Doing my OOK

I’ve a Maplin N96FY, a silver weather station with an external pole-mounted wind/rain/temperature combo that measures the weather.  This is logged to Weather Underground and via some NodeRED into a Twitter account.

I’ve long wanted to removed the internal LCD display which shows the barometric pressure and external weather, and just log directly from the radio mast but it has proved difficult to understand, and Jim Easterbrook’s excellent pywws program has connected and interpreted my data for a long time.  Now, I am getting USB lockups on my connection to the head display and wanted to see if I could read the data directly.

I’ve chosen a Jeelink at 433MHz (this is the frequency which my WH1081 reports on the nameplate at the back, some others transmit at 868MHz).  I believe that the 433MHz ISM band may go away in the future, but for now that is what I have got.  The next confusion is whether the Fine Offset device transmits in On-Off-Keying ‘OOK’ or uses FSK as apparently the devices have used a variety of these over the years.

I saw nRFmon, a little arduino sketch which does a good frequency spectrum analysis and tried it out – I can see lots of activity across the 433 band as shown below.  You may see some specks of activity in the narrow waterfall display (narrowed around 434 as that seemed the most ‘interesting’ area of the graph).

Screenshot from 2016-01-31 13-32-23

I now need to identify which may be my transmitter, and more importantly if it uses OOK or FSK protocol – at the moment I’m not sure how to determine which!


Where has the hope gone?

They say that the artists reflect an era better than the historians.  At least they should say that, because I just said it.  So there.  Anyway, even if it doesn’t hold true I was musing recently about the state of Sci-Fi, a genre that I enjoy.

Take a look at some books from the 1950s and sci-fi was full of rocketships, aliens, science and mostly things that wouldn’t really work (robots that iron your clothes, anyone?).  Some things were guessed at correctly, such as satellites and mobile phones. Others were complete junk and most likely will be forever – such as pills that turn into food, warping through space, and peaceful societies.

But what fascinates me the most is how the general tone of sci-fi movies has turned from the (sometimes) hopeful futures and admiration of science into horror, alien infestations, and general unease about the advances of science.  Now, I’m no lover of scientism and think that “-isms, -anities, and -ologies” get worshiped too much rather than the actual and individual (oh Plato, put your shadows back in the cave) but the whole swing from “science will save us” through to “science infested my bowl of cereal with these GMO parasites” thing is silly.  I’ve been browsing some online services such as Wuaki, blinkbox and Netflix trying to find some sci-fi that tells a good story rather than relying on the whiz-bang effects.  Things like Cloud Atlas at least tried to do something different, although I thought the book was more explicit what was happening so ‘got it’ quicker.  But why so much darned horror sci-fi?

Well done to those directors who have taken some PK Dick themes and turned them into good scripts though.  The madness of We Can Remember It For You Wholesale would never go well in a movie, so the various efforts by Arnie and co and later directors doing the whole Total Recall movies was great – so what if it wasn’t like the book!  I guess that I like the non-messianic movies best, those that either bring an everyman into a momentous event and get them through without invoking hidden powers or other nonsense, or those that take something classic such as The Tempest and re-dress it with sci-fi bling.  I’m off to watch a Russian movie from one of the Strugatsky brother’s books and hoping someone does another good Roadside Picnic one day.  Stalker isn’t bad, just a bit old.

Doin’ my H-T-P-C

The central idea of a Home Theatre PC is to build your own box that plays movies.  Names such as XBMC, Kodi, MythTV, Windows Media Center and so on float around the blogsphere and lists an impressive number of open source programs to do this.  The range is enormous and for each of the components you need to decide where your preferences lie along the buys versus build spectrum.  For example, there is a galaxy of cheap Android boxes which will connect to internet sources such as Netflix or Amazon and stream their content to your TV.  Heck, there are even TVs which will do that!

So why go to the effort to create your own?

Most of the people I read seemed to like the technical challenge and the openness achieved allowing them to add new services as they desired.  All that openness comes with a cost and the effort of Some Configuration Needed.  I particularly liked the components which could participate in the toolchain, so to speak, and even if they were useful as standalone services could also feed their results into other services.  So what services do you need?

Media comes from a variety of sources:

  • Physical media – DVDs and the like
  • Terrestrial digital transmission – also known as your tv antenna!
  • IPTV (stands for Internet Protocol television), which comes through the internet and can comprise
    • IPTV from the net, such as Youtube and other which are free
    • Online IPTV, such as Netflix for which you need a paid account
    • On demand IPTV that streams services to you, such as Hulu or Blinkbox or Wuaki, and for which you pay-per-movie

Each of these sources has ways of getting their content to you, and some like Netflix have their own client.  Each source will have a method to obtain that content, a way you can stage it, and perhaps a unique client that needs to be used to deliver it.  Feeds such as live TV require a TV tuner for example, while DVDs can be ‘ripped’ to home storage and later viewed. I settled onto a number of components to give me these feeds, a mixture of commercial and home-built:

  1. HDHomeRun by SiliconDust, to provide the live terrestrial digital channel tuners which could be piped around the home to mobile phones, computer screens or TVs.
  2. USB hard drive for storing movies.  I looked at Network Attached Storage devices but besides the Windows-only clients which some provide, the cost was prohibitive.  My movie collection ain’t that important!  So a 1TB USB drive attached to my home router was “good enough”.
  3. A Digital Video Recorder running on a single-board computer.  In this case I chose a Odroid C1+ and ran the VDR software on it to record live TV streams onto the network hard drive.  The Odroid is a very capable SBC and able to control a number of operations.  I used a variant of GNU/Linux and had a number of other things also running on this.  Warning: “Some Configuration Needed”!
  4. A front-end box running Kodi on a Raspberry Pi.  This was really simple to set up and everything is done using a wireless remote.  Much simpler than the Odroid PVR above, I’d rate this almost no-configuration needed.  If even this is too much, search Amazon for “android kodi tv box” and you can get some pre-setup TV boxes real cheap nowdays.

I’m still struggling on step #3, the PVR setup but other than that the whole thing just works.  I’m really pleased with what is possible with these little boxes.