MindFeed

Wooo! Today I got my first live feed working! A few teething issues which I need to iron out but on the whole it works just as expected.

Today I received my T-Mobile sim cards that allow me to use unlimited internet on my mobile for £2.50 for 5 days. This great for my project so I can try live updates!

I have also added to the XML specification for recorded data the device type of the found bluetooth devices.

I have also added a GPS signal strength bar to the mobile application which uses DOP values to generate it.

I shall shortly be working on getting a live feed working to put everything to the test!

Things are getting exciting now

Today was a day of testing where by I found an error with my GPS string handling. After much research I have found the proper way to parse all of the different GPS strings correctly. I have also realised the need to convert between DDMM.MMMM to decimal degrees which is DD.DDDDDD and have made my own functions in the mobile client to do this for Longitudes and Latitudes.

From these GPS strings I have also obtained bearing readings and whether or not I have a valid fix at any one point in time, which is extra data I now can inform the user of.

I have also tidied up all the client code with good indentation and decent commenting. Modules have been used to good effct to make the maintainability of the code easier.

I have also implemented an averaging algorithm when the longitudes/latitudes are updated to reduce the effects of gps errors. This averaging is only used when the resolution (under the options menu) is set to all data or 1 second. If this is not the case it uses the original method. My reason for doing this is so that if you have an update say every 10 seconds, the average from the last GPS point to the current one is half way between. In a period of 10 seconds this could be way off your ending way point. However if you are using all available updates or every 1 second this is likely to only be a couple of meters away from the goal which is fine.

I also need to try and implement some of my post processing features in my PHP script into the live mobile client to save data processing later on the recorded data.

Woohoo!! I have almost completed the Windows Mobile mobile client.

It now has:

• Easier to use interface and it is sexy too
• User feedback area - so the user knows what is going on at any point in time and alerted of failures eg if unable to connect to GPS and such
• GPS scanning
• Bluetooth Scanning
• Advanced settings configuration
• Debug form to see all important received data for bluetooth and gps - I can see at a glance if anyone is stalking me if they are carrying a bluetooth device

To do:

• Need to implement live GPS updates for LiveMindFeeds. Will tackle this next.
• Need to integrate time intervals for recording under options with the rest of program.
• Implement the loading of saved options on start up!
• Integrate post processing features when capturing live data eg dont bother recording points close together or too far away etc.

Today I have converted the template I made for MindFeed into a lovely XHTML template. All images have been optimised for maximum quality but minimal size and the resulting template including all images and code is only 84Kb in size which is great for fast downloads and to keep my own bandwidth minimal and thus keep costs down.

Next on the todo list is to do the same process for profile pages and any other page on the site that will have its own unique style.

You can check out my XHTML code at http://www.mindfeed.co.uk/

Today I have integrated my blue tooth scanning code with the rest of my MindFeed mobile client code. However when I scan for bluetooth devices, it causes the rest of the program to hang.  I need to figure out how to get it to scan in a new thread or such so that the rest of the program works still! We shall see how this goes… however the scanning does work- just not very elegantly.

Wooo I have spent the whole of today developing the front page for MindFeed.co.uk, which you can view at you guessed it, http://www.mindfeed.co.uk/

This beauty of a design has taken me 8 hours to complete but was well worth it! Many hours spent hunting for meaningful stock images too! Finally we are getting somewhere. Now to phrase all the wordy bits so it actually makes sense to a non techie, and to design the other key parts of the site such as profiles etc.

A good productive day though. *smiles*

Today I have been tidying up code and the appearance of the mobile client to make it simple to use and provide logical feedback on what is going on - so the user knows the program hasn’t just crashed and is in fact doing something etc etc. Below are some of the mock ups of the GUI:

Well after much searching I did find a free open source compression library for .net that works really nicely. Well, kind of.

SharpZipLib compresses files just as it says on the tin and can decompress them too, however the files cant seem to be read by standard other programs - including my upload mechanism to my web server! I believe something to be wrong with the format of the file. I need to look into why this is and see if it is fixable, else write my own library as originally planned.

*fingers crossed*

Today I embarked on an epic GPS recording session to really push my program to its limits by taking a train journey to London and back. Reaching a top speed of 174KMPH I can safely say that my system is robust to both fast and slow moving people!

When plotting my results using my mapping algorithm onto Google maps, I realised I needed to increase some of my upper bounds for distances between two points that were acceptable due to the fast speed of the train, but this was expected.

Accuracy was very good, keeping very well to the train track and for 2 hours of constant recording without compression the XML file size came out as 1.2Mb which when compressed can be bought down to about 100Kb.

I was also quite surprised to see GPS signals being received very nicely even inside the train away from the window which is great news too. GPS is now in a good usable state, which leaves me with the Bluetooth scanning to perfect and then I can finally develop my back end for the MindFeed website and its fancy associated services!