My name is Arthur Guy and this is my personal website.
I am an electronics engineer, a web programmer and an amateur photographer. On this site you can find my blog (below) and details about me and what I do as well as examples of my work.
Trip List, the site for managing trip signups
A few years ago when I was organising trips for the University mountaineering club and wanted a better way to collect peoples names for climbing weekends I decided to build the trip list application for Facebook. It took 2 days but I came up with a very usable application for setting up a trip and allowing people to sign up. After I finished my stint as social secretary for the club I forgot about the application and just left it to fend for itself.
I have recently decided to pursue a career as a freelance web developer so I decided to go back to the application to refresh my Facebook programming skills; I have spent a few hours over the past week improving the application and fixing a few issues that arrose as a result of changes to the Facebook platform over the years. I have now finished and have an application that works well again.
Its been fun working on Facebook again, it really is an easy platform to develop for. There are a number of quirks to get used to and things you can’t do and Facebook’s recent changes regarding messaging are an interesting change. They now don’t want applications contacting users through the site itself, they either need to email the user directly or they can place a number (think unread count) next to the application name in the sidebar. Both of these methods don’t seem ideal but I can see why they are making this change, in there eyes these changes are further separating the application and its identity from Facebook preventing annoying spammy apps from affecting the brand.
Earlier in the week I went to London to apply for a UK Identity Card. I have wanted one for over a year but it was only at the beginning of the month that they opened them up to the whole population rather than a few test groups.
Home Office - Identity & Passport Service
There is a lot of debate surrounding privacy especially the identity cards, large groups are opposed to the idea of a national database containing contact and biometric details.
I am certainly not one of them, I can’t see the problem to a national database and I am amazed there isn’t one already, the UK has a lot of lists or databases across various departments each of which contains a selection of the UK population but none of them contain a complete list. The National Identity Register will unfortunately add to this with another database but hopefully if it takes off and the Conservatives don’t get into power and scrap it it may eventually replace other databases and provide a single unified database.
If the National Identity Register does go ahead I would like to see some web based management and viewing for users. A lot of the worry is caused by the uncertainty people will have about who is viewing their information, there is an easy way to solve this. Every search or request for information by a government agency or business should be logged, this information should then be available for users to view. If you could log into a secure site and view all the information the government has on you as well as every company that has ever requested your information it would put people at ease.
I should get my card in a few weeks but I seriously doubt any kind of system for seeing what information is held on me is available or will be available for some time.
How much would you spend on a sign or a series of signs covering a university campus? A couple of thousand? How about £700,000?
Land fenced off for new signage
A week or so ago small sections of land started getting fenced off around Sussex University campus where I study and work, attached to the fences were signs saying trenches were being dug for new signage. In relation to the few signs and maps scattered around campus at the moment a lot of new ones were going up so it seemed a little excessive, today I found a brief article explaining that a campus signage review had been carried out and new signs were being installed at a cost of £700,000.
This is a figure I think a lot of people would find over the top, especially for signs but it really depends on what the final result is.
If they are just going to be as simple as maps on a stick then I think it will be a waste of money but something like this is a fantastic opportunity for the university to do something great. Rather than just maps these could be interactive information points, computer terminals displaying the latest university information or serving location information and people finders. I am certain they won’t be anything like this but they could at least make them semi decent by using them to extend the poor wireless internet service available on campus. These information points are everywhere and it looks like most of them would have power for lighting so it would have been a great opportunity to add wireless repeaters to improve coverage.
The other issue with this is the cost, I imagine a large portion of the money would have been spent on the external audit of the current signage, why did this need to be external? A few years ago the university paid a company £2 million to come up with a new brand including colours, logos and a general look, this is a specialised thing requiring lots of skilled people and I believe the money was well spent, this current project doesn’t require a high skill level just a moderate level of competence which I hope anyone working at the university would have.
Anyone could have analyzed the current signage and come up with a new plan why did they have to waste money on an external audit especially at a time when the university is in financial trouble and needs to save a lot of money.
Hopefully they will start to go up soon and I can see what they are going to be like.
After posting that a personal tracking device wasn’t feasible because of power consumptions issues it got me thinking, is it?
I haven’t worked this out yet so as I write this I genuinely don’t know if it is possible to construct one but I plan to work it out, considering both size, power and practicality.
I have seen devices on the market which do this type of thing but none do exactly what I want, my specifications are as follows
The other requirement for this system is that I can build it, that means no (BGA) ball grid array devices but I can deal with pin pitches down to 0.1″.
The system will be composed of 4 main parts, GPS, communications module, processor and battery. I will look at the GPS first.
GPS devices require a lot of power, they average around 30-40 mA at 3.3V which is a lot of power for something that needs to run all day, there are also different types of antenna, the common ceramic one needs to be pointed up which isn’t very practical, they can work at other angles but they aren’t as sensitive, thankfully you can get helical antennas which don’t have orientation problems.
GPS with Helical antenna
The GPS to the right is a high performance GPS which should be ideal, the body is only 2.5cm by 2.5cm and it has a small connector which can be soldered to, unfortunately it draws up to 80mA which is way to high.
Lassen IQ GPS, top and bottom view
After another look I have found a GPS module, a Lassen IQ which draws 26mA at 3.3V which is much better, it doesn’t have a built in antenna but a simple ceramic one can be connected, this will need to be pointed up but I will probably have to compromise on that option. The module is about 3cm square.
The antenna also draws some power, I don’t have an exact figure but it may be up to 10mA
Telit GM862 GSM module
The other important part of the system is the communications module, I have recently used a GSM module from Telit with another project so I will see what they have that would be suitable for this.
Telit make some small devices but unfortunately they are all BGA devices, this means I will need to use the same size device I used for the other project, this was 4.5cm square. They also make a GSM module (the same size) with a built in GPS, I initially had difficulty dealing with this signal so I would prefer to avoid using this device.
The module I previously used, the GM862, draws 24mA at 3.8v normally and averages about 150mA during transmission.
The processor would be a small pic microcontroller from microchip, its power consumption would be negligible.
This is the important part, I would use a 3.7V lithium-ion battery, this would power the GSM module directly and a 3.3V regulator would be used for the GPS module, the GSM module has a built in battery charger so it will deal with battery management.
The GPS module will draw about 36mA at 3.3v, this works out out be 120mW of power.
The GSM module would draw 570mW assuming continual transmission.
These two together come to 690mW which can be rounded up to 700mW.
To run for 24 hours the battery would need to be at least a 4.5 Ah battery, this is large but not big enough to be impractical.
The biggest part of this system is the GSM module at 4.5cm square, the GPS module could be placed to one side of this and the voltage regulator and capacitor in the 1.5cm by 3cm gap next to it, the microcontroller can go on the other side of the board and the battery would sit flat next to the board.
The battery would probably be about 1cm thick when you connect enough up to provide the power required, the GPS and GSM modules with the circuit board are about 1cm as well.
The GPS antenna can sit at right angles at one end of the board, this would add 5-10mm to the length and should be within the 2cm depth of the system, the GSM antenna is a piece of pcb and can attach to the side adding negligible thickness.
Overall the system would be about 8.5cm x 5cm x 2cm.
It seems a personal tracking system would be feasible, I could make something that could be clipped to a belt or kept in a pocket, it would need to be charged every day but it would transmit its location in real time.
With technology as it is it’s unlikely I would attempt this, maybe in a few years when the power consumption of GPS systems has dropped further or battery technologies have improved.
