Pragmatic 47: Interrogation Signal

27 November, 2014

CURRENT

We delve into Barcodes and RFID tracing their history and dissecting exactly how they work and where the future of identification technology is headed specifically for shopping experiences.
Transcript available
Welcome to pragmatic in pragmatic as a weekly discussion show concertina practical application of technology exploring real-world trade-offs we look at how great ideas are transformed into products and services can change our lives nothing is as simple as it seems as absurd sponsored by audible please visit audible podcast.com/pragmatic for free audiobook download today is of those also sponsored by mandrel medals a transactional email service that easily ties into your website and apps when you need to send while females like responses password resets acknowledgements and so on visit mandrel.com and sign up today one of its free and is a promo code pragmatic to get 50,000 free email transactions per month for six months normally has a 12,000 of those four times the normal amount integrate deliver track and analyse using email infrastructure from mandrel will talk about them more during the show on your host John GG and they joined once again my co-host because a direct vegetarian I am very very good is a bit cold over there are likely to call radio was much colder last weekend but it's chilly chilly for nearly the go was actually stinking hot over here so there you go. Your I like the cold balalaika heat there we had a rather a record low last week so now we are aware of one annoying heatwave last week to so there are no go figure anyway I'd make some and far and dismissive passing comment about global warming but some year the individual a day by day data points do not equal AER global trend so will dispense that okay is talk quickly about our night dive reviews on iTunes before we get stuck into the episode so the show passed the milestone source this week because pragmatic on iTunes got its 50th written review argument shows about a year old now that's roughly one written review every week which is awesome now critical is that that is very cool and to each and every person that reviewed the show on iTunes many many thanks I over sincerely mean that if you haven't rated or review the show yet and you'd like to say thank you or tell me how I could improve the show please leave a review or a rating on iTunes another idea for using overcast you can recommend your favourite episodes through the app is tap the lie information icon for the episode and then tap recommend so simple attending on cycles when asking for reviews of the shows assuming my last one for a while because I'd I don't like to hear but I like to ask you all the time anyway sometimes I've had feedback that it is wrong to ask for reviews honestly if you want to write one star review you go for it I can't stop you and I would want stopping in tell me what I'm doing wrong that's totally fine because in Aussie fun and ask for feedback then you and anyone of expected exactly me you asked the feedback you're gonna get you if you don't want to feed people's feedback then you know: quote don't tell me but now that's not what I'm saying I want to know and you know some ask feedback and probably get it and you and in my mind that makes it okay to ask because it's a fair and balanced question so so that's all it so it's all good as I'm saying so leave feedback positive negative neutral it's all good I guess the other thing is keep my I look I don't I do the whole donation thank right eye yes we have sponsors but I don't take donations and stuff so if you enjoy listening really that's enough for me seriously really it is a bit as phenomenal as you don't have to but if you do enjoy the show think of raiding it or recommending it as a donation of a few moments of your time and that's all no dollar cost is that an EA can really help the visibility of the show plus it lets me know what I'm doing right or wrong and how I can improve so the ego that's it no more sales pitch were done will lower our miserly data men were done show because were now will get stuck in drops of my beliefs I am not dropping the mike Vic speak that's mainly because of not holding the mic the boom arm is holding the mic and the boom arm seems to be quite robust is not a drop the mic on it own of its own accord and is no quick release either side neither so I'm sorry anyway right we talk about all you must write the topic this particular one is a request that was was the jet was a topic suggestion that is not as voted for this was suggested are in the topics list it was suggested on 26 October so it was only while example approval four weeks ago to 4 weeks ago are Florian hyper and his profanity show from Germany and days and offender chauffeur since I think almost the very beginning so he has suggested this topic and what is the topic guard tonight all about our product identification barcodes that's right but not as a father number shaking nothing but a number here I guess arm but not just that I also talk about the more modern art Westerner which is RFID so I think is a great topic is one that I never considered and I never thought of but it is actually as well as was it really does interest me I find it fascinating and I look at the way things are progressing is worth that it is definitely worth talking about and I find fascinating so here we go indexing and index codes made a point okay gusto it is the point of indexing data is about finding something later as quickly as possible that they could be anything from a book file a record piece of information about any of those sorts of things and indexing allows us to find things when we need them as near as quickly as efficiently as possible and the first one springs to mind I think of indexing system that's in Matthews is the Dewey Decimal system are and that was no sign that Doug I called the Melville Dewey came up with an 1876 and is used in 200,000 libraries in over 130 countries around the world but as an example and indexing system that used to assist you in locating books but you obviously and and that indexing system is built on numbers and indexes can be representing in lots of different ways obviously numerically like the Dewey Decimal system alphabetically symbolically now it depends on who or what is gonna be reading them so for average people we would rather see letters and numbers because that's what we know we know the alphabet or know if certain you did depending on the country that you grow up in if you feel from Asian adult at all Japan or China or yard then they've got some difference different laddering systems but the numbering systems were of bits that is different from from my Western culture but it still boils down to the same thing it's a combination of letters and numbers are you could do a symbols as well but honestly when it comes to technology that's a problem because technology and its entry level and its ability to interpret numbers letters and symbols are it's nowhere near as good as our brains for whatever reason I do sometimes wonder though because about talk about past barcodes with a lot of people talk barcodes from birth if they would be recognised visually but I don't think so so all whole bunch of different reasons it's technologically easier arm for you to read for a computer to read something in a different format that is not an actual number of written number or a letter or a symbol exactly so is far better if it is using uniform squares uniform lines uniform spacings all of that stuff so that uniformity lends itself to while the idea of a barcode and the thing is it a barcode if you think about it previously on episode 39 we talked a little bit about Morse code and factoring up to about previous episode beam before that so no Morse code of course being invented by Samuel Morse and zero it's so did our data targeted at our day-to-day like arrangements AA so It was invented for the Telegraph because union transmitting the formation of a long distances and it was the only way because telephones have an adventure that that point but then I started using it because it was really good for low power transmission and it was used in naval in the Navy for a very long time are so honestly yard think about Morse code what looks like.. . whatever in the spacing between letters if you take those dots and dashes and use was stretched out vertically and you get you create a bunch of lines hey presto you to create a barcode and it is actually true that when they were developing barcodes originally they were inspired by Morse code so kind of interesting or crossover there is a okay so machines of course that I guess the idea is that you want to rather than taking a photo of an object having machine translated something usable you know what I what we do instead is will reflect light or project light off onto a barcode and then will read that data off and then what that does is the the the scanner will then take that information it will convert from a varying signal of reflected light into a bunch of Whitsun spaces and then it will run it through a decoder that says okay well I've got this little width here and that gap there and is the with the I know that's a one okay & so forth rule than through all the numbers to figure out okay well that the numbers like 123442212111 whatever I can so how does that is is very very interesting so go explore some of that so the codes themselves it is numbers right that is the barcode is a sin is essentially a visual representation of numbers in a different format that is easier for a scanner to read that's all this so you'll see at the bottom of a barcode you can see the numbers written those numbers aren't actually read by the scanner bed that is there therefore the humans so that if you try and scan the barcode doesn't work you can then type punch the numbers in manually and analysis our works in you give work to point-of-sale driveway point of sale I'm sure that you had a bucket as work at some point you need is love typing those in the near and then you number wrong is like now no no it's not it's not box it's not it's not steel box it's the plastic box no sorrow over this electronics right we saw boxes so before you get too far ahead of myself gotta start with the basics which is the first kinda barcode was on call this in the beginning but these days it's been retrospectively relabelled as the one-dimensional barcode cause back in the originally was called a barcode anyway so 1949 to blokes guy called Norman woodland and Benard silver folder patent application for classifying apparatus and method and that described to 2 different styles of barcode one was referred to a bull as the bull's-eye the other one is the linear and a bull's-eye one looked oddly like the target logo it was a bull's-eye minnow although I'm pretty sure the target in rip-off versus circular round the circular barcode from her logo but still anyway are the linear style is of course the one that everyone uses and knows and either pack was awarded in 1952 but it wasn't really until the Association of American railroads attempted to use them on their rolling stock for tracking purposes it was in the late 60s early 70s boats are that that people sort of started to take the more seriously but the problem was that CEO in the real world you got dust you've got wind and rain and sleet and blah blah and is inevitably a cause read errors quite predominantly so it was quite unreliable and they actually abandoned the project but around about that time in the early 70s there was a consortium I sure thing as a mid 70s the National Association of food chains and AFC short in the US and what they did was they were looking into barcode as a method of essentially identifying grocery products groceries our products are point of sale that you could then easily linked to a price to accelerate how long how that basically reduce the amount of time it took in order for a cashier to ring up the list on the point of sale terminal of items that you're buying and that was that was the main driving force because I see it is as an attempt to improve efficiency because the old way it used to be done and I'm unfortunately maybe were both old enough to remember this was the was the look up tables yes on item would come in and most somewhat sweet with taxi are the old tag system that had you would dial up that you dial up the little the price the numbers on the on the pricing gun and you have a real of the tape and it had this little narrow maybe half an inch wide our little sticky thing in the little sticky thing you would severe you pull the trigger on the gun and it would though the little hammers would fire with the numbers that you selected and it would be a punch at a price and then you would at this in the same are sort of motion you could then asked of Robert as it were against the surface of the product and that would put a price on it a price on every item you of them is that our year that's right because it was the barcode doesn't contain the price and so that was that was sort of the way it was done so we come to the checkout and what I would have as I have items where individual items were were labelled and priced in that fashion and of course the other ones that won't are they would have look up tables and yet I would look up tables okay what is it so it's this need to be microscopic you this table because grocery stores are huge I have thousands of different things for sale double dipping size the store is posed anyway and I would look through the NSR KM righted surveys are bottle of farm tomato sauce blah blah blah done or catch up to catch up considering the listenership and ego are so bottom line is it was slow and tedious good cashier's would know a lot of them off by heart but know straight away we look all they wouldn't even have to look that you and some of the tags would fall off and have no choice but to look it up in a time-consuming say either consortium said barcodes could help us so they did is they started to develop a standard and the standard is referred to as the UPC which is the universal product code standard and applies to one-dimensional barcode to rely at the time anyway so that's standardised and it was standardised 11 digit code and that identifies any product as a unique product it doesn't identify the product itself as you of I have 10 packets of chewing gum it doesn't actually identify them as this is chewing gum packet number 1006 as is back in 1007 it just identifies all of them as a pack of chewing gum probably in this flavouring of this brand and that's pretty much it so obviously you can build this into the wrapping or you can print it as a sticker and in the early days and even still quite predominantly today it's done as a sticker after the fact but lots of products have built into their actual the actual arm container for whatever it is you're buying so the first want to do it was in 1974 and it was Ridley's with their chewing gum dire mention chewing gum accident like chewing gum but as people today are anyway so chewing gum yes and thus a rigourous chewing gum they were the ones that that first actually had a barcode built into our the packaging but in further analysis of course there were the stickers so you would print off budget stickers stick them on UB to be done if you're good more and more company supported it and made it a lot easier for the people in the shops to okay so that the linear design so are our Norman our woodlands are linear design was was essentially proven to be the winner for reasons that aren't immediately obvious because the thing is that the river bull's-eye one was actually more geometrically tolerant and what I mean you could you could projected a different angle to the scanner and it would scan more reliably from that point of view but the downside of it the big downside of it was that the printing technology of the time and even today tended to streak a little bit because you think you have printer works right so you've got a head overhead is moving the papers moving or both are moving and so at the time and even as they to some extent today as it goes past the woods it would pick up a little bit of residual ink as it went past so when you had the circular ones that the bull's-eye style of barcodes that black would tend to cause a blur and that blur would corrupted the spacing between circles and that would encrypt the data whereas with a linear barcode if you print the barcode on its and that is to say the direction of travel of the paper or the indicators such that are the any stricking does occur is actually along the length of the bars themselves not cross them will not across them and that reading it vertically are yes exactly and therefore that stricking is no longer an issue because your stricking onto yourself them access bit which anyway point is that these ones one primarily for that reason despite the fact that they were a little bit more annoying in order to scan them they actually worked out more reliable in from Internet I get settled look about efficiency and it was the whole point of doing this rather than you ringing up one by one through look up table people's memory and price tagging with price guns so what were the efficiency gains are he will ask well it turns out that there was an improvement in efficiency base and its is not it doesn't sound like much but they did a lot of studies on this in the 70s and early 80s and is about 1 to 2% in a think yourself well the arts is not much but you multiply that by every single day over multiple years and if you're running stores and you have hundreds of stores all around the country even in one state that adds up to a quick cumulative gate yet exactly so 12% improvement they will take it so that however isn't the interesting part the interesting part is that once they did this it improve the efficiency and they had a knock-on effect it actually increased average sales now if you think about it it kinda makes sense if you're standing in line and is taking forever for the people in front of you to get their stuff scan through yellows items your new trolley think NR Nardo learning the yet exactly the second-guessing thing I reckon as were a lot of this comes from because that's what I want a quote I reckon OkCupid shorts as real scientific but the point is that this is immeasurable they measured this tender 12% increase in sales after the introduction of barcode scanned products go figure interesting very interesting okay so that is in a in a nutshell the motivation for doing lobar history about how we got to where we are but of course you know this is pragmatic and I cannot let it pass without discussing exactly how works so you may think it's straightforward maybe straightforward but it's still interesting so there are essentially four broad types of barcode scanner and to one-dimensional barcode scanners the first is called the pen type or the stylus type if you prefer and is the first ones that I saw in use are was actually in a library and they initially were worst sort of common well I say sort of like convenience stores that you would see them you'd see them in our like I saw the menu sector it was at university they were using these but in supermarket chains they tended not to use them because I will bit more labour-intensive and this sort of thing that it did it that he had have a knack to use an aggressor the idea that a spirit savours there is room for operator failure exactly so I car I'm getting ahead of myself that what is this thing so it's essentially it's a pen are it is then usually with a wire at the back more modern ones are wireless and it contains a scanner and a light source built into the tip sort you do is you drag it at a uniform speed and that's the killer uniform speed across the barcode left-to-right right leg doesn't really matter I think action does matter arm it should be left to right across the barcode and if you get it right is tricky to get the hang of it but if you get that uniform speed right then it will pick it up reliably enough but the problem is in a we as year as human beings are really quite quite difficult with uniformity in time so you unlike a machine that will scan a fixed rate every time and with minimal variability the human arm and human hand won't just want so they were prone to errors in reading which would cause frustration because you read it the number would come up there would say you have a packet of razor blades note exactly Packer chewing gum so the reset scan again you have a packet of Oz acting honours at what point is that you are prone to errors avant before I dig myself in a hot laser scanner so a rotating mirror or a set of rotating mirror is move a laser beam at a constant speed and welcomes the conduct of the barcode delight is a set is reflected back and picked up by the sensor now that idea of course means that the laser scanning at a rate that is faster than an average person could move it is one of the things that people you know what when you when you move an item across a laser scanner people think okay you gotta scan like a certain way cycle or do is like a whip in one direction and Selby faster go this direction average and whatever else and I think they get the knack of scanning in a psych of my skin in this way at this rate are at this angle get a faster result or a better result no it's all about the light being reflected back in your heel will be because the beep simply means yes I had a successful scan of the barcode and if you sat the product on the bed on the actual scanner and let the laser do its thing without moving it you'll probably get a better more resign reliable result because the laser is doing the work moving your moving it is confusing the laser so you and if you watch the arm that the checkout operators you they get very good at simply sliding across the power because they know that it'll pick it up as it goes across the panel summer ones GI problems with the BNI sometimes I have the PCR barcode printer dancing with a curve on it or if it's a slightly elective or if there's a bit of dust or dirt or greed or something like that and those sometimes I condensation I called yes get a good one yes condensation is a problem and you have to hold the different angles together just so that the laser will scan it correctly are and that's you it's not only with the movement it's got to do with the other laser's car striking at an angle where it picks up all the whole entire length of the barcode in one in one scan without distortion they distortion anyway okay so the idea is shameless as so the idea is that Saddam vowed that idea sorry has been the most preferred way of doing it pretty much the last 25 years so laser scanners good okay CCD is now there are essentially two types but the original type and still sought popular is the single row there very densely packed together light sensors they read ambient light reflected off the barcode and that's the key difference but it's also a single strip so the idea is it's linear in the same sense of the barcode is linear and that's more cost-effective than the fourth type which is in imaging type which is account what what most will call a camera sensor now is a two-dimensional array of CCD elements that Matthew was ever called digital camera and it literally takes a photo of the of the barcode and runs its image processing software to decode it and that is becoming the prevalent method and it's only becoming prevalent because our the decoding is becoming are better faster cheaper all the same sort of reasons lower power all of those things and all is also becoming more common because it's more flexible will talk about why in a minute there society points the panel laser are essentially they share a common problem will feature right they eliminate the barcode using a specific wavelength of light that is emitted by the laser so that means that their photodetectors are specifically selected for that wavelength the EMS archive is fine it's good it's bad maybe whatever but we note that notice that is still something to be aware of in as a limitation the technology but honestly it's the sensor that is interesting so how it sensors the light is an excellent link in the show notes for photosensitive devices it's by RA Marston and Tony Van Rune it's really really good if you really will read about how those particular photo sensors photodiodes actually work and are I encourage your reader if you're right if you're interested but before we dive into to much of the technical detail like talk about our first sponsor and that's audible audible as a leading provider of premium spoken audio information and entertainment that allows listeners to choose audio versions of their favourite books while you want to do this while many of our day-to-day activities you need your eyes on the job so it is a book you really want to read it so busy with other things you just can't find the time or that audiobooks come in it's much easier to multitask when you're listening to music podcast or an audiobook with your driving doing housework yardwork with audible you can still read your favourite book and not miss out it's really cool you buy books individually or it can sign up for the audible listener program which gives you book credits each month for a low monthly fee you can download your audiobook to your PC or your Mackie Windows phone Andrew Apple iOS device listen to it where ever you might be I'm a huge Douglas Adams found name will know this arm love his stuff and is when I had a local audible had there's about 20 different audiobooks in their library and includes all of the hitchhiker's guide to the Galaxy books the dough gently books are as well as the other two Doctor Who episodes he was involved with including shader which was the unfinished episode that never got aired and it's in Taiwan they have finished filming at the anyway are anyway it was the base of the first study gently booked urgently solicitor Detective agency are with Dr Prof can notice and all the minor Reebok economy about art or better still get the audiobook and listen to the best part though about some of his books is that they read by different people so some of them 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want to talk about most common ones are the LDR which is stands for one light dependent resistor that's the original our technology that was commonly used for the scanners and sometimes they called a photo conductive cell or photoresist it depends on the speed to the construction of an LDR you have two terminals they connect to each end of a strip of photo conductive material and is placed on supporting insulating substrate usually ceramic of some kind and it weaves its way from one end to the other usually in a little snake pattern like a zigzag of sorts now different photo conductive materials respond differently to different wavelengths of light cadmium sulphide was the most commonly used because it responds like wavelengths are within the human visible spectrum and because was relatively cheap but I said was past tense because now cadmium is considered heavy metal and heavy metals the enemy and therefore it's been restricted in many many countries now so it sort of fallen out of favour that's okay other technologies of come along so it's all good but anyhow the way that works is that I guess some certain materials when light young photons hit them some of that charge will free up electrons and that reduces the resistance of the material itself to innovate the bright light intensity arm as the bright light intensity increases the resistance decreases so in dark environments the resistance is higher so these LDR's can drive a transistor amplifier or an amplifier or operational amplifier a.k.a. an op amp are and these can in turn then drive relays and eventually they can be useful for turning on and off things like streetlamps that say the AI Montana nighttime and an application the other signals are very small and using each subsequent application stage to drive more and more power obviously is not the context and amusing inverses that do not appoint that LDR is used for that purpose can be right photodiodes his little-known fact all silicon PM junctions I photosensitive who knew while I guess I was to someone for that out to someone new AI photodiode is a conventional silicon PM junction diode in a case both your transparent cover that allows light to reach the junction so real quick about silicon you have an doped MP don't silicon one has holes one has in excess of of electrons are essentially based on the different doping is used now when when light hits them then some of the charge creates holes that can carry more electrons which then means that it reduces the resistance of the silicon at the junction itself I say creates holes what I mean to say is that it is essentially the charge transfer pushes those holes to become vacant to allow flow is the best way of putting it at least AI it comes down to the fact that the energy that is imparted based on you that the light wavelengths the photons that the energy imparted has to be enough to overcome the bandgap for the electrons so that they can jump to the next energy level and you can actually get current flowing and once that's achieved it works like a charm now phototransistor is the same kind of thing is photodiode same thing but is a transistor so PMP NPN and same thing it's transparent cover but the additional junction and the geometry there of a transistor house physically put together that different geometry makes them far more sensitive to light and photodiode okay so CCD's and imaging I am going to cop out right there and say I'm sober for future episodes stay tuned if you care deserve the upper cult itself is a topic all to itself will get to its it is on the list well it is whether it is on the list or on the official list or on the unofficial list I don't know but it's on the list believe me so now we can get back just briefly to our to touch on that's roughly how the scanner the component works so essentially are all the light in the dark you parolees things together and like essentially can then you can use the ER the deaf individual detectors Detective the light or dark and that the text whether the light is reflected off of the barcode hey presto you can then digitally recreates the structure of the barcode as a as a representation of binary ones and zeros in the scanner which you can then convert into the actual numbers a breast liaison scanner a few more notes about laser scanners are they are awesome because they work over longer distances go up to a foot usually quite easily are but the downside is they won't usually work with a smart phone image because swell was there trying to reflect light off of arm you know an opaque sticker so those are some of the older scanners will not work all that well the new CCD ones will work with anything pretty much because of their essentially taking a digital image that I worked just fine with a smart phone image you provide enough ambient light or go the Yum the backlight on your smart phone is turned up high enough because you know there's apps and that will allow you to scan intake photograph of your cards whatever might be and you can then you scan should display that and then as you swipe that over a CCD scanner it will recognise the barcode and away go so and that's awesome but doesn't work with all the scanner so it's a little bit of a flawed in between tech and that leads us to the next generation the next evolution mention of all we add 2D because like when when the 3D yet that's okay maybe someday will do that very moment 2D is where it's at and everyone knows the most common well-known popular two-dimensional barcode is called Vic the QR code yes it is and the ostensible I do not stands for the quick response code which is a really dumb name but never mind that whatever that's was dance for let's just run with work we accept reality and and all its imperfections because while we don't have many choices so there's lots of different ways of doing it but that has turned out to be the most popular one was originally put together by a Toyota spin-off called then so are denser Corporation thing originally called then so wave are back in 94 are so those Toyota spun off and you didn't do in different parts of their vehicle manufacturer and component tracking and stuff like that are was was designed for this was the component tracking should say either semi or fully automated vehicle assembly systems made use of the QR codes announce instantly recognisable by its square of dots are many the dots will touch each other on one or more sides but it's the three squares of which you have a solid square in the centre and a square border around it missed three of them 123 usually on the top left top right and bottom left sides although of course you can argue that depends on how you will look at the code it sounds three of the four corners of the square and you'll know that they know that that is specifically as a QR code now the reason that you have those those are or equidistance they are fixed our spacing and what they do is that they allow it to allow the imager to compensate for three-dimensional skewing of the image because when you take an image the image you cannot tell whether or not the top like the top left corner is closer to the CCD than the bottom right corner and that causes the skewing of the data and of course corrupts the data somewhat by having squares of an identical size and identical spacing are in the X and Y directions you can compensate for any severe any visual skewing when it scanned the school you yet I thought about photos come the bow working away all right so the amount of data that you can store in a QR code symbol depends a lot on a bunch of different variables so there is are the mode the input character set and of course the version the version refers to the size so are versions I think vary between 140 R 40 being the biggest one being the smallest and that affects the overall dimensions of the symbol so are you is so for example 40 will be taken several is can can be several inches wide but obviously still had a lot more information we able to make sense anyway and is also error correction built into as well and you can have differing levels of error correction based on the reliability required from the data when you scan the Wikipedia article is not too bad because it gives you some examples there is also another link in the show notes are to either QR code website itself that talks about the standards in depth the most common QR code that I've seen in use is the version 3 so you may ask so it stores more data or how much more data compared to UPC so you take as an example one the most common which is version 3 that's a 29 x 29 grid title owl numeric games important to specify all that upfront is all that affects how much data can store hundred and 27 and this is all based on numerical digits not to an alphanumeric sum to amount numeric digits because UPC is numeric digits so we go compare apples to apples here so again most common barcode you are to one a metal barcode is a UPC type a so hundred 27 it was for the QR code and how many for a traditional barcode the answer is only 12 that's significantly more year it's huge by comparison the log about the numbering system are on a UPC A-Z of the professional is curious are the number reaches the very first time you get on a one-dimensional barcode is actually are refers the numbering system so far zero is a regular 07 are both regular UPC codes are to is weighted items in their market the store so the awaited item then are you put two in front of barcode identifies what it is what saves oranges in any whatever else the barcode organ identified as is an item that needs to be weighed for example and then calculated based on our three list yet yet you they they fade put a lot of thought into this arm three in front is the national are drug or health-related code just to differentiate those sorts of grocery items from the others are a number four is an in-store use after non-food items and their birth of the following code structure adult about a minute are is not required size, a free-form flag that you can structure that the remaining 11 digits however you choose well remain 10 digits the last digit being attracted to become you are and are a five is for coupons the other numbers the other preceding numbers are simply reserved for purposes that are that I am not aware of so following the first digit you have five digits manufacturer code 5 digits the product code and finally a check digit which as Clinton point out the chat room is a checksum of sorts mouth will have its that's the structure of the BCA coat now QR code structures are very very different because of course the data can be used to represent a whole bunch of things because gossamer more options most common use of a QR code that people come across is a URL so you can use it alphanumeric leader describe a unified arm uniform reference locator which you like tech distortion.com but you buy a bit of course yelling short is of course been a smart way to go you would usually short so the UPC code will describe the link shortened URL to save on alphanumeric are size and then I would take you to a promotional website and hey presto the ego prickle okay so now we want talk about is the next evolution of identification in the next evolution of of that is RFID's best the best the trendy stuff before you do talk about those however unlike some of our second spots of this episode and that's mental mandrel is a scalable reliable and secure email infrastructure service trusted by more than 300,000 customers worldwide that's a lot I been asked what is mandrel because most people understand email newsletter showing other inbox and a lot of them come from MailChimp which is also an excellent service was mandrel or manual essentially is the foundation that MailChimp is built on and it's been broken out its own service for discrete email transactions rather than one big mailing list like MailChimp so you can think of them like individual transactions and hence the terminology transactional email and that she has started in the two years leading up to 2012 mandrel borrowed a bunch of MailChimp's best engineers and work in isolation little skunkworks project became mandrel and is now the largest email is a service platform on the market with more than 300,000 active customers like us before of which I am one now let's say you're a website like tech distortion for example any dissent feedback form confirmation emails or mandrel can do that sit tech distortion is systemic as it CMS and I run the raven forms as a plug-in and when you do is at the API key for mandrel and asset just works straightaway straightaway no other tweaking required as a bunch of new features on our on the site lately and they all like topic suggestions inside and they all used our mandrel for all the emails I had been using standard PHP before that are there female boats is a switch to mental it's been much easier to 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communication is technically what RFID is utilised however when not talking about pay past pay wave Apple pay Google wallet NFC-based technologies and the problem with the terminology that I have as its vast dilation is a conflation of terminology so NFC refers to the method of communication from a near by physically nearby radio interrogation to a response and look at it from that point of view whereas RFID is a specific technology that is built using NFC principles so RFID uses NFC to transfer the identification information that they're looking for in the what is the technology and the other is the application of our yes the other is an application that utilises the technology enemy and I saved the technology like NFC is a technology will NFC is not a technology really what NFC simply refers to is the fact that you have are with radio signals there is what I refer to as the near field which is only a handful of wavelengths away from the source of origin of the raw RF energy so near field simply remember means that it works in close proximity to the transmitter and only works in close proximity to the transmitter because when you are in close proximity transmitter that you can get our an effective power transfer and make sense limit anyway okay so RFID types let's go through the work before permutations and combinations as some of them have really funny abbreviations let's start with Pratt is right Pratt passive reader active tag cause are the next one is an active reader passive tag active reader active tag passive reader passive takes will get go through each one is not so passive reader active tag Pratt this system has a passive reader and it only receives the radio signals from the active tax so in other words your tags got a battery unit is active and you reader well it just sits there and when lessons active reader with a passive tag this is the by far the most common animal will focus on the most in this episode and that is that system has an active reader that transmits an interrogation signal and it receives the authenticated reply from a passive device how that works will make sense in a minute ago active reader active tag obviously that is a combination of the above two and passive reader passive tag will as a failed technology since it doesn't actually do anything because it's far just its passive-aggressive Lego think it through okay PS sorry I do is it is the is the fourth combination right got a mental note don't because it doesn't exist okay biggest advantages of active tags is that they allow for higher frequencies and look for and longer distances sound like a bonus and it can be but the disadvantage should be obvious that in a power source even if you put a long life low drain lithium battery and these things again have a limited lifespan and honestly this is a mass produced they don't want to mass-produce them with a replaceable battery so typically they don't so they use and further to 3 years battery dies Chuck Mack another one the status the way that they attend work so anyway are and it also makes the more expensive now the way passive tag works is really kinder I think is kind of ingenious sorted that what they do is you're not passive RFID tag because it's about 1 in maybe an inch and 1/2 square obviously get larger and smaller ones with the amount of exercise and you'll see a series of concentric are conductive strips and are all on on the sticker and sticks inside a product some thieves only referred as security tag right technically there is an RFID tag or rather it's the same kind of technology that you can put RFID into it to those those conductors that than a little pattern that they form what they do is they essentially act like a coil now are with with with a liquid electrical or magnetic system when you've got a rotating alternating magnetic field electric field then it will induce a current in that conductor which is exactly how generator works generator spins around it it induces a current in the windings generating electricity so same kind of idea so the idea is that radio energy is an electromagnetic wave severely trimming wave is carrying actual energy you can capture that through these RFID taste through the through the concentric are conductors that form the antenna and that energy charges are very very small current very very small model not much doesn't need to be much it charges a very small capacitor that capacitor will store that energy so what happens it sends outburst that is sorry the interrogator that the reader the active reader it will send outburst of our electromagnetic radiation irradiation referred to as a radio the radio signals awesomely say hello well okay doesn't say the word hello and I mean that I be really creepy if it did anyhow so this I digress so the yell RFID tags what's happening in new RFID tags you there is getting more disturbing by the second point is our yes that the RFID tags then that the charge in the capacitor then drives the circuits and it's a very small very low power transmitter in the RFID in the centre of the RFID sticker and that will then respond so it then transmits its response and its response is of course its own identifications will respond with a radio signal and modulated essentially with its data which is its own identification code who goes there yet exactly any response with its name who it is what it so the interrogation signal's arm is on for a brief period and then the response signal is on for even more it is wrong for slightly longer. But it's very low power response and because it's because the device is only able to be powered by whatever charge it accumulated from the radio signal from the active reader from the interrogation signal okay so far so good okay cool obviously RFID is used in a whole bunch of different applications now the one we're talking about specifically is identification of goods at the point of sale baskets there's lots more was Malcolm specifically talk about but are still in sting and worth mentioning is tracking of goods in a warehouse and access management that is to say access control and I have RFID tags on my security that my security badge by going to my building at my place of employment in my job I swipe the card and it has an RFID in it and it responds with you it's John's letter men or no evidence to evince the kitchen area don't let this guy and he looks treasonous deal all the rest of the year the mince and write access management to the abstract are tracking of persons or or animals so you sometimes they'll put RFID chips in a very small injectable tube that can be injected underneath the skin and you can literally track like you and they chip a dog and they do all cattle whatever that is an RFID tag and that is injected under the skin and is no that allows you to be tracked which is kind of raises all sorts of other interesting issues we will when I can go into this episode but never mind that our toll collection are so you driving a car you got a transponder in your car you drive through the address yet I saw the speed pass are here here in Brisbane is referred to as the modest Brisbane that are indifferent because Australia got the toll are E pasts and arm go via there's a whole bunch of different names of different consortiums and are all subtly different but they're all the same technology essentially no contactless payments like your Visa card or your MasterCard or more you your new shiny new iPhone six or 6K Apple paneer Apple watch the doesn't have released yet or because of an android phone for years in them so while not all of them but some of them so contactless payments are travel documents no airport baggage tracking so that there's so many places where RFID is used but we only really interested in point of sale for the purposes of this discussion I think it's best to focus on one component okay so the major advantages are unlike a bar code you could scan multiple RFID tags at the same time backs the timesaver is aware that all is a big win the other major advantage RFID's can be completely covered as an physically covered and they don't have to be visible to the scanner and you can still scan that's a big advantage to more data to ISI sure that's true yes that is no advantage Kara major disadvantages in 2011 the average cost of a mass produced passive tag was nine cents US each now if I do custom UPC labels because I couldn't get the anaconda couldn't find an equivalent mass produced cost but if you do limited production runs of a thousand or more UPC labels these are standard UPC one-dimensional barcodes you look at three cents each US now that is you obviously one third of the price now obviously is also printed many times it's printed onto the product at the time of manufacture but there are certain there are some stores where they want to override that their own reasons or you this budget reasons why men wanted irrespective the point is that is significantly cheaper rate doesn't sound like a lot of money but honestly if you not getting my relative gate accumulates it's a lot and if you're not getting much of an efficiency gain from the expense than why you doing are the disadvantages anyway are the get more maximal elevators a minute that the other disadvantages are that is more fragile than a barcode so if you get it wet can kill static discharge will kill them nearby lightning strikes and power surges can kill them because they're designed to accept and amplify a radio wave and capture all of that energy was really good at capturing static discharge and of course the EN pulse from a lightning strike as well and ML have such a high voltage because it is uncontrolled that it can fry the RFID chip below the So you know the good none of those issues affect barcodes or gay so all that's all well and good I hear you say Barts let's talk about the whole idea of the whole multiple things once where could we get to was the real big benefit from using RFID is in a grocery scenario well before we get into that think about the cost problem which is the passive tag that I quoted the whole nine cents each those are the cheapest passive tag that you can get that they only have a small sensing range nevermore the new technology the new technology will that's yet I can scan multiple metres CO 10 feet away let's say but the cheap ones I just mentioned the ones are packed potentially borderline cost-effective they have a very short sensing range they increase the size of the tag to improve that but obviously that increases the size the antenna increases the cost and before United service all over red Rover EY you do it's just not worth it anymore so and the problem is simple right as I discussed previously in both episode 16 and 39 you're up against the inverse square law RF travels in any an ever expanding bubble in that sphere are the the energy X decreases rapidly as that expands into the distance away from the source of the RF energy from the from the actual active reader so you know that it should be obvious now you have to go to a bigger one to get further away again I refer you back to the advantages of the active readers with the actual battery power source in them because you can go further away because you need a project as much energy and immediately projecting an infinite amount of energy because you projecting in amount of energy you fry the poor person stand next to less true yellows those PayPal as he told things don't stand in front of them for eight hours a day like the eight at the side of the motorway don't do that bad idea anyway aura 16 and next to a mobile phone tower at like 10 feet away is also done that it either okay so as costs come down ultimately where you want to go with this technology is his the concept locate you put everything you want in a shopping trolley you walk through the exit RFID scanners read everything on a trolley it automatically charges your pay wave pay pass Apple pay payment method of choice wirelessly and you just keep on walking out the door down done and dusted that's the pipedream well that's the dream when it is to be a pipedream it remains to be seen but we know and is not a reality yet but it's getting closer so as a slight tangent just briefly Wellington Calgary is over a decade ago now Calgary car was trialling a scan as you shop experiment done at the still doing it but I know that Tesco is doing and the idea is that as you put an item in shopping trolley you scan it with a portable battery powered scanner and as you guys Asia 90 scan it when the choice In the trolley it keeps a tally of how many of each quantity see scan each wind got 10 individually wrapped biscuits well sorry cookies whatever our EU would scan all 10 of them so keeps tally of exactly what is in the trolley and it's all linked into their pricing system and can give you a running tally is fantastic however the downside is it's all about trust and honesty were all trustworthy and honestly honest are we Vic Collier everybody on my totally hundred percent honest anyhow accept that statement so so you know that what the weather got around this at the at the co-op was that they would do a random check so you would you would log in the system you would swipe your card and it would say yes how your your John CG and yes we you've been here three times before and it kept tally of how many times you use the system autonomously and happy times you had not had use a system without art without having essentially a law a shopping trolley check at the end sought they would do as they would flagging the first couple times to see if there are discrepancies so they would even a scan is when the trolley they will direct you over to another I'll now say you will do this manually put you through anyway and I would do Italian you're just you would build up a history of trust and it was also based on the holidays so if you only had $50 worth on your tally list and I had a look in the trolley and I see I looked about $50 worth based on a cursory glance then you they would tend not to check you however obviously there's ways of gaming that system you can hide are the you could hide more expensive items inside and amongst the larger cheaper items to make it appear as though you're good you know you are so I'm sorry if they do pick you out I forgot to scan those LED light bulbs or hiding in the cereal box for some reason anyhow you know is that the easiest you can gain the system brain you so is not ideal but RFID is would use exactly the same idea but it removes that trust issue because you can scan the whole trolley and determine what's in it agoraphobia labelled to the cereal where you find them lightbulbs so this is the problem is that while that is why the game and assess them to you could remove the RFID tag from packaging beige up with a Faraday cage while that's actually interesting because it's one of the points if you have a metal trolley that's going to feel the RFID signals because it is a Faraday cage released on 5/6 sides unless your shopping trolley ML shopping trolley also has a lid which I haven't come across one yet but maybe there is one I don't think so so the plastic trolleys which I have seen in some stores and they still remain relatively common enough they would be the choice if you're using RFID should go with plastic trolleys you you've used plastic tries before I take it our you the metal is more common are yes you're right metal is far more common because far more robust you are talking about what we call it "your rates are yes sorry shopping cart shopping trolley at same thing different name shopping cart indeed okay but of course all that presupposes that the RFID signals you're reading are exhaustive and correct and up until now I have been daddy recently got up to around about the 99% accuracy and you realise if you a bunch of RFID tags in physically proximate to each other like literally only millimetres apart that causes issues is very low alloys issues yet interference issues so there's all sorts of ways that they they have to do handling the CAS possible read them all at once began sort of that is in own kinda what you want to do is you avoid multiple people talking over the top of the syllabus and multiple people on people the RFID is a people belittle people that I feel people that will RFID is the point is all talking over each other same time and that's a bad thing because you can't separate them out and then it was talking once the local who said what who're you what you are 90 more cedars give up and it leads to an approach we would stagger so you would say okay on the scan all of these fellas only people that start with these numbers respond these numbers response on your cycle through any group based approach another reduce the statistical probability of having 100 responses at once now has multiple ways of overcoming that depending upon the radio technology that they use in an so-and-so for the novel to get into all the details but there's ways of overcoming it arm but they are more expensive are they are becoming cheaper it's certainly not impossible and it is improving all the time and as analogous as the message as RFID technology improves further it becomes more sensitive it becomes cheaper and more reliable as to say there are less missed items in the trolley that I can actually see this happening in fact I'd wager this probably store someone will already trialling this and if there is and is probably five or 10 years away from becoming are commonly trialed or even a common thing for certain supermarket chains because think about you free up checkout attendance it's worth it's worth the investment employees cost money and cost a lot of money especially when I get sick ego had a get sick I just you honestly from from from a former employer point of view forget that people have any rights whatsoever to live a life right employees dark right that they're not productive all the time they stand around and they talk to other employees they get sick that they taught that that they arm they make mistakes you know they cost you money some of them are in no dishonest in and take money out of the tills in a minute all sorts of issues of employees so if you have RFID's all one of those promises disappear you don't need the checkout attendance are in order scan the items anymore is push the trolley through you need to move some of the attendance back in the chain in the store seeming to have someone mending the deli and the fresh food area are yellow all the bakery or we however part of the story if your shop does have those areas of course some don't but you know because then I would have to do put in a bag programmer label put the label on the bag and so the ghosts are no so so the RFID would count but that could save grocery shops a supermarket a lot in wages and that alone makes it worth exploring and honestly that's all I had did you have anything else you want and severe to the discussion at all Vic garlic Lego so thank you again very much to our Florian for that suggestion I think is very visit very sick of you have answered that good topic getters good topic and are and I would strongly encourage our listeners that want to contribute to the show and have things they want me me to talk about our plea suggested topics and is are if I agree I think it's a good topical put out there and people vital and will pick from the list and that's how this one was added to the list so thank you again if you want talk more about this you can reach me on Twitter and John Geagea and that you can see my writing and this podcast and others I've made a host that my site tech distortion.com like to get in touch with the Vic how can they are reach you Vic they could phone me on Twitter advocates in one either of there will be a new episode of absolute podcast tomorrow for Thanksgiving here in the UK and the United States are also restricted a fantastic cool can't wait you may have already getting back on Lisbon umpires for a while a is a surprise to the guests no assets are same on warfarin's epitaph tag should be of some interest to some people are so little wasn't wary know about if you want to find ways to do tag on and meditated the shells and share pieces of and stuff like that is an app that does that fantastic excellent while our lobby link in the show notes to that absence of such an app yet so if you'd like to send any feedback please use the feedback form on the website that's where you also find the show noticeably absent on the pod casts pragmatic and as for the topic of this episode if you would like me to cover any topic at all can suggest it and then other people vote on site under topics once you sign up for a free account of the site are also started to release exits in the show that are off topic and a couple of the main episode I'm calling addenda look for on site under pod casts addenda also find pragmatic show on Twitter decision announcements and other related stuff I like to say a final thank you to our two sponsors for this episode are there and they are audible please make sure you visit this URL audible podcast.com/pragmatic free audiobook today and also thank you to mandrel sponsoring show if you're looking to improve your site and the section email reliable integrates easily and provides easy tracking and analysis and mental can help visit metal.com on site today use the promo code pragmatic to get 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People

Vic Hudson

Vic Hudson

Vic is the host of the App Story Podcast and is the developer behind Money Pilot for iOS.

John Chidgey

John Chidgey

John is an Electrical, Instrumentation and Control Systems Engineer, programmer, podcaster and runs TechDistortion and the Engineered Network. John has produced and appeared on many podcasts as well as Pragmatic.

What Happened to Mastodon? You can reach me on the Fediverse as explained here, just search for me on your instance of Mastodon, Misskey or Pleroma and you’ll be able to follow/remote follow me wherever you are!