Background Info:

This section rambles about why I wanted to build a Shard cam, jump to the Design/Build section if you can’t be arsed for the reasonings.

I live in south* London, which means that the everywhere I look the Shard stands over me. Now its reported that a flat in this tower of Babel will cost north of £30 million quid. Lets hope the lifts work.

This wonderful splash of cash got me thinking, basically you buy this flat for the view. Now living in Britain as I do, I know that the weather is not really design for long distant views. This got me thinking; if its grey and raining for a day, how much does it cost? Quite a lot as it turns out:

£30,000000 / (365 *10) = £8230 a day.

That’s right, rain costs Eight grand a day

Lets just go over those figures a little. We assume a flat costs £30 million, The Telegraph claims its up to £50M, however the estate agents seem to differ and peg it at around £20M. I’ll do what economists do and guess a number and swear its based on an accurate model. Like wise I assume that the average nouveau riche nonce will keep the flat for about ten years (I assume they’ll either die in a car crash, coke overdose, or have to sell it to fund an expensive vice of some sort)

If we plug those numbers into my proprietary financial model algorithm, we see that £30M spread over ten years equates to £8230 a day (with rounding). I also assume that you buy this type of flat for the view** Dividing it further, each rainy hour costs around £342. Its even higher if you don’t count the night time.

So why do I need a webcam? Well I want to find out how often the shard is obscured by rain, and therefore how much money has been eaten by the British weather and then laugh at the knobs who splashed so much cash.

Design

I want the pictures to be of decent quality, cheap and low power. I selected the following:

• Logitech 9000 webcam
• Raspberry Pi CPU
• pibow case
• cheap USB thumb drive (8 gigs)
• Aluminum case (like this one)

This guide has an excellent set of instructions for unboxing the logitech 9000. He’s carefully documented all the steps needed to strip the webcam to the core. I stopped at step 11, as I’m not going to fiddle with the optics.

Pictures:

There are two important lessons when designing an outside electronic device:

1. An IP54 case which claims “Water splashing against the enclosure from any direction shall have no harmful effect” is invariably telling porkies
2. Clingfilm and a light mineral oil is rather good at rain proofing things

Those of you who’ve read my exploits with Outdoor sensors, and GPS loggers will have seen me briefly describe the deficiencies of IP rated cases. Basically if they are not rated for full immersion then they are most likely powerless against rain. In the above picture the oily clingfilm is marked as number 2.  The reason why I’ve annotated the wire is because water is very good at running down wires. When it hits something solid like the webcam case, it sit there in a nice pool.

In this image:

1. Autofocus lens, it is suspended on a tiny linear motor and will move if you touch it. This means you have to be careful that its not touching the case.
2. Assorted fluff derived from the sponge that holds the PCB in the case.
3. Sponge guide, aligning the webcam to the “peep hole”. An excellent case for using shapeways to 3d print a jig to hold it solid.
4. Very bright LED, with a bit of tape to stop the light leaking inside the case
5. Microphone (currently unused)

In the above image:

1. The glass lens protector from the original case, super glued into place.
2. The webcam slightly on the piss.

Next steps: Software for time lapse! (also analysis)

Footnotes:

*or Saaaaaaafff laaandan in a more idiomatic form
**its in southwark, its really high, buffet by winds and rain, and shakes like a tree, its not exactly trinity square