About a year ago I bought an OpenBench Logic Sniffer, an open-source (both hardware and software) 32-channel 200Ms/s logic analyzer. Dirt cheap ($50) and very cool and useful, some software present in debian (sigrok) and the standard client (in java) isn't shabby, either. Of course it came without a case, and of course I couldn't leave it like that.

Here's where my genetic inheritance (a slight dose of pack rat) comes very handy: I don't throw things away lightly if I can see a likely future use for them. I very much like repurposing stuff in unexpected ways (eg. small bottle of nail polish remover plus pipette from the hair potion plus spade drill = small bottle with pipette for contact lens fluid when camping, or: dishwasher rinse aid bottle plus yet another pipette = oil can with applicator for lubricating the bicycle).

Because of this tinkering bias I really detest planned obsolescence and the thinly disguised downcycling spiral that we're sold as "recycling" all the time...and I'm extremely pleased whenever I find another elegant new (and unintended) use for something others call "disposable".

Hence I didn't buy a project box or case for the logic analyzer, but rather dug through my Box of Boxes, Bottles and Useful Plastic Things. I didn't have to dig deeply; after 5 minutes with a scalpel and the hot glue gun I had the OLS mounted in this perfect enclosure:

 logicanalyzer recycled casing

The box once held adhesive plaster strips and was simply way too useful to end up in the trash.

The analyzer itself has already proved to be a super-useful new member of my electronics tools toolche^Wzoo (other members: a Tektronix 2246 oscilloscope and a HP 3312A function generator).

The Tek is not a storage scope, so diagnosing complex and/or non-repeating signals is pretty much a no-go. But I needed just this kind of capability to fix yet another problem bugging me.

Some of you may remember this description of "dervish", the custom head unit I made for my bedroom music player, which provides an interface between a PC and an LCD module plus IR remote control reception via just one serial line (and a PIC, of course). The dervish is housed in a repurposed transparent floppy box, by the way :-).

The dervish had been whirling fine for the last three years, but suffered from occasional runaway phantom IR repeats that I couldn't track down. Two hours with a breadboard, an IR receiver module and the logic analyzer finally made me realize that the remote control I'm using doesn't follow the specs very closely, and really screws up the signal timing when the batteries run down. Another hour later I had tightened up the code for better rejection of dud signals and all is well again.

[ published on Sat 30.04.2011 15:21 | filed in interests/tinkering | ]
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© Alexander Zangerl