• NHI's uses the letters A-Z without I or O.
• NHI's start with three letters and end with four numbers.
• The last digit is a checksum.
• NHI's are assigned randomly. I believe hospitals have distinct sets ready to be assigned.
• Its possible for somebody to have multiple NHIs (first alphabetically is the primary).

The current Id. structure only allows for around 13.8 million NHI's. With a population of around 5 million in 2019 and the possibility of a single person being associated to multiple Id.s, I suspect NHIs in their current form wont be around very long.

References

(last checked 2023-06-06)

1. https://en.wikipedia.org/wiki/NHI_Number
2. https://www.health.govt.nz/our-work/health-identity/national-health-index
3. http://www.midcentraldhb.govt.nz/PatientsandVisitors/GeneralInformation/Pages/NHI.aspx

[EDIT]: Thanks to Chris W for pointing out a bug in my previous implementation. If the checksum is a '0' before being subtracted from 11, the NHI number is deemed to be invalid. This is now fixed in the generator.

Eventually I made the system a bit smarter to automatically turn on when I leave home and turn off as soon as I get back. Added to that, if anything moves while I am out, I get a message with a photo sent to my phone.

For fun, I also added an AI to my messaging system so if I get bored I can have a chat or ask it to do some pre-programmed tasks (such as shutting down systems on the network, taking a photo or changing its settings).

The whole system is built using:

• Motion[1]
• Python
• Nmap[2] / hping3[3]
• Telegram[4]
• PHP / SQL

Python Process

The heart of the system is written in Python and is set to run as a systemd process. It mostly sleeps and wakes up every so often (~10 seconds) to check for new motion events or messages from telegram.

Network presence detection

It turns out that its not easy to detect the presence of iPhones on a network. In order to save power they can be come rather quiet and uncommunicative to network chatter.

At first I tried to build something in Python but after it became clear it was no small task, I decided to delegate to a subprocess and run a system tool. Next, I went with a script using hping3[3] and arp tables. This still wasn’t fantastic so at the moment I am just using an nmap[2] ping. From my tests, this seems to work better than hping3 at finding the iPhone but my tests weren’t very scientific.

Monitoring

I set up a database to log network presence and created a small PHP script to graph phones on the network. In the example below, you can see the blue graph for my phone, pink for my girlfriends and green shows when one of us are at home (and the system is turned off).

2019-02-13

2019-02-14

2019-02-15

Messaging

Initially I build a messaging component using the free Telstra API[5]. This provided an API allowing me to send SMS messages to my phone when the system started up or movement was captured. I ripped this out when Telstra added more limits on the API and put more of a push to their priced model.

Telegram

After looking for a better way to do push notifications to my phone, I eventually settled on creating a Telegram[4] bot. This allayed my cost aversion, provided the push notification behaviour that I was after and opened up easier two way communication.

AI

I took an old copy of the A.L.I.C.E. AIML[6] bot and plugged it into my Telegram bot. Its hardly going to convince anybody in a Turing test but is still quite a bit of fun to chat to.

Image Capture

Motion provides a very easy to set up frame/video capture process on Linux. It has the ability to trigger actions when motion is detected but I have instead chosen to go with periodically polling its output for events and archiving captures.

References

(last checked 2019-02-16)

1. https://motion-project.github.io/
2. https://nmap.org/
3. http://www.hping.org/
4. https://telegram.org/
5. https://dev.telstra.com/
6. https://en.wikipedia.org/wiki/AIML

In the past, at the end of each week, I would have to try and remember how much time I spent doing different activities at work, so that I could record my time and bill the correct customers. This was a painful chore and sometimes required a bit of email archaeology, Skype log trawling and black-magic. Hamster allowed me to track my current activity with easy integration to my desktop and proactively record time instead of using retroactive sorcery.

I love the tool so much I thought I’d create my own PHP web based version which would allow me to use it from my phone and create all sorts of graphs. I have begun development on my tool and it is already usable. When I have a comparable set of features to Hamster, I plan to migrate my data across and open it up for other people to use!

I have created a puzzle trail where the goal is to find the cleverly hidden password and get to the next puzzle. The puzzles start out fairly easy and get more difficult as you solve them. I have tried to make them fairly obtainable however they will test logic and as you get further your knowledge of the internet, cryptography, steganography, control of temper etc. Its still very much a work in progress (although I can assure you they all do work, and there is a solution). You should never have to guess a password.

Inspiration for this has come from many sites such as Hack Quest and Project Euler which I have played around on for years. I have many ideas and the trail should be growing all the time. If you have any suggestions let me know! To get started and dive into the rabbit hole, you can use the form above or start here.

It was suggested that I make the bot tweet at sunrise/sunset which I thought was a cool idea and I may pursue it. I have looked for existing library’s to calculate these times on a day by day basis but all the (Java) librarys I found were not even close to accurate. It looks like its easiest to implement my own sunrise/sunset library; for the moment and I have an algorithm to implement and I could make use of some existing code I just need to convert.

If you want to follow my bot, it would love to have some friends and you can do so here. The Twitter Bots wiki page is here.

I decided it would be nice to get a copy of all the images for myself so I built a little scraper to do the job for me. I wrote it ruby so that I could take advantage of a great ruby gem called Watir. The script works by going through all desktop backgrounds, selecting the largest available and making a nice link in a separate text file. Afterwards a download manager like DownThemAll can be used to download all of them.

At the moment the script works in Windows with Internet Explorer but I am working on making it work with FireFox 3 in Linux. Its wiki page is here.

The rules of the game are rather unique and confusing, but it is somewhat similar to Minesweeper and has an amount of luck involved with it. Late last year I decided (it was suggested to me) to make a solver for this game and  I had a few iterations of working solvers, going from fairly naive to what I felt was pretty good. I have decided to start over again with a nicer version of the game and a boast worthy solver. Stay tuned or watch the wiki page for progress.

I have a small personal website, as you can see, that gets the odd visitor now and then. This makes me happy! so I like to know about it. There are plenty of statistic gathering scripts like Google Analytics that generate excellent aggregate data, but for my scale of website I prefer a more fine-grain monitoring. I use BBClone for this and it does an awesome job. Other than wishing it had the option for a SQL back-end, I always thought it would be great to have a real time notification of someone paying a visit.

Thus my java ApacheLogNotifier was born!

Using Java and Ubuntus port of NotifyOSD via the notification demon, I have created a small program to poll the tail of my Apache log and notify me whenever there is interesting activity. At the moment I ignoring localhost and bots, so that I can see if an actual person has just come to visit my website. There is a lot of work and refactoring to be done. My initial prototype is just a rushed couple of hours work (thanks to reusing the tail code from http://www.informit.com/guides/content.aspx?g=java&seqNum=226).

For more information and to get the code look at the wiki page.