Ed's World

If you’re developing plugins for RSA, you’ll probably have one RSA open and a runtime RSA, both eating huge amounts of memory. To reduce the memory footprint, I’m using Eclipse to develop, but still launching a runtime RSA.

To do this, install RSA and eclipse (separately), then in your eclipse:

Install the JRE:
1. Windows > Preferences > Java > Installed JREs
2. Add c:\Program Files\IBM\SDP\jdk\jre
3. Tick its tick-box

Set the Target Platform:
1. Windows > Preferences > Plugin-in Development > Target Platform
2. Browse for c:\Program Files\IBM\SDP
3. Tick “Build target platform based on the target’s installed plugins”
4. Click “Reload”

Running as RSA
1. Run > Run Configurations
2. Change the Run as product to: com.ibm.rational.rsa4ws.product.v75.ide (or equivalent)

Tada! I’ve found I get far less out of memory errors and things are generally quicker.

On the 17th April I set off to the Black Mountains for a weekend solo hike, wild-camping overnight, to gain more experience for the “Scout Terrain 1 Assessment” and “Walking Group Leader Assessment”.

Day 1 was a 25km route (horizontally), scarily that doesn’t include 1.1km ascent and 800m descent – very knackering, but I did rescue a stray dog on route!

After eating my home-made boil in the bags and waiting for it to get dark enough, I put my camera on my jumper on a rock (there was no way I was going to carry a 3kg tripod around the place), and these were the (edited) results:

For those that care, the waterfall image was taken first, with an exposure of 30s at F9, ISO 100.

The tree was taken 20mins later after much experimenting, with an exposure of 4 minutes, F9, ISO 100. This meant there was long enough for the stars to streak across the sky. I felt this distracted from the photo, so removed them – you can see them in the original out-of-the-camera image on the right (there were even more of them after tweaking the brightness levels, but you get the idea). I didn’t have the patience to enable the noise reduction function on the camera – the one where it takes the photo, then takes another photo of black for the same length of time – in hindsight, I wish I had, but hey!

Both images involved painting the area that I wanted to show up with a super-bright LED head-torch. With the waterfall image, I set the exposure to 30s, and quickly walked above the waterfall to light the area around the top, then quickly came back to light the actual waterfall. The tree shot meant using a (tempermental) shutter-release cable (£6 from ebay, so can’t expect much more), and sitting behind the camera moving the torch evenly over the tree.

So that was fun. I went to bed and woke up in the morning feeling sunburnt and knackered. Day 2’s route was a mere 16km, this time descending a total of 820m and ascending 435m.

Really can’t complain waking up here:

In the move to put as much of my house onto twitter as possible, MythTV was the next victim. I’d previously made a PHP script that sent MSN alerts, but now I don’t use MSN, it needed a revamp.

I knocked up a small PHP script that grabs the backend status, finds what is being recorded or watched, compares with the previous run, and sends a message to twitter using wget.

To use it, grab the script, change the username/password variables, chmod +x it, and then add it to your “Startup Applications” or equivalent if you’re not using Ubuntu.

I’ve recently created a new website for my scout group, Highfield Scouts, and have put up a google calendar. More out of a challenge than a real need, I’ve knocked up a script that uses the Google Data API for PHP to query my calendar feed, grab the next event, and make a fake handwritten postit note. The script runs every hour to keep the images up to date.

I’ve made a little markup system so that the whole postit can be a link, and the time and location can be overridden (child protection malarky – can’t just put a time and location for some things!)

It’s all written in PHP, using the GD graphics features to put the text on a background image. If you’re interested in the code, comment, and I’ll give it to you (if you link to me!)

If you have HTML/javascript files sitting on your harddisk and you want to open them in firefox and actually use the javascript, you need to change one simple setting.

First, go to about:config (just type it in the address bar and hit enter)

Then filter for “origin”.

Change “security.fileuri.strict_origin_policy” to false.

You should now be able to use local javascript files.

Since writing “Get number of unread posts from google mail”, I realised that I didn’t care about a lot of emails that I get on a regular basis, things like ebuyer emails, stock-market alerts etc. I only want to be notified when I’ve got emails from real people.

By applying a “Newsletters” label on GMail to all automated messages by filtering messages, I can now see how many unread emails I have, then subtract the number of unread newsletters I have, and flash the ambient light that number of times.

Grab getGoogleMail.sh, change the usernames and passwords, and change “Newsletters” to whatever your google label is. Then use the $count variable to do whatever you want.

Something that drives me nuts is every so often there’ll be an accident on the M3 or M27 and the entire surrounding area will be flooded with people trying to avoid the deadlock, only to find they’re on a tiny road with thousands of other people. Yes, I could check the traffic websites each morning, or do some intelligent parsing of traffic RSS feeds, but the first option requires effort before 9am (not going to happen), and the second option is never going to be reliable enough – it’d be too hard to programmatically determine how bad the conditions on the road really are.

Read more…

In the struggle to find more cool things to do with the arduino, I thought I’d do what someone on twitter had done, make an “Ambilight”, an ambient light behind your TV that colours whatever is behind your TV the same colour as the average colour on your screen – pretty cool!  Some Philips TV have this, but I’m not willing to spend extra on that (and I have a TV).  I read Szymon Kobalczyk’s Blog and thought I’d give it a whirl.  Currently I’m using one of my existing BlinkMs, but I’ve ordered two RGB LED strips and the necessary (hopefully) components from farnell.

The core idea is:

• Run “Boblightd”, which monitors the screen (excuse the pun) and calculates the average colour, passing it to a program that sends the message via serial to…
• An arduino listening for colours, and changes the colour of the BlinkM/RGB LED strip accordingly

This is the result of mine on my computer monitor, looks much better in real life (skip to 30-40s for best demo). Will be even better when the RGB LED strip arrives – that’ll be going behind my 42″ TV downstairs.

Read more…

So, after yesterday’s Pinewood Derby with funky racing traffic lights, I looked for a simple, quick photo album tool to display the photos, and stumbled on Piwigo, which looked reasonable and the whole “Simple powerful” philosophy seemed to match what I wanted.  So, I downloaded the single php installer script, which automagically downloads the latest version and installs everything.  So far, so good.

Now to actually create an album.  Yes, pretty easy. Upload a file, not so easy, but doable.  Get that file to be shown – next to impossible.  This is the worlds most convoluted software I have ever seen!  To get a photo to be shown, you first have to syncronise, then go and create thumbnails – but wait, by default the synchronise does a dummy run, so go back and tick a tick-box.  Grr, really not usable.  So, I tried looking at the documentation (which goes against my beliefs of websites should never, ever, need any help – they should be usable) and even that is appauling!  It’s a wiki with a very poor navigation structure (if there is any structure), so impossible to find anything useful.  Turn to the forums to find others having the same problem, and being told to read the instructions…

Right, rant over, software uninstalled.

Plogger was the next on the list, the demo looked clean and simple – just what I needed (PHP/MySQL based).  Installed it in a couple of minutes, saw a test album had been created for me so uploaded a photo and job done – it was there!  Then spent the next hour cropping and adjusting the photos, uploaded them, and bob’s your uncle, I have a nice and simple photo gallery for the scouts!  The styling is very minimal, it’s designed to be part of a larger site, although there is one style that’s a little less minimal which I’ve gone for as there’s no “larger site” for this.

So steer clear of piwigo, and let me know if you have any recommendations…

Inspired by techcobweb’s SlotCarDuino, the night before our scout group’s “Pinewood Derby” (cars made by the kids from a block of wood race down a track, powered by gravity), I decided to make a traffic-light system, and an indicator to say which car one (as there’s sometimes a debate)!

So, in between power cuts (6 days on the trot of less than 8hrs of power per day), with only a few hours of awake time before the event, I dismantled my home automation system (no loss, given there’s barely any power for the heating) and connected up the breadboard, ambient lights and a couple of wires that will act as trip wires.  As there are no pull-down resistors, and I have absolutely no components, the trip-wire is connected to ground and then digital pin 3.  Running digitalWrite(3, HIGH); enables the pull-up resistor, so whenever the circuit is complete (i.e. car hasn’t driven through the wire) it reads 0.

The way I made the trip-wire was to stick one wire over the track, and rest it in a small uninsulated loop of wire.  A quick trip to the scout hut proved this worked, although was in serious need of some debouncing as the vibrations on the track caused the wire to jump around a little.

The main loop of the code is very simple, it reads the two trip wire readings, and if one changes it increments a winning counter.  If that counter is more than 7000 (fairly random number that seems to work), it turns that lane’s ambient light green.  After that happens, when the next trip wire is broken, the appropriate light goes red.

I stole the one component I did have, a switch, from the B&Q ambient light, and wired that up in a similar way to the trip wires.  At the start of the loop, it checks this value to see if it has changed (the button is a normal switch, not a temporary push-button), and if it has changed (after some debouncing), it resets some variables, checks the trip-wires have been reconnected (and if not, flash the appropriate light), then runs the red-amber-green starting sequence.

The kids seemed to like it, and other than the odd dodgy connection, and a particularly streamlined car going under the wire, it worked perfectly!!

Next year will be a little more high-tech as I’ll change the trip-wires to some kind of optical sensor, and possibly have one at the start of the race so we can display track times, speeds etc.  May even make an automatic releaser, we shall see…