This project involves designing and building a 'Colour Reader' for the blind or visually impaired. The device will contain an embedded system capable of measuring a range of colours on surfaces of differing textures. The Colour Reader will relay the colour recorded back to the user either through a speaker, headphone, Braille reader or a combination of the above. Usability, size, weight, accuracy and battery life are all issues to be considered in the design of this device. Embedded system design, C programming, sensing, voice synthesis and interfacing will all be used in the solution to this problem.
So it’s the first week of third year and I am about to start my project. In June we got a list of all the projects being offered and I chose “The Colour Reader”. My aim is to design and build a device which, when pointed at a surface, will sense the colour of it and read it aloud to the user. I chose this project because I wanted to use my engineering skills to help others and this will allow many blind or visually impaired people to have much more independence. It could be used to help blind people choose their clothes and shoes or another example would be if a colour blind person wanted to be an electrical engineer – it would be very dangerous mixing up different coloured wires in this profession!
I started off by looking at other colour readers which are currently available and I started to get nervous! They look very high-tech (see the photograph of the Brytech Color Teller below) and I didn’t know what I could do to make mine better. After I met my supervisor, however, we came up with a possible method of differentiating my colour reader from those already available. We thought about how the colour reader was going to work and decided that a sensor would have to sense the light level from the surface which we wanted to know the colour of. However, if the light in the room changed, it might read a different colour. Therefore we came up with the idea of making the reader in the shape of a torch which would remove all the ambient lighting and provide its own light in the form of an LED.
I decided it might be a good idea to contact some prospective users of my product so this week I have been in touch with the RNIB in Liverpool about possibly surveying and interviewing some of their members.
I am getting quite excited about my project now as I feel I may have a product which could potentially be manufactured on a large scale and sold. I am still worried though as I now have an idea of what I want the finished product to be but I just don’t know how I’m going to get there! In the coming week I am going to try and draw up a block diagram of the whole system which may help me get a better idea of where to start!
This week I have been doing a lot of planning. I have drawn up a Gantt chart which basically shows all the tasks for the project, the main deadlines and a timeline. This will help me to keep track of my progress and I have shown a section of it in the image below. Along with this, each week I write a progress report and send it to my supervisor the day before the meeting. In this report I just write what I have done in the previous week, what I plan to do over the coming week and then a list of questions I need to ask him. The meeting each week lasts for one hour and this report ensures the meeting has direction and also reminds me of all the things I need to ask him!
The RNIB in Liverpool didn’t email me back which I was a bit disappointed about however I found a phone number on their website and got through to one of their staff members. She gave me her email address so I am going to try this and hopefully I will be able to get in touch with some potential users of my product. I figure that it makes sense to consult with visually impaired people the whole way through my project as they will know better than me what functions the device should have. They will also allow me to compare my device with others on the market.
I have asked the disability support officer for the school to contact all the visually impaired students and staff at the university on my behalf to see if any of them would be willing to help me, either through filling out a questionnaire or by meeting me for an interview.
Everything is going quite well still. I have begun to draw up a questionnaire to send to as many potential users of my product as possible and have also begun to look at components which I need to order such as LEDs and sensors.
This week it’s time to get to work! I’ve had the time to get my head around most of the project and so I can begin to think about design. I need to find some method of measuring the height and angle at which the LEDs and sensors will be placed. In the school of EEE we are lucky enough to have a mechanical workshop where we can go and explain our ideas to the staff. Then they build you something which does over and above what you expected. For example, I went to speak to one of the members of staff and explained the following:
"I need a rig on which to mount a sensor and an LED. I need to be able to change the height of them and the angle at which they point to the surface. Also I need to ensure that no light from the LED is sensed horizontally by the sensor, the light must only be reflected from the surface to ensure the colour is as accurate as possible."
I came back a few days later and they had built me this:
As you can see I can move the LED and sensor through any angle which can be accurately read from the protractor, and I can also change the height.
We have to hand in a progress report for the project at the end of week 8 so this week I have begun to think about how I am going to lay the report out. I used the mark scheme provided in the third year project hand book and researched progress reports online for real projects to help me draw up a contents page. By doing this first I was able to get an overall feel of how the report should look and it also helped me to stick to the 10 page limit.
One of the requirements of the progress report is a full risk assessment of the project. This just involves identifying all the dangers in the labs and workshops and deciding how these can be avoided. One example of particular relevance to me is the risk of repetitive strain injury (RSI). I have problems with my back and elbow so it is very important that I sit correctly and take regular breaks when working with computers.
This week I have been in touch with the RNIB shop in Belfast. They have sent me lots of information on colour readers and what they felt was good and bad about them which has helped me to add to the specification of the reader.
I have designed the circuits to test my LEDs and sensors this week. This involved some simple calculations using the information from the data sheet and I then drew the circuits out on some design software. I could then begin to solder the components onto some Veroboard which is just a board with long strips of copper on it and lots of holes for the components to slot in to. You can see the circuit in progress in the picture below along with the circuit design.
Although the progress report is not due until the end of week 8, I am going to send it to my tutor on the Friday of week 7. This works out well for both of us because it means he has 2 days to look over it and also my sister is coming over from Ireland to visit so I doubt I’ll be getting much work done.
I have mainly been working on the report because the deadline is fast approaching! This has involved bringing together all the information I have gathered from reading scientific papers from the IEEE website, books in the library and surveying potential users into one concise report.
I also wanted to include some measurements in the report but putting the circuit together has taken a lot longer than I thought it would. Therefore I have had to submit the report to my supervisor without these measurements. I plan to try and make the measurements in week 8 and hopefully get them added on to the report in time. Fingers crossed!
My supervisor had sent me back the first draft of my progress report with some suggestions as to how I can improve it at the start of the week so I went through it and made as many changes as possible.
As I mentioned in the previous week’s blog it took me longer than I thought to build the circuits so I have begun to test them this week. On Thursday, however, disaster struck! I accidentally shorted out one of the resistors of my circuit and blew the LED. As the LEDs I am using are RGB LEDs they have to be ordered in specially so I have been unable to include the light measurements in my report. I am a little disappointed, but I think the rest of my report reads well and there is a lot of content in it so I’ll just have to keep my fingers crossed until I get the results of it in 2 weeks time.
This week has been a bit of a bad one. I have had labs for my other subjects and reports due in and on top of all that my Dad was in hospital so my mind wasn’t exactly on the project. I just went to see my supervisor and we decided that the best thing would be for me to take a week off the project this week and start again next week.
Everything is much better this week. My Dad is out of hospital and I have all my lab reports handed in for this semester. All I have to do now is work on my project and start some revision for the January exams. This week in the meeting with my supervisor we discussed what my next moves should be.
The next deliverable is a technical poster but it’s not due until February. Bearing in mind that I have exams between now and then, however, means I have to have it in the back of my mind while still carrying on with the practical work. So between now and Christmas I am going to get my circuit working again and get some measurements done of the reflected light level when red, green and blue is shone onto pieces of different coloured card.
I am also going to look around the corridors of the Electrical and Electronic Engineering building and see what aspects of the posters done by the students of previous years that I like and dislike.
This week has been an interesting one! I got to interview Dr. Robert Stevens who is a senior lecturer in Bioinformatics in the school of Computer Science at the university. Dr. Stevens has done a lot of work in assistive technology for disabled people and so he was able to guide me in my work.
Coupled with this, he is blind himself so hearing his opinion on the features my colour reader should have was invaluable. He made the important point, though, that he is only one person and I need to speak to as wide a range of people as possible to make the reader as useful to as wide a market as possible. Amazingly, he was able to offer me a route in to this. The school of Computer Science has links with a charity called Henshaws who give expert care, advice and training to anyone affected by sight loss or learning difficulties. Some students from the university volunteer for Henshaws and he thought if I was able to give up a few afternoons a month I would be able to talk to so many people with sight difficulties and make my product as relevant as possible. Obviously I jumped at the chance so I am currently waiting on more information but I hope to start volunteering next semester.
Work has continued on soldering up the circuits on Veroboard for the LEDs and sensors. This has been quite slow moving which is frustrating. Things keep going wrong like I’ll solder something in upside down or I’ll make a break in the board where there shouldn’t be one which is difficult to undo. I also really want to get a lot of measurements taken before Christmas so I can draw up some graphs over the holidays so the pressure is on!
I’ve started to think about my electronic poster which is the next deliverable for the project. It needs to be eye catching, explain all about the project and also show how much progress I have made – not a lot then(!). I have started this week by making a list of the headings I will have on my poster such as Background, Software Development, Hardware design etc. Then I looked at posters from previous years for more ideas. I have also begun using Google Sketchup to design the hardware as I think this will look really good on the poster as it is unlikely the reader will be in its final form by then. I have included some pictures of these initial designs.
On the whole though everything is going well. I am still really interested in and enjoying the project and am just trying to do as much as possible in these last two weeks so I can spend the four weeks holidays revising for the January exams.
Now exams are all over, it’s time to begin work on the next deliverable for the project. We have two weeks to design a technical poster showcasing all the work we have done so far on our project. The poster must be for a technical audience but not necessarily for someone from my subject area. This will be tricky!
I started by writing down possible headings for the sections of my poster. Introduction seemed like an obvious one, then a hardware and software design section, a section to show experimental results and a conclusion. Writing the text turned out to be one of the easiest bits! One of the highest areas in the mark scheme for the poster is the ‘visual impact’ section. Now I have always been into maths and science but art was never a strong point! I spent the three years of compulsory art in secondary school splashing paint on a page and pretending it was ‘abstract’! I don’t think the same excuse will work this time!
I really wanted to include a graph on my poster which would display the first stages of how the colour reader will work. To recap, the stage I am at now is I’ve got the RGB LED circuits built so that the red, green and blue light can be shone individually and the LDR is hooked up to a digital multimeter (DMM) so I can see the difference in resistance various light levels provide.
First of all I had to work out the angles at which the LED and LDR should be positioned at to ensure the maximum amount of light would be reflected from the surface. For this I had to spend ages in the workshop looking slightly strange with a coat over my head so that the ambient light of the room wouldn’t affect my readings. I took a shot in the dark with the red LED on which might make it clearer. From this picture, although it is difficult to make out I had to blu tack a bit of black card inbetween the LED and the LDR. This is because I was worried that some light may be leaking horizontally across to the LDR rather than being reflected from the surface. I found the best angle for the two components to be placed was 55 degrees for maximum reflection.
Having found the angles work could begin on mapping the resistance values read by the LDR when red, green and blue light was shone on card of various colours. I then plotted these values on a mathematical program called MATLab.
This allowed me to plot a 3 dimensional scatter graph with the points being coloured according to the piece of card which yielded the values. This will be built up for as many colours as possible over the coming weeks allowing me to predict what colour the surface is on the basis of the resistance read by the LDR when red, green and blue light is shone on it.
I thought I had completed my poster in plenty of time for the noon deadline on Friday however I ended up sitting up until a ridiculous hour on Thursday night making more final touches! I hope you think the final product was worth it! Needless to say Friday was spent sleeping followed by a few celebratory drinks -after lectures of course!
With the poster out of the way I have begun to look forward on the project. The next deliverables aren’t until near the end of the semester so now is the time to get some practical project work done. I am still very aware of the time constraints on getting this project finished and am getting a bit frustrated with having to try and de-solder components every time I make a small mistake. Also waiting for components such as the voice chip coming in from the supplier will take a while.
I explained all these worries to my supervisor who suggested using a data acquisition tool manufactured by National Instruments called a myDAQ. This will allow me to make a working prototype of the colour reader in no time at all. It plugs into the computer via a USB port and works as a power supply, DMM and also has functions such as storing wav files which will be the sound files I use to record the voice announcing the colours. The circuitry is attached to it with a prototype board (see below).
I am really looking forward to using the prototype as it will be a real milestone in the project. Then all I have to do is find a way of fitting a PCB, 3 components and 2 batteries into a 13cm torch – easy peasy(!)
The work with the myDAQ begins! As you can see from the picture, the myDAQ plugs directly into my laptop via its USB port. This means that I can work on my project almost anywhere. I began by going on the National Instruments website which has loads of really useful tutorials on how to use the myDAQ and Labview.
Here you can see the Instruments Launcher included in the software for the myDAQ. The main functions I will be using will be the Digital Output (DigOut) which will allow me to turn on the red, green and blue LEDs sequentially. The digital multimeter (DMM) will then read in the resistance values for the LDR when the various coloured lights are shone on different coloured surfaces. This will make it much quicker for me to build up an entire web of colours and allow the predictions to begin!
I began by just using the myDAQ itself to turn the LEDs on and off to see if I could get the colours to turn on and off sequentially.
Having familiarised myself with the myDAQ kit and the associated software, I am now ready to adapt my circuit to allow my to control the output of the LED from my laptop.
Eventually I will be able to write some software to do this automatically when a switch is pressed. I have run into some problems with my circuit this week. To use the digital outputs to switch the LED on and off I need to put in some transistors to act as switches. Some revision of second year circuit theory is required!
Another problem has struck! The LED package that I have has a common cathode for the three individual colours. This means that I have to swap the whole circuit round and use a PNP transistor instead of an NPN. Back to the second year notes!
I was still having problems with my switching circuit yesterday as the digital output of the myDAQ only provides 3.3 volts, not the 5 volts that I thought it was. I now have to go back to the drawing board to work out all the resistor calculations.
The final circuit is shown below.
The red wires provide the 5volt supply voltage to the different parts of the circuit and the black wires are ground. The yellow wires are from the digital outputs, each of which will control a different LED. The grey wires will connect to either terminal of the LDR and then feed into the analogue input of the myDAQ, allowing the light level to be read.
Having worked out the angles at which the LED and LDRs should be placed at a while ago, the staff in the mechanical workshop were able to build me a prototype torch head in which the components could be mounted to ensure they were held in the same position at all times. This is shown below.
The red, green and blue wires coming out of the left hand side correspond the red, green and blue LEDs. The red and black wires protruding from the top and right hand side connect to the two terminals of the two LDRs.
I also have a deadline coming up now as I am heading back to Ireland on the 18th March. When I am home I am meeting my friend who is blind. She has a colour reader but says that there is so much wrong with it in that it is rather large and cumbersome to use and it also can’t tell what colour it is if the surface is stripy.
I want to have a full working prototype by the time I head home so that I can let her try it out and comment on whether it is better or worse than the one she has. The pressure is really on and with each new challenge I have to take one step back to go two steps forward. Coupled with this, I am now thinking about the final report. This is worth 50% of the module and is due in in six weeks time so I need to start making a plan for it. Oh well, nothing else for it but to keep ploughing on and hope everything falls into place soon!
In these two weeks I have had an assignment due in for another module which counts for 50%! Therefore my project has taken a back seat. Luckily enough, my supervisor understood and so I just concentrated on that and I’ll get back to the project when I have handed it in.
This week I have been glad to get back into project work again, having been writing an essay for weeks! I have decided that if I want to minimise the size of the colour reader the best way may be to use three separate LEDs instead of one RGB LED. The reason for this is that separate colour LEDs come in much smaller packages.
Due to the cylindrical shape of the torch, no space is really wasted by doing this. The guys in the mechanical workshop have started work on this this week. I have been continuing to use LabView to write the software to allow my colour reader to work as this software allows sound files to play.
Hopefully when this is working I will be ready to give my viva voce, which is kind of like a presentation which must be done in week 23. I also have an executive summary to write before Easter so I need to start work on it as well. At Easter, I plan to go back home to Ireland for a while.
I had to make the decision about whether to stay and do work in Manchester or to take my project home with my and work on it there. I have decided to stay in Manchester for the first few days of the vacation and get my project well and truly finished, then I can head home for the holidays with nothing to worry about (apart from all the revision that is!).
Well it’s the week before Easter and the 10th week of the semester. This week I had to write the executive summary for my project which is a one page document summarizing my aims and objectives and how I met them.
It was not easy to get a whole year’s work into one page but I think I just about managed it. This executive summary does not receive a formal mark but rather it is marked as part of the viva voce. When I am doing my presentation the markers will have this document in front of them so they can see if I have completed the work as I stated I did in the executive summary.
The Easter holidays have begun though it doesn’t feel like much of a holiday for me! The first three days were spent in the lab trying to get the project finished. Unfortunately the smaller torch head with the three separate LEDs was not finished by the time I had to go back to Ireland so I just had to settle for the prototype torch head.
At this stage my project is running behind and I am starting to worry that it’s not going to be finished in time but thanks to the National Instruments myDAQ ‘lab in a bag’ I can take the whole thing home to Ireland and work on it there but also spend some time with my family and friends. If it were not for this piece of kit I would have to stay in Manchester which would be very disappointing for myself and my family as I have not seen them in a long time.
Over the Easter holidays I got my project finished so it was reading 13 colours however the wires were still being held in with Blu-tac! Obviously this would not look very impressive in my presentation so I went to the mechanical workshop to get it glued.
Unfortunately, because I had to pull the Blu-tac out it was impossible to get the components at the exact same angle, therefore the colour reader stopped working. As the glue was permanent I couldn’t change the hardware so I tried to adapt the software so the colour reader would still work for the 13 colours. It would only work about 10% of the time but at this point I realised I couldn’t spend any more time on it as I had to put together the slides for my presentation.
I was extremely nervous presenting my project as it technically didn’t work so I was worried I wouldn’t get any marks. I just put all the work I had done and the reasons for it not working into slides and hoped for the best. The presentation was difficult as the first 15minutes was me presenting the work I had done and the second 15minutes involved me being asked questions by both my supervisor and a second marker who was a member of academic staff who I had never met before. I was most nervous about the questions but I quickly realised I had no need to be as when you have worked on a project for almost 9 months, no one knows it better than you so you can answer any question they throw at you. The marking system is also designed in such a way that it doesn’t matter if your project doesn’t work at all, or works perfectly, you are marked on you technical achievement so it is completely fair. I ended up achieving 72% in my viva – I was over the moon!
With the presentation over it was time to start work on the project report. This counts for 70% overall and I definitely should have started working on it before now! The report involves writing up everything you have done including research, hardware and software design, testing and future developments.
There are also a lot of marks for project management which involves how well you planned your work and how much assistance you needed from your supervisor. After a week of very little sleep, endless queues for printers and binders and horrible sandwiches from the library it was done.
Having submitted the project report I was extremely proud. It was a long hard struggle and there were lots of stress and tears but it was all worth it in the end. If I could pass on a piece of advice on the project to anyone it would be start early and finish early and most of all enjoy it! It is the only individual project you will do throughout your degree and it really gives you an opportunity to work on something you are interested in and show off your ability.
With the report submitted it is time to start studying for exams. I seem to say this every week but why didn’t I start before now?! I have only one week until my first exam and need to revise 12 weeks work! I have to admit though after writing the project report, I am kind of looking forward to studying!
Well all the exams are over and as I write this I am sitting in University eagerly awaiting my results. As I am an MEng student this year will count for 50% of my degree as will next year. This summer I am working in the University as an Intern in the school. My job involves designing an online quiz for 14-16 year olds which will hopefully encourage them to get into engineering. I am enjoying it so far as it has really reminded me why I got into engineering and why I love it so much. With the money I am getting paid I am also able to see around the sites of Manchester as my evenings and weekends are now completely free – it is a very strange feeling!
I hope you have enjoyed reading my blog. I have been totally honest through the bad times and the good and overall I have to say all the stress was worth it. These three years have been an extremely enjoyable challenge and I am looking forward to my fourth year project already.