Homebrew Remote Switch For Canon EOS-350D

I’ve found myself needing a remote switch for my Canon EOS 350D camera recently. The official Canon product is the RS-060E3, but at 25 UKP that seems a bit steep.

A quick search on Google, and I came across Chantal Currid’s page on making your own remote control.

It turns out it’s actually really simple to build my own, so that’s exactly what I’ve done.

The EOS 350D uses a 2.5mm stereo socket, the three connections being ground, shutter control and auto focus control.

A quick trip down to the radio studios are work produced an old stereo cable from their junk box. This had a 3.5mm stereo jack plug on it. Next was a trip to Maplin on Great Portland Street where I bought a 3.5mm to 2.5mm adaptor plug, a handheld box, a red push to make button, a black push to make button and a toggle switch.


The wiring is simple, and details are on Chantal’s page on the theory of operation.

The toggle switch is used to latch the auto focus. The black push button is a momentary connection to the auto focus for when we don’t want to use the latch. The red push button is used to trigger the shutter release. If the toggle switch is on, this keeps the shutter open until the toggle is switched back. Very handy for those long “bulb” exposures.

Here’s the wired up box.

wired up canon switch

And here’s the final finished (and working) remote switch.

finished switch 1

finished switch 2

finished switch 3

finished switch 4

It should be possible to do more interesting stuff with this. How about one of Maplin’s IR beam kits, that we can use to trigger a shot if an invisible IR beam is crossed? Or even fitting in one of their remote control units? There are a lot of cool ideas to try.

Introducing Acme::Terror::UK

There is a lot of fuss in the press at present about the current terrorist threat to the UK.

The government has put the current threat level on a few of it’s websites. These are…

The US government has had provided it’s threat levels to the public for a while, and there are various ways to access this, incuding a Perl module called Acme::Terror.

Now the UK has this information online, I decided to provide the UK with it’s own version of this Perl module, which I’ve rather originally decided to call Acme::Terror::UK.

It’s really simple to use the module. For example, this small bit of code will fetch and display the current UK threat level.

use Acme::Terror::UK;
my $t = Acme::Terror::UK->new(); # create new Acme::Terror::UK object
my $level = $t->fetch; # fetch the current terror level
print "Current terror alert level is: $leveln";

The code goes off to the home office site behind the scenes and screen scrapes the page to get the current UK threat level as the UK government doesn’t currently provide and automated feed of this information. This makes the module vulnerable to any design changes on the page, but it works for now and that’s the main thing.

There are 5 levels, these are…

  • CRITICAL – an attack is expected imminently
  • SEVERE – an attack is likely
  • SUBSTANTIAL – an attack is a strong possibility
  • MODERATE – an attack is possible but not likely
  • LOW – an attack is unlikely

At the time of writing, Acme::Terror::UK informs me the current threat level is SEVERE.