Tuesday, 14 October 2014

Apple Watch Digital Touch

Apple have shown the new watch to the media. This has a Taptic Engine or "Digital Touch". It allows a person's  heartbeat to be transmitted as an actual bump to another person.

Image from Apple.

 I designed and built similar technology for Microsoft, more  here in 2005. This used an optical sensor in a mouse to measure heartbeat and transmit to another user as a haptic bump in their hand.  There is no patent and all in public domain.

image from 2006, mockup but working hardware tested

Recently I have been evaluating this technology for mobile phones. All the hardware exists in mobile phones, e.g. camera and vibrator.

Sunday, 25 May 2014

SenseGrip - Tablet computer with real control knobs

This concept design allows physical controls to be added to any Android 7" tablet pc. This allows easy grip silicone rotary knobs to be used for frequently used features such as volume, scrolling, video position, camera settings,  radio tuning controls etc.
Many of us prefer real physical controls, e.g. photographers, musicians, assisted living applications.  A current 7" tablet pc is like handing a slippery sheet of glass.

 Each rotary control is a digital potentiometer with 1024 bits of resolution, tactile feedback  and is also a push switch.   Physical push switches are also provided, these can be used for power on/off. High power speakers are also included. The device can be used in portrait or landscape mode, the tablet's accelerometer automatically sets this and also the stereo speaker orientation (tablet's speakers or device).   Additional sensors such as local and  remote temperature sensors can be added. The device is clipped onto the tablet computer, automatically detected  and communicates via Bluetooth Low Energy. A USB charger socket  is provided  for the internal battery. Size 200mm x 30mm x 8mm. Powered by ARM microcontroller with Bluetooth. The controls illuminate in the dark.  A silicone grip allows easier hand control for the tablet computer. A tilting hinge is also included. In portrait mode the device can be held in either left or right  hand. Sensors in the hand grip allow for medical sensors in future designs. Tactical feedback can also be provided.
CAD image of device next to 7" Tablet

The device is also designed  for photographers. 4 physical rotary controls can be assigned:

  • aperture
  • shutter speed
  • zoom
  • manual focus 

a push switch for the shutter
Tilting holder provides trip facilities  for time lapse, webcam  or life logging photos
flash for camera as omitted on some tablets.

There is a device that provides camera buttons for the iPhone but it has dedicated controls for a camera function only, e.g. the Red Pop. There is also an accessory for the iPad to provide easy grip but no controls.

The new device can be created with a 3D printer including the integral control knobs. Their position is detected using a  low cost robust non carbon potentiometer.

This design can be built as a working 3D printed prototype.
Design by Lyndsay Williams, Cambridge
+44 (0) 7970 101578

Monday, 24 February 2014

Wearable Computers - A cure for Sleep Paralysis?

This is a paralysis that occurs on waking from sleep, usually in the early morning in some people.
Here is an introduction to sleep paralysis,  report  from the NHS.   The mind works, the person can control breathing and possibly also foot movement, but the rest of the body is paralysed. The sensation may only last a few minutes but is terrifying, Drugs can be used to cure it but a non invasive method may be preferred.  Sleep paralysis  also seems to run in families and I suffer from it at least once a week. Every time I have it I am determined to find a fix or cure for it, but on waking and the morning arriving,  the fear has gone.
 I now  have time for revisiting  sleep paralysis. I also had previous not put much effort into it as I thought of interest to only a few people but  it may occur in up to 8% of the population.
The proposed  sensor device is attached to  the foot close to the toes under a band aid  (the person can wriggle toes in sleep paralysis).   A bio sensor detects motion and wakes up the person fully by a piezo  alarm. The sensor will be washable and reusable and should cost around £20.  The software algorithms require the right degree of sensing so every time some one moves in bed they are not woken up, only when in sleep paralysis.  Breathing is easier to detect but quite invasive to go to sleep every night with a chest  monitor (I did this once for 4 weeks but not again).

There has been prior work on using sensors for detecting sleep paralysis but the devices were quite cumbersome for wearing every night.  I also build a  proof of concept for  an Early Onset Epilepsy detection system for the p3i  Lab of Northumbria University in 2011.
Here are some earlier notes I did on sleep paralysis in 2012. I proposed an ankle chain but in the last two years we now have a smaller  ARM computer 3mm x 3mm x 1m with built in accelerometer, and tiny Lithium Polymer batteries so can fit under a band aid.

ST Microcontroller 

Most of the research work will be in the software for optimising the real time filtering algorithms and user trials.  The hardware proof of concept can be tested with the Texas SensorTag.

Contact Lyndsay Williams sensecam@gmail.com or +44 (0) 7970 101578.

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