BuildBrighton

March 26, 2011 Previous day Next day
talkingjazz

Phonics Owl

Posted by talkingjazz Mar 26, 2011

Following on from Thursdays meet-up, as often happens I started looking at toys. The Early Learning Centre has a selection of phonics (keyword, not necessarily  actually phonics) related educational items, including a few electronic ones. Goodie.

 

I was upset and distressed to find that the Peppa Pig's Fun Phonics was not in stock. They did however have an exciting looking Phonics owl which appeared to contain quite a few similarities to what we were talking about on the Thursday meet-up. It also had a little toy owl on it!

The box had pictures of the cards that came with it which appeared to be all time same shape, size and colour with no visible contacts. Score.... something with contact-less ID's. Lets see how other people approached this commercially.

 

So anyway.... here's the Phonics owl thing:

 

001 - Box.png

It was also avialable with a little bear.... but owl's are way cooler. Here's the back of the box:

002 - Box Back.jpg

So this thing has 2 modes, and comes with 17 pairs of cards. Not sure yet if the pairs are the same, or unique (is the Apple card the same as the A card - or are they unique?)

 

On with the action, lets get it out and start playing:

 

003 - Set.jpg

 

First thing I noticed is the cards are actually card (sounds a little silly I know). They all have light blue backs and are indeed all the same shape. Putting some screws on the back , they do not stick. So if there are any magnets in there, they are very week. The base of the recess for the cards in the base unit is also made of card, ooo, probably a reason for that not being made out of plastic. More than likely a plastic base would have been too thick for doing whatever is going on here.

 

Les have a play:

 

004 - Assembled.jpg

Quite nice. When you pop in the cards the base reads out either the letter "The Letter A", or the word "Apple". When you put in a matching pair you get a nice little jingle and a "Correct". When it misreads a card (which happens if you only half insert the card it tells you to remove the card, insert a card or something else. The message it gives seems a little random between cards. No doubt related to the mechanism behind the card reading.

 

I was also happy to see there is no problem with putting the cards in the other way round (Apple in the first slot, A in the second).

 

So, there is a minimum of 34 unique cards (17 * 2, as it knows the difference between letters and words). So at lease 6 bit assuming there is some kind of digital reading going on. It could still be analogue, but that seems unlikely.

 

Here's a little video of it in action:

 

 

Nice, the unit seems to work pretty well. The cards a a little tricky to get out though. Again, possibly related to the reading system.

 

So then... how is it reading these cards. Before opening it up I decided to have a bit more of a play with it. Look what happens when you put on more than one card at once on the same space...

 

This video has been deleted from the system.

 

Interesting.... if you put more than one card on the unit at once, it reads something that's not either of the cards. And you can place the correct answer in the second slot and it tells you it's the correct answer. Further to this, it doesn't work with all cards. Some cards will read off just one of the cards you put down. Using more than one card, you can place one of the cards in the wrong way round and still get a valid read (something you cannot do normally).

 

So, now I'm figuring we are looking at some kind of capacitive reading system. As there are 34 possible cards (6 bit) and the system knows if a card is the wrong way round... a system that can be fooled SOMETIMES, by having one the correct way, and one the incorrect way... We must surely be looking at 7 bit, EITHER where the 7th bit is used for orientation checking, OR the capacitive sensors are positioned so that they do not line up when in the wrong way. I'm putting my money on the first option, as the system will give the different reads with cards the wrong way in.

 

Just before I started to open up the thing, I accidentally knocked some stuff off a shelf and on to the reader. What a spot of luck, it started saying stuff. So we have discovered you can cause reads to happen by placing something metallic on the reader in certain positions. See below.

 

008 - Blade on Reader.jpg

By moving the knife blade around I was able to generate a few dufferent cards (both letters and words). Before opening up the device I decided to open up a card and see what makes it tick.

 

009 - Open Card.jpg

 

Just as expected, there some conductive material in the cards. This card no longer works as some of the black conductor got ripped off and there is no longer any connection in parts. Where there is a connection the material seems to have a resistance of 2k/mm. Don't have a conductive pen so can't play with making my own cards quite yet. But this does confirm some of the operation of the cards and readers. And why it works when you stack cards on top of each other.

 

Anyway... lets get this thing open.

 

010 - Opened Up Top Side.jpg

 

First thing to note is the large number of inductors on the top side of the board. There are 8 of the larger through hole ones, 8 transistors, 8 diodes, and 8 pairs of wires going to the board attached to the reading area. There are also a couple of 22u caps and 4 more inductors on this side. They don't appear to be connected directly to the sensor part of the device.

 

The mode is also set through the power switch. The mode of operation is configured through the green and orange wires marked P23 & J1-2 on the PCB.

 

Also notable in the above picture is the leads going to the sensor board on the left. They are short, but covered in sleeving and heatshrink. May well be that these leads are shielded to prevent interference.

 

Lets crack on...

 

011 - Opened Up Bottom Side.jpg

 

Looking at the bottom of the board we can see the speaker. Following the traces we can see that some of those extra inductors are used as part of the audio output system. Other than a couple of passives, the speaker is connected to the larger chip marked U3.

 

The smaller blob on the back which is unmarked has traces leading from the power input, and has the other inductors connected to it. Some kind of switch-mode supply one would assume (the device runs on 3x AA's).

 

There are also 2 LM324 Quad op-amp's in the surface mount packages. There are some connections to the 8 leads going from the sensor board to these chips. So these must be used to amplify the output from the sensor board.

 

012 - Opened Up Sensor Board.jpg

 

And there we go. Each redder has 8 pads on it. Looking at the card we took apart earlier, and testing a few more connections using foil, the centre is common and connected (via the cards) to each of the outer pads. Each of the outer pads is connected between the two readers.

 

One interesting thing here is lower middle left and right pads. These are the only 2 that are not symmetrical. Instead the 2 inner pads are connected. Perhaps it is this that stops cards being inserted in the wrong way round (via means of a calculate-able checksum perhaps). The card we took apart earlier does have a connection to one of these pads. If you replicate the other connection on this card on the left hand reader (where the other pad would not be used), it works file. However when you do the same on the right hand reader it will not work. Interesting....

 

What's next?

 

What ELC have done here is very interesting. It appears to be very reliable. Cards are very easy and cheap to create. There is not too much hardware involved in reading the input cards. And it's all kept well away from the user.

 

Might have a play with getting something like this up and running.

4490926175_b414163f7e_b.jpg

Mitch teaching people to solder at BuildBrighton, photo by Barney

A Letter From Mitch

Sunday evening we received word from  Mitch Altman that we, along with 30 other hackerspaces, had been  accepted into the Great Global Hackerspace Challenge. If you don't know  what it's all about, check out the hackerspace challenge group. On hearing about our acceptance into the challenge we decided to meet  up as soon as possible to discuss ideas for the our project. A few of us  met Monday lunchtime in a pub called The Hampton and started throwing  ideas around.

We started out trying to understand the requirements:

  • Your hackerspace will create a project to help with education, using  US$900 (or equivalent) provided by Element14
  • Must use a  microcontroller
  • Must use a portable power source
  • You have 6 weeks to complete your project

Edumacational

Firstly  we discussed what constitutes education, it could be anything from  drooling pre-school toddlers to spotty, disinterested teenagers or even  post-graduates. Education doesn't even stop when you pass your twenties,  there's plenty of higher-education institutions and courses being run  all the time.

I personally shied away from suggesting we aim our  project at children anywhere below 16, as there are lots of safety  concerns to take into account and environmental factors to consider when  designing your hardware. For example, if you're using hi-strength  neodymium magnets you want to be damn sure they're not going to fall out  of your invention and get swallowed by kids. They can snap together  inside a person and cause all sorts of unspeakable mischief. Less  dangerous, but still important, is the fact that any contacts, switches  or wires you have will get covered in grubby, sticky... whatever it is  kids are covered in. And does anyone know what the resistance of that  substance is? Nope, me neither.

However on the plus side, there's a  lot to teach kids. They've not been around for long, and their brains  are like information sponges waiting to absorb knowledge. Also, between  our members we have contacts in schools and education, and we've already  run a succesful project helping kids visualise data they collected by  attaching arduinos to their shoes (it was called Data Steps).

Jason,  one of our newest members, suggested some sort of device to help kids  learn Phonics. For those who have no idea what Phonics is, which  included me a few days ago, it's a way of teaching English to kids by  letting them learn the sounds that particular letters and groups of  letters make. There's a much better explanation on Wikipedia,  as usual. After much googling and discussion, we decided that this  sounded pretty cool and started thinking of ways to teach it to kids in  the 5-8 year-old range. The ideas ranged from a speak-and-spell like  device to something more akin to traditional Alphabet Blocks. These ideas started to converge, and our current plan is to make a device whereby the kid has a 'target' word shown to them as a picture, e.g.  'Cat'. They have to find the right phonics and put them in the right  order to make the device say 'Cat'.

Why Phonics?

Phonics is used in many schools across the UK and America to teach children how to speak and spell English. It's also used the world over to teach English as a second language. Phonics has been widely debated in the US congress and is generally accepted as an effective way to teach early reading skills. As recently as November 2010, the UK government has announced plans to train all primary school teachers in the use of phonics.

Anecdotally, lots of people we've spoken to have said that tools for teaching phonics are a bit basic, usually consisting of flash-cards or DVDs. There are some electronics based toys on the market, but most of them just use fixed buttons as an input. We think that using a more tactile input method would engage younger children better and aid their learning.

Layercake

Our plan of allowing kids to choose phonics and have them spoken by our device allows us to split the design up into several layers:

  • Input - the phonics chosen by the kids and the target word they are going to spell out.
  • Control - the logic that controls the input and output, detecting what phonics have been placed down and giving the kids feedback.
  • Output - speech synthesis, a sampled audio player or some other indication of whether your phonics are correct.

This means that we can prototype the input and output methods separately, and split up in order to try out different ideas in parallel.

 

Ben very helpfully put together a brainstorm of various input methods we've been discussing along with their pros and cons (click the images for larger versions):

Input method.png

... and a block diagram explaining the layered architecture and possible implementations at each level of the device:

GHC-PhonicOverview.png

Thursday Meetup

At BuildBrighton, Thursday evenings are our social meetup night and we decided to use it for our first proper planning session. To kick off, we went over the requirements of the project again just in case anyone at the space wasn't up to speed yet. We went on to discuss how to split up tasks and agree to report back the same time the next week. Here's how the tasks were distributed:

  • Toby  
    • Manage the project, making sure we meet our deadlines and targets.
    • Input: Investigate RFID, and multiplexing RFID antennae
  • Ben  
    • Input: Physical input devices, e.g. punch cards, switches etc
  • Chris and Ben  
    • Input: Look at re-purposing their cube-input project for the challenge
  • Mike  
    • Output: Android text to speech API
    • Output: Android device screen as an output
  • Barney  
    • Input: Colour sensing
    • Input: barcodes
    • Input: UV binary dots
  • Jason  
    • Output: Speakjet voice synthesis chip
    • Output: Waveshield or similar for sample-based speech output
  • Matt  
    • Input: Reverse engineering existing similar toys (he likes taking things apart)

    • Output: Implementing voice synthesis on commodity (cheap) microcontrollers

 

Other members have offered hardware, advice and time to help out everyone who's been given specific tasks, many thanks to everyone who's getting involved, it's looking like this is going to be a great project!

The prototyping starts

Later that night...

 

Toby starts making RFID antennae and trying to wire them up through a multiplexer. The antenna works, but for some reason it's not getting through the multiplexer:

 

Jason sets up his Speakjet chip and gets it talking to his laptop over serial:

 


Next time...

By the next blog post, we should be able to report back on all our prototyped input and output devices. We'll post pros and cons for each and narrow the field down to two input devices and two output devices. The chosen input and output methods will be refined further and we'll decide on which ones to actually use.

 

In the mean time, we'll also be researching how phonics is used in schools currently and how the control system needs to work in order to most effectively teach kids how to talk.