Chris Elleman Technical Stuff

6 Sep/12 Off

Pause and Reflect

I'm not going to be posting for a while due to external factors, however, you can still follow me on twitter using the button below or just use the panel to my right -->

I have also fixed the Subscribe to RSS feed link at the top right of the main site, using this project: - when I do start posting agin, your RSS reader will see it stratight away.

26 Aug/12 Off

The Future of Wind Power?

I saw this a while ago, I thought it was a fantastic idea, basically instead of the wind farms which are being thrown up by the government and seem like a bit of a waste of time; this idea looks revolutionary, a wind turbine which flies like a kite - this means it can fly higher and take advantage of the higher winds, it also functions much better at lower wind speeds.

The companies site goes into a lot of detail, I recommend a look: Makani Power

25 Aug/12 Off

S3 Site integrated with Home Raspberry Pi

Building on the success of this website and it being served out of Amazon S3, I have decided to re-jig my home server setup. My old server was a small PC which sat in a cupboard and did things like media serving (off a USB HD), DNS, DHCP, SSH server, etc and in total it drew around 25W to power it, which generated some heat when it was sat in a cupboard - not very good now that the weather has been a bit hotter.

I have replaced that server with a raspberry pi (drawing around 0.5W) to deal with the always on tasks as described above, the raspberry pi is capable enough, but if I want to download something really quick I just can't get the transfer rate out of the raspberry pi; so, I have kept the original server and used wake-on-lan to power it up only when needed to do some heavy lifting.

This means that the raspberry pi is acting more like an orchestration server, so if I want to build any apps for home, then it would be good to seperate the presentation from any computation, for example, I have an app to track my media and do some transcoding, I'd like this not to be served directly from home if possible and I'd like to leverage facebook oauth, so I've put together the solution below which makes use of S3 to serve static assets and my home raspberry pi as an API endpoint.

This design has several advantages:

  • de-coupled presentation from computation - allows for future scaling etc
  • leverage external identity provider - takes the pain away
  • cname home broadband dynamic DNS under application domain to give access to cookies etc - unified secutiy model
  • energy/cost saving moving from traditional server to raspberry pi
  • bandwidth costs are much lower - high volumes of data are served by my home broadband and not from S3

24 Aug/12 Off

AWS Hosting 1 Month In

I've been hosting my site for 1 month on AWS, and what do you think my Amazon bill has come to?

A massive $0.76, that's right 76 US cents, amazing really, but when you think about how much traffic and space my site uses compared to some of AWS's customers, then its no wonder really.

In conclusion, the experiment has worked and this site will be on S3 for the foreseeable future.

23 Jul/12 Off

Jekyll AWS Hosting

Well, that was a marathon!

This site is now live on AWS Simple Storage Service (S3) and its come out rather well, I think. The biggest challenge was getting the theme to look right. Learning the templating (liquid) and markup (markdown) language was quite straightforward.

I have created a new page with some additional resources I used for adjusting the formatting resources.html.

This should save me around $7/month which is always nice :)

7 Jul/12 Off

Wordpress to Jekyll?

As you can probably tell, I'm running my own version of Wordpress which works fine for my needs, however, this causes me some concerns; firstly, security, Wordpress is great, but its dynamic and written in PHP, so anyone can have a pop at hacking the site - not good. Secondly, I have to host the site, and because it requires some compute power, its costing me $8/month for a Virtual Private Server in the US; Finally, scalability, I doubt that this site will ever be very popular, but if it ever got Slashdotted, or re-tweeted by someone like Raspberry Pi, then I'm in now doubt that my site would be on its knees in seconds.To this end, I 've been looking at alternatives, and hosting a static site on Amazon S3, which looks very cost effective and scalable, in fact I have been hosting another site on Amazon S3 and haven't incurred any cost yet, because the traffic is so low :)

Useful links:

4 Jul/12 Off

Turn a Raspberry Pi into a Laptop with a LapDock

Using a Laptop Dock for Motorola ATRIX 4G, along with some adapters:

23 Jun/12 Off

Science Videos YouTube Channel: brasspup

Science and illusions video site: