Saturday, 25 April 2009

Whither LVLR?

I don't know what's going on with the LVLR project. You know how it is when you've got 99% of the resources you need to realise a successful project outcome but that missing 1% remains out of reach? No? Oh, well - it's really frustrating, that's what it is. Try it sometime - it'll drive you insane.

What is LVLR? It's a navigation aid for SCUBA divers, particularly those working in conditions of low visibility and those over-tasked with other equipment considerations. Yes, yes, there are plenty of underwater navigation aids on the market already but none works quite like LVLR, not even the impressive and highly desirable Heads-Up-Display (HUD) that was developed by Oceanic originally for military purposes, later versions becoming available for the technical/recreational diving market. Add to this the strong possibility that LVLR could probably retail at sub-£100 and you've got the kind of "pocket-money" item that many divers would buy on spec and then wonder how they ever managed without.

So what does LVLR actually do, precisely? I cannot give details here as this would compromise the patent application. Let's just say that LVLR does something that no other product can do; it's all in the software and the peculiar Human-Computer-Interface (HCI).

I went diving yesterday with my good dive-buddy Richard, just to keep our skills up-to-date and to have a bit of fun. At the dive site an unusually heavy algal bloom was taking place and, at about 1m, visibility was truly appalling (unless you're a Police diver, in which case I suppose 1m visibility is something of a luxury). We got lost. 13 acres of murk and we didn't know where the hell we were (except how to get back, of course; at this particular dive site, North is almost always good and gets you close to an exit or something else you recognise). Eventually we found what we had been looking for - a 1910 steamboat lying about 23m deep. We actually bumped into it before we saw it. It would have been fun to stick around a while and explore the boat but we had used half our air getting there and that's when it's time to turn back - penetrating the "wreck" would have been foolhardy in the extreme. Now, if we'd had LVLR, we would have got there sooner and our more controlled dive-depth profile would have saved even more air...

So, why is LVLR still not realised six years after its initial conception? The missing, vital component is a miniature pressure transducer of the kind found in dive computers and some dive watches. I remember when these were readily available on the Internet - I wish I had purchased a few back then. Now there is no sign of these particular devices anywhere on the Internet, though I know they exist. I suspect that certain OEMs have acquired exclusive rights to the source, just to keep would-be competitors at bay. I wouldn't care if I were a competitor but I'm not - there is nothing like LVLR out there. LVLR is truly unique...

An early prototype of LVLR sits in its prototype waterproof housing, awaiting the arrival of a suitable pressure transducer. Will the sleeker, slimmer production version ever see the light of day? Only time will tell.

If you have a shagged-out old dive computer or dive watch containing a pressure transducer of the type described, please contact the Secret Laboratory!

Saturday, 18 April 2009

Blues Stomp Box - complications

OK, so the Stomp Box MkI didn't quite work out as planned. I didn't expect it to be perfect first time. One-off projects like this evolve over time.

The first fault was with the LED power indicator. Personal memo to self: never connect a self-blinking LED across the power input of an audio device, unless you actually want that Floyd-style heartbeat in the background all the time.

Second fault... I had such faith in that piezo transducer! I was so certain that, being a contact device, it would be relatively immune to external noise and would pick up only the stomp from the box. I was right, but in such a wrong way. No feedback problems (hurrah) but every last detail of sticky shoe sole issue was faithfully fed to the amp, making it sound like an octopus making love to a biscuit tin. Boom-schluppp Boom-schluppp, etc. In desperation, I added a layer of rubberised carpet to the top of the Stomp Box. This made it sound like an octopus trying desperately not to be discovered making love to a biscuit tin.

The blinking LED had to go. I replaced it with one of those low power plain jobbies with a built-in resistor, designed for direct connection across rails. So far, so good.

The piezo element had to go. I replaced it with a dynamic element from a crap old cassette-recorder microphone, embedded in foam packaging.

As far as I was concerned, I now had a Stomp Box! I shoved it through my 100W Laney Linebacker, took the top-end off and was pleased to hear a satisfying Whump Whump Whump coming through.

However, everyone's a critic, so it seems. On its first night out, the Stomp Box was still deemed to be too "toppy". Some said that thicker carpeting or even neoprene rubber casing might help. Others argued that an active low-pass filter might be the solution (sledgehammers and nuts spring to mind). Personally, I suspect the ability of the performers. Just because it's called a Stomp Box doesn't mean you can just plug it in, stamp on it and expect to sound like Catfish Keith on day one. These things need learning...