Ed's World

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!)

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…