with messages sent to iPad. 

 Yes a camera can be used but also useful to have simple text alerts sent to your smartphone, tablet, etc. 
  • The thermopile will detect if a  person stood at front door.

Field of view from Texas Data sheet
  • Accelerometer/gyro  will send message re door open or closing. Accelerometer can detect vibration off a door knocker, useful if hard of hearing. Gyro can detect opening and closing of door. 
  • Will the magnetometer be sensitive enough to detect the the steel from a visitor's parked car 6 feet from my front door?
  •  The humidity/pressure  sensor gives current alerts re rain, so we don't let our washing get soaked on the line. 

Watch my Cooker - Kitchen Safety and Dementia.

 The Sensortag.  has a thermopile for measuring heat at a distance,(-40C to 125C)  ALSO humidity, steam  so can point at gas cooker hob and message sent to ipad/iphone if pots boil over. Useful for forgetful cooks, Alzheimer's and dementia. 

None contact temperature sensing using thermopile, 68C. 

Adding a Sensortag to a fridge door provides the imagination with many uses, such as diet control and care of people who live on their own. (if you don't open a fridge for a while, are you well?).

Another Pet Project - Cat Burglar Alarm 

I might write something simple to test it with like cat burglar alarm, 50m range to ipad. Using the wireless accelerometer , can use direction to count N cats IN and OUT on cat flap, and if N+1 IN counts,  it implies it  the neighbour's big cat!  Saves me getting up at 5am to sort out cat fights and who steals the food at 3am. (My cats sleep  upstairs). 

It wasn't me!

And finally, Am I Alive? Wireless accelerometers useful for fall detection on people. They really need to be small enough to add to devices like spectacles (thank you AM for this idea) so people wear them all the time. An accelerometer can also be worn on the chest for respiration monitoring, so the SensorTag may be applicable.

Saturday, 21 September 2013

How to get a seat on an overcrowded train using real time sensing?

Kings Cross London Railway Station 2012

I wondered if there was a smartphone app to indicate if the train I am about to get on to London from Cambridge  has a seat or not. I do not know if even our rail network at Cambridge train station counts the number of people who get on each train.  Booking of seats is very unreliable as customers ignore the booked seats.  There will be no solution to train overcrowding in UK in the near future so perhaps a phone App to help?

 I used Google search and typed in train overcrowded accelerometer. I used the search term accelerometer as this can detect if person sitting, walking, etc.  Nothing relevant appeared. There may well be an obscure academic article on the subject, but is did not appear,  but I really want an App to use  or design now. It is really uncomfortable standing for a hour on the train. I used to commute to London in 2012, but severe backpain caused by standing (no seat on train)  and not walking, and other issues forced me to stop.  You won't get many people offering you seats on this London train, even a young man with crutches was forced to stand, nobody gave him a seat. We can sit on the floor but it is very dirty.  We paid (2012) £36 + London underground + £8 parking + travel + coffee to station for a daily Cambridge to London commute, with no guarantee of a seat.

Here is a theoretical  possible method of calculating if people are sitting or standing using motion sensors built into phones. Android has been successful in aggregating or crowdsourcing  GPS location signals from thousands of anonymous smartphones in vehicles to determine real time  traffic jams and can then update Google Maps with traffic data. In Jan 2013 there were 36 Million Smartphones in the UK.

There is an App re train overcrowding but it is not automatic and relies on users typing in data on overcrowding.  There is yet another another App but it is based on train length and historic data, not real time overcrowding, what percentage of  people standing or sitting?   Google will also know where crowds are congregating re their Andriod GPS data. If we use sensors such as accelerometers and temperature sensors perhaps a better guide to train seats available can be provided?

 I thought it might be useful to aggregate peoples' physical movements on a train to determine if seated or standing and so give an indicate of chance of a seat. The GPS location is known, the train time is known and people could share their data via an App or even the background data that Google always collect, see below:

 The method of determining the physical activity of people  has been well proven using accelerometers and many sports/life logging applications using sensing.  I did some initial research in 2000 for Microsoft on this and more of my research on human motion sensing is here. The activity of sitting or standing can be determined by changes in acceleration as in graph below.  People will be holding their phone some of the time, so a need to filter out the relevant sensor signals to determine if seated or standing.

Microsoft  2001 SmartMoveX sensor on the body

Android app with x,y,z, accelerometer data. the blue trace at zero shows sitting down, green at zero shows standing 

The latest MEMs accelerometers have progressed a lot in the last few years. They have a 3 axis output, up from 10 bits to 16 bits output, 1.8V interface. They can have a built in state machine that is programmable to compute actions to detect  free fall, wake up, pulse counters, step recognition, click, double click, shake double shake,face up/face down, turn/ double turn.(data from ST Microelectronics) These all used to be needed to be programmed into the main computer for the phone.  Here is an example LIS3DSH  from ST.

Image from ST Microelectronics 3 x 3 1mm package

The iNEMO-A device from ST combines an ARM microcontroller and 3 channel accelerometer into a 3 x 3 x 1  mm package. There are now devices that combine accelerometers, gyros and magnetic sensors on one board. 
Here is the accelerometer used in the new Apple 5S from Bosch.

If the customer was standing at the train station and message as below received, would we find this useful?
Below are  text message and  Twitter simulations.

My 360 degrees panorama of Kings Cross Station. shows the customers waiting at the departures gate waiting to see the arrival of the Cambridge train. (Spot the headless passenger!)  Everyone then gallops  to the platform so they can get a seat on the Cambridge train!

This Kings Cross Departures Board is missing essential information, such as the current time (!) and is there seating?
I will be interested in your comments or even if there is an app that can help. If enough people interest I will find a team to write the software.

(c) Lyndsay Williams 2013
email: sensecam@gmail.com

Saturday, 7 September 2013

Saving energy, new fridge design based on a freshness sensor

Sometimes the best inventions come when we forced to a deadline or threat. A Microsoft manager used to say to me, if a "gun was placed to my head", how would I solve the problem, (in one hour). This worked very well in focusing the mind when I worked there.
 Moving on to 2013, I was approached last week with a 2 day deadline  on grant application (£50k) for "Green" issues, reducing carbon footprints,  and saving power in the home, a perennial problem with many people seeking solutions. Could I design something?  There are numerous government grant offers for solving these problems. The incentive is getting a grant to design some useful technology for society, getting it manufactured  and get paid for delivering a  result, e.g. a working prototype.

I have some research experience in smell research as here.
I am also fascinated by the sense of smell of our cats and dogs.
So this blog is an excuse for a picture of my cat Dot's nose after her mouth surgery in Feb 2013. More here about the cat's Jacobson's organ.

Click to enlarge

One idea of  interest is saving power in the home, with appliances that are switched on for 24 hours per day, e.g. our fridge. The fridge design needs a rethink to save power. Why do we have a fridge? It is not just for cold beer and chilled wine !
We need our fridge to preserve fresh food food, stop bacteria growing, and to stop food poisoning. We are advised to set our fridge to 4 Centigrade (40 Fahrenheit)  for these reasons. However this low temperature can kill  the taste of, for example fruit,  a top chef told me not to store tomatoes in a fridge, so I have not for many years. We can test for food passed it's best buy date by smelling it.(Don't trust me on this). What if you are a vegetarian, you may not have animal produce, do you need a setting of 4C ?   So we could design a fridge with a gas sensor to detect freshness,  rather than temperature sensing and maybe fridge temperature a bit higher and so save electricity? The modern  gas sensors can detect gas  to 1 Part Per Million (ppm) the start of  decaying food by measuring the ammonia, hydrogen sulphide, methane etc of food that is starting to putrefy. Enjoy this Wikipedia article on decaying food. There are new optical gas sensors but also the low cost traditional gas sensors.
The sensing of imminent decay can be used to control the temperature. A microcontroller can measure the gas level and provide an audio link or control to an external mains controller for the fridge.
The food obviously needs to be unwrapped for the gas sensor to work, but this is fine as sometimes the forgotten piece of unwrapped food in the back of the fridge is the culprit.
Some people do not have a sense of smell and this sense also fails as people get older.
Re the power saving, if we can keep our fridge at 12C (perfect temperature for some white wines?) and our vegetable retains some flavour, this all contributes to saving power in our fridges.

My warm salad, smoked salmon, olives, and tomatoes 

The engineering design with a microcontroller should be routine, gas sensor samples every hour or so so an AA battery should  last a year. We can add temperature measurement. We can measure how full the fridge is by an ultrasonic echo sounder, (full fridge, but not overloaded is more economical). An audio alarm for when the fridge door has been open too long for viewing?  I feel the call of programming an Arduino again...

And yes, radio signals (to the mains controller if needed) do work transmitted into and out of a fridge, I tested it on my mobile phone.

This may be more of a research project, a possible grant application, but feedback and shows stoppers welcome. If a 20% reduction in power consumption on the fridge can be achieved that is a start.

Useful to know,  preferred storage temperatures:

Champagne temperature 10-15C

Chicken 4C more here

Tomatoes 13C

Eggs varies from 4C ?

Wine storage

Lyndsay Williams sensecam@gmail.com

Monday, 2 September 2013

A short history of lifelogging devices

Arduino datalogger 2012

Lifeloggers, people who wear computers in order to capture their entire lives, including physical movements  are not new. My first introduction to lifelogging was  around 1976 when St Mary's Hospital, Manchester  approached me re a design for a device to record the activities of  hyperactive children.  The device would attach to the leg and measure and count the activities of the children. I discussed the use of mercury switches and TTL counters, as there were no low cost microcontrollers or small accelerometers. I was fascinating by this, and was spending a lot of time designing dataloggers, particularly for digital audio.

Here is an example of a similar  lifelogger using a mercury switch and TTL logic to count from this 1978 patent.
The band wrapped around the leg of the child.

Click to Enlarge

1980, I worked at British Aerospace on noise reduction systems for The Queen's Flight.
Here is an example of the accelerometer used to measure vibration of the out of balance propeller, the size of a tin of food.

Moving forward to 1998, I  joined Microsoft Research, Cambridge.  They were interested  technology for a sensing pen I had designed, SmartQuill, but the patent was later bought by Apple for the iPhone.  This was a lifelogging pen, that would record all your written words, and has sensors built in like a camera, tilt sensors to orientate the display and detect the person's physical activity using accelerometers, eyeball tracking,  heat and touch sensors.

SmartQuill handheld computer 1997 - click to enlarge 

In 2000, I designed SmartMoveX. This was a lifelogging device I wore for 23 hours/day (leather is comfortable)  for  months to detect and log body movement using an accelerometer, Galvanic Skin Response, light  and heart rate. I used it while working, sleeping and cycling. It would send me alerts if it detected inactivity and laziness  for more than 30 mins. It was a good way to reduce a person's weight but the novelty of wearing the device wore of after about a year. The device really needed to be smaller.   There is more data  in the PowerPoint  link including some metrics.   You  can buy devices with similar functionality now from Nike etc. 
 SmartMoveX 2000

Time to add a camera

 At about 2000 I  had an inquiry from a friend who was a dentist and wanted a time and motion study recording but also including images of the performance of the surgeon re time sitting down and  standing up and minutes spent on surgery.  I also wanted to help a friend who was always losing his keys. I  needed to design a lifelogging device with a camera  that would photograph every room as he walked through the door frame and so capture a sequence of rooms that had been walked through and so trigger his memory.  I had also lost my memory for many months, when I was at school,  due to a road traffic accident so knew the frustrations of have no recollection of the last few months of my life. (Memory was so bad I could not remembered if I had attended a Rick Wakeman music concert, that had occurred a month before my accident,  normally a concert is etched in the memory) I also wanted a device that could predict what events in people's life would trigger illness like migraines. The SenseCam was like a black box data recorder for the human body, recording motion, temperature, location, images. Heart rate was done externally.

The first sensing camera  I built  was based on a digital Kodak DC20   camera with only approx 16 frames of storage in 1Mbye of memory.

 Kodak DC20 camera 

 I dismantled the DC20 camera and checked  the electronic  shutter circuit. I designed a circuit based on a PIC 8 bit  microcontroller to control  the shutter using a MOSFET transistor  on based on motion  interrupts from an Analog Devices accelerometer. Triggering images using sensing enables much more useful  interesting images than timelapse which can miss 99% of events. Sensing also allowed the use of limited RAM  memory to take more pictures.  I connected it to my bike basket  and got some fairly unexpected pictures in Cambridge, cars pulling up in front of me and startled babies on pushchairs as mothers pushed them into the road in front of me! The images were only captured with a narrow  degree of view, so a lot of pictures of sky or the road. I put the research on hold as no suitable lens.
An early sensecam, no wide angle lens or PIR

 For the Sensecam I  decided I needed a fish eye lens to increase the field of view. After a lot of experimenting with door peep holes lens and similar I eventually sourced a reasonable wide angle lens (130 degrees)  similar to this. A very wide angle lens also has the advantage of a depth of field from around 6 inches to infinity so no focusing needed.

 wide angle lens 130 degrees

 I dismantled the camera, removed the original lens and replaced it. I removed the infra red filter and so could capture IR that the eye could not see. See below for image of King's College, Cambridge  showing the chlorophyll of the green grass but as white. Here is the video.

  By 2004 the rather neat Philips wearable camera was on the market so I used this for tests.
Later Sensecams were based on the camera module from inside this Philips Key wearable camera

I also decided that capturing pictures could be triggered by other life events, e.g. a person moves in front of the lens, so I used a 10mm diameter passive infra red detector to detect the heat from a person.  A Red Green Blue light sensor was also used to trigger images based on light changes, e.g. walking through a door frame. I tried a temperature sensor but after around 20 mins this was warmed up by the body and showed the user's temperature. I did not want to capture audio as an invasion of privacy, hard to compress the listening experience,  and there were also third part devices that did record sound.
I recorded GPS using an external unit as these were  low cost and the data could be synced via a time stamp. I also knew there would be problems in battery life,  getting a very small GPS antenna in the same case as a camera and power supply without electrical interference. There were other problems to be overcome, e.g. the camera module took 150mA to capture a picture which curiously  is  curiously just as high as the current Omnivision camera modules. An 1.5V AA battery with voltage converter allowed 5 hours of battery life.

There are cameras today, e.g. Autographer, (uses the above SenseCam patented Microsoft technology) and Memoto, due to ship soon.

It is possible to build you own lifelogging camera, an Arduino can be used as a controller, with sensor triggers,  and used to control shutter of any camera.  However there are a few small cameras on eBay that are wearable and can be used.

In 2007 I designed and built a life logging lightbulb,  SenseBulb, that tracked the heat from a person and inferred  their activities from heat movements.

Later Sensecams

I have designed more advanced Sensecam's that use heat sensors to detect the heat a few feet in front of the camera , and this can detect the heat from hands moving in front of the camera, people, food, and so trigger an image. I also use infra red system to capture what the eye cannot see. The device is clipped onto the chest like a nurse's watch and can also capture respiration, (GSR) and heartrate.

Audio recording
 There is also a  version that records audio but compresses a day's audio into approximately 5 minutes, so just an impression or montage with no invasion of privacy. It will replay doors closing and opening, trains,cars,  laughter, birds, cocktail conversation etc and so an audio summary of the day. These can be played in synchronisation with the video or as a stand alone impression of the day.
I am testing this at present, Sept,  but some work needed on the speech  algorithms.

Below is an example of a BBC radio play which I am processing today with Audacity to compress and remove the dull parts. (The Archers Sept 2013).

click to enlarge

I am also (2013) working on Sentinel, a  device to predict or avoid early death caused by illness or accident. The user does not even need to have it close to them to capture measurements.  Details under NDA.

Sensecam is a registered Trade Mark owned by Lyndsay Williams.

Lyndsay Williams, sensecam@gmail.com

Tuesday, 27 August 2013

Memoto updates: the world's smallest camera with GPS - and how to design a lifelogging camera

Last update 4th Oct 2013.

The Memoto camera is the world's smallest camera with GPS  and due to ship  November  for $348.75 in the UK.

 4th Oct 2013 Update covering, new investment, new company name, the  hardware design  and a new shipping date from Slashgear. The Memoto company now renamed Narrator.  It is still not clear if the GPS works from this article, but will be shipped without any GPS functionality such as location search. Here is the Sept progress report from Memoto on Kickstarter.


This post covers some of the engineering issues of designing lifelogging cameras.
I was approached by the Memoto team in June 2012 with regards to help with sensing camera design and lifelogging. They were interested as I had designed the SenseCam for Microsoft, (Gordon Bell of Microsoft used this for the MyLifeBits project) and had been working in lifelogging designs since 1997, starting with The SmartQuill, the sensing technology which  is now used in Apple's iPhone as in this patent.  I am also a Consulting Expert for Apple on sensing and phone patents.  I had various chats with the Memoto team but I declined for various reasons including obligations to Northumbia University,  my employer, at the time.
I have no connection with Memoto apart from being an early Kickstarter  backer, but just for a small amount, $35.

Finance and resources

The Kickstater process start in Oct 2012 and it raised $550,000. This was the result of successful marketing including contacting 100 journalists by each of the 15 team members. More finance was planned to be found in Spring 2013 according to the WSJ Blog.
  Memoto has also raised 500,000 Euros  from the London based  Venture Capital company Passion Capital, giving a total of $1.2M. More here on  Secrets of a half-million-dollar Kickstarter campaign.
There have also been additional advance sales of 3000 cameras via the Memoto website, with income of approx $800,000.  Some early software designers staff have left  but there are new joiners  In Sept 2013 there were approximately 22 people working for Memoto.

How to design a lifelogging camera

The Memoto team asked how to design a life logging camera. 
  • Angle of view of lens.
 A wide angle lens greater than 104-120 degrees is much more useful than a narrow 70 degrees of view on a wearable camera with no viewfinder. The human eye has about 180 degrees of view so a sensing camera needs to replicate this.  As the camera can bounce around in different directions as the person moves, a wide angle is helpful as shown in this cycle ride, a  Sensecam video.  We also get about 4 times the image view with such a wide angle lens.  Here is a video comparing a 70 degrees camera to 140 degrees. Another advantage of a wide angle lens is the huge depth of field from about 6" to infinity, so no focusing needed. We get the image from our point of view showing our hands and also the landscape.

very early test image Microsoft Sensecam , approx 2004, view 104 degrees

  • Timing of capturing the image.
 Interesting life moments can be more easily captured using sensing, e.g. sudden movements, you met a friend, or light change as triggered by walking through a door into a new room or vista. If only  timelapse is used in a shotgun approach (e.g. approx every 30 seconds ) then a series of very dull, blurred, and random  pictures can  be recorded and all the great moments missed (e.g. your friend just walks into view but then walks out  - can easily be detected by heat sensor). If the camera used on timelapse  the camera might only be only sampling for about 1% of the time, rather than being driven by interrupts (sensing events).  Sensor triggering of images also allows very low power mode to be used and a whole day's battery life. Reading a sensor such as accelerometer allows a reduction in blurred images by waiting until camera has less movement, e.g. as caused by walking.  When there has been a quiet period for some minutes, only then were  pictures were captured every 30 seconds. The later Sensecams got around 22 hours battery life.
  • use of motion sensing. Using devices like accelerometers allows features like triggering images based on user's motion. It also allow landscape/portrait orientation of image. Knowing the position of the camera allows power down, e.g. place on a table to power down when in a rest room. There are a series of Apple and Microsoft patents, from 1997,  my designs, which cover these features. 
  • GPS design, power and antenna issues
It is not clear from the Memoto progress reports what the performance of the GPS is yet (I  asked on 31 Aug 2013, no reply by 17/9/2013 ) and the hardware and Printed Circuit Boards are still being revised.
There are so many low cost modules that do GPS well, it is easier to pay £29 on eBay for a dedicated unit, example here  but there are better ones. One advantage is the GPS has it's own power supply so not draining the camera battery. It is a challenge to design a GPS antenna in close proximity to other parts of the electronic circuit re noise issues. The human body can attenuate GPS signals.  These reasons are why a separate GPS unit was used with the Microsoft SenseCam. Later sensing cameras and mobile phones can minimise GPS on time by using a patented system, similar here,  that uses accelerometers or light level  to power down the GPS when no movement detected. You can also use the GPS on your phone to tag and find  camera images.
Note that location data is more accurate  in a mobile phone as the weak GPS signal can be assisted with wifi and cell phone tower triangulation. It is possible to get location information indoors in brick built buildings with cell phones. There is also more space in a mobile phone to isolate the GPS antenna from the rest of the circuit. Here is a good article from a Google engineer about battery issues with GPS. Also here is a useful article of GPS antenna design for small tracking devices. With animal tracking devices the antenna length can be extended along the animal's collar. If the [camera] case is long and thin this can help with antenna design.

If I was designing a tiny life logging camera now (2013), I would concentrate on the camera performance, and leave the GPS tracking  to my mobile phone which does a very good job of tracking, e.g. Google location history on Android phones and producing a track on a map.   No point in reinventing the wheel, if someone else has done a good job, e.g. Google. The camera images can be synced to the nearest second via timestamps. The GPS data is shared with Google but at least stored on your own pc and no need to pay to access it. Each circle on the image below have more data and a time stamp. It can tell me how long I sat drinking tea and chatting today!

Click to enlarge - Google location history 

  • Enclosure design. Although the aesthetics of a new electronic design are important, it is essential to design the miniaturised electronic circuit and test with the chosen battery, and antenna so that all fits inside the case. Design the case after the electronics are finalised. Tooling is expensive. 
This is one of the first wearable cameras from Philips: the beautiful  Key19. (around 2004)

  • Cloud storage. If a wearable camera is generating around 4Gbyte/day, which it could if capturing an image every 30 seconds rather than sensor driven, and is required to be uploaded to cloud storage, this could take some time. The fastest broadband UPLOAD speed in the UK today (August 2013)  is around 4.5Mbits/second.  It is preferable to do some image selection on the pc before uploading to the cloud. 
  • Image sorting, classifying  and processing.
 The 2004 Sensecam had an accelerometer, Passive Infra Red, (PIR) microphone (only for level detection), Red Green Blue (RGB) (16 Million steps) colour sensor, temperature sensor and external GPS.  The accelerometer was used for capturing images due to sudden movement and some simple image stabilisation. It also allowed for power down and power saving. The PIR was used to detect and tag people in photos  via the heat from their body.   The colour and light sensor was used to detect step light changes, e.g. walking through a doorway and capturing the vista of a new room. (I had tried acoustic echos to detect a "new room" but light steps were simpler).  The colour sensor was used to determine if using outdoors, indoors, darkness, flesh, pc screens,   in vegetation (green) etc and allowed simple classification of groups of images. Temperature sensing was not optimum as tended to heat up to 37C, i.e. the temperature of the user. These simple analog sensors allowed real time capturing of "flashbulb" moments at very low battery power. The images were all tagged with sensor data.
  The Memoto camera also uses colour to classify images.The images are clustered by their predominant colours and then then a diagram can be produced as to how the colours vary over the day. It seems that cloud processing is needed for this however and at a subscription cost of $108/year + tax,  with VAT this is $129.60 in the UK.

  • Gender issues
Design  the camera for men and women and consider the different clothes they wear. A clip is not ideal for a women's clothing, (remember the trouble they have with  name badges at conferences e.g. with a dress) so consider a pendant? The camera can also be attached through clothing via a rear magnet. Maybe women just feel uncomfortable with a wearable camera,  feel it is intrusive or ask why is it useful? When I was wearing and testing Sensecam, I would use it for sporting events, e.g. cycling but felt uncomfortable and rude in public and so rarely used it.   Out of a sample of 153 early investors for Memoto, only 4 were women, that is approx 3%. Why? It's probably not just Memoto, but also seems to apply to Google Glass etc.

  • Patents 
Interesting  quote from Memoto re patents and intellectual property:

And what about those patents? Källström reckons the idea of a wearable camera is now well-established enough that there are “no patents hindering new applications in that space”.
Hopefully he’s right. What we’re looking at here is a realization of Microsoft’s old SenseCam project, made realistic – if still a bit pricey – for consumers.

   I mentioned  some the above design aspects covered in my Microsoft SenseCam patent, but there is a work around to avoid infringing this patent.
  • Personal Privacy

 It is also crucial to have a flashing light to indicate image captured so people know the camera is "live" and intruding on their  privacy and so will modify their behaviour, as we do, in front of a live camera. There needs to be a method of not recording other people in public restrooms etc which Sensecam had. For privacy reasons also do not include audio recording, there are other devices to do this if people want. 

Hardware Teardown of Memoto

11 months pass (Oct 2012)   from the Kickstarter funds being placed and  customers want to know when the camera ship will ship. I know the challenges of converting a single working  hardware breadboard prototype into a production item, particularly with analogue design, noise issues, power supplies etc,
I am an electronic engineer so the hardware components interest me, a brief teardown as below:

  • Microcontroller Atmel ARM926   clocks up to 400Mhz, A191SAM9G25

  • 8GB FLASH  RAM Toshiba (is this Gbyte or Gbit?)
  • GPS unit, CellGuide's ACLYS Chip,  5mm x 5mm typical power 20mW, indoor and outdoor use, best resolution 3 metres  Here is the spec.
  • GPS antenna external to case 
  • 5M pixels Camera module, one of the Omnivision variants. These modules have auto focus and image stabilisation. The camera uses Backside Illumination for good low light performance.  In the Memoto the camera is used with fixed focus and an optical lens with 70 degrees of view.  As the  Memoto camera is 5 Mpixels it may be based on the OV5640 family.  Here is the Omnivision OV5640 confidential data sheet. 
  • Accelerometer  Analog Devices possibly ADXL346 This has 3 axis , 13 bit output and a range up to 16g. This accelerometer is  used for triggering images by motion detection and also  to orientate images. This technology  has been used in mobile phones, so much prior art. 
  • Compass AK8963 3 Axis Hall effect sensor
  • power regulator 
  • USB to serial  interface, possibly FT232
  • USB connector
  • custom USB charger cable, orange, unsure why custom cable is needed maybe for recharger or CE labelling? (a guess)
  • 4 LED indicators for battery life
  • power on/off there is no switch but possibly controlled by reading accelerometer orientation. 
  • Lithium Poly battery 3.7V 130mAhr
  • temperature sensing, none - only for the battery charging system. It is hard to measure ambient temperature on a body worn camera as after about 20 minutes it warms up  the temperature of the person.
  • other components not identified yet
  • All components fitted inside 36mm x 36mm x 9mm case.

All the above is powered by a tiny rechargable lithium 3.7V 130mAhr battery, similar to those used in model helicopters. This size of battery takes about 20-30 mins to charge.   Memoto claim the battery provides 24 hours of  life. This compares to the OMG Autographer camera (based on Microsoft's SenseCam) that is twice the size but has just 10 hours battery life.
A Li-poly battery similar to this has a maximum number of charges of 500 cycles and cost around $0.85 in quantity.

  Cell phones normally have a battery with around 5 times the capacity.

Image from Memoto showing 130mAHr battery 

Memoto hardware, picture from Memoto Facebook. Click to enlarge

Some of the power reduction is achieved by offloading the GPS calculation of latitude/longitude onto  a more powerful computer rather than the camera. This is actually done on Memoto's subscription cloud service, not the user's PC. Customers comment here re accessibility of their data  being only via the cloud.

Shipping date?

On 22nd  Nov 2012, Memoto  announced  here that "We are now finished with the last tweaks of the electronics and mechanics and are ready to go into trial manufacturing of both". 
There has been much discussion on the Memoto blog of why the ship date has slipped 8 months  from Feb 2013 to now end of Sept (as of 18/9/2013) There seem to have been engineering challenges since Jan 2013 with the performance of the GPS antenna  re sensitivity issues. The case is very small to fit the  antenna in such close proximity to the  rest of the noisy electronics.  The antenna is now wrapped around the inside of the case and tests ongoing.

 Update 30th August 2013, from Memoto,  there is no shipping date yet but there will be  another PCB revision to add improvements to GPS performance. There are 4000 cameras due to be shipped soon, around 2400 pre-ordered via Kickstarter.com.

  • UK price inc VAT

I will wait until  shipping and some hands on review before handing over my money. It will be interesting  to see the camera one day and I look forward to reviews from some customers. I want one for animal tracking, but autumn is here and the animals are starting to hibernate.

Here is a picture found on Google Street Maps (can revolve link  in 3D)  of the site of the  Memoto office.

This is the beautiful  Mjardevi Science Park  with fountains and  Memoto.

click to enlarge

Other GPS designs from Kickstarter

Memoto isn't the only well funded Kickstarter projects to run late with  hardware issues. The Bia sports watch, ($2.75M investment) also with wearable GPS, a tiny form factor and battery constraints. This  has some interesting mechanical but solvable engineering challenges e.g. waterproofing, to solve before shipping. Bia are open with their customers and explain in detail the technical problems and have good customer/investor  support. The image below shows how the Kickstarter funds are being spent.

Other cameras, some  with GPS

Another wearable lifelogging camera with GPS is  the OMG Autographer camera, based on Microsoft's Sensecam, with similar functions but images triggered by recognising  interesting events, but physically 3x  larger, and more expensive at £400, and now ships. I have no connection with Oxford Metrics (OMG).

Here is a  low cost data logging High Definition camera, GPS, wide angle. There seem to be numerous on eBay e.g. like this, £55, 5 Mpixels, 140 degree lens  with accelerometer data logger but I have not tested it out.

Wearable cat camera here.

photograph from Eyenimal 

Claimed to be  world's smallest 5.0 Megapixel camera,  11 UK pnds.

Lyndsay Williams Sensecam@gmail.com