> -----Original Message-----
> Am I correct in understanding that this uses some sort of sonic
> triangulation?? That's an amazing bit of early tech!
> I see very little documentation on-line. Pass a note if you manage to
> get a youtube video or something online.
> I'd love to see this in action!
Exactly! It's actually not as complex as it might first appear - the device
knows when the pulse was triggered, and just has to look for that sharp impulse
of sound from each mic within a small timeframe after the pulse (because the
work area is finite), then time the arrival delay at each mic to find the
distance. It has a calibration routine to fine-tune measurements for the room
temperature (the manual says it's calibrated for 74F, I got pretty accurate
default readings at 68F here and spot-on after calibrating). I remember having
a Black & Decker sonic tape measure many years ago which bounced a sound pulse
off the far wall of a room and gave a fairly accurate distance reading (usually
within 1/8" iirc). My boss (who had a gift for giving things and people odd
name) referred to it as a 'wireless tape measure'. :)
I should have taken some photos of the PCB while I had it open the other day
checking component temperatures when I powered it on. My memory is terrible
but I think it had a 6502 processor inside. The layout on the board was nice,
with identical sections on the left and right for processing the signal from
each microphone, processor and other ICs at the front centre, power supplies
for low and high voltage (for the spark) at the rear. I also got a printed
manual in nice shape which I suppose should be scanned for archival purposes.
Interestingly, the manufacturer seems to have put a great deal of faith in the
T102's memory battery. I've been playing around with the software, going
through the examples in the manual, and it has a lot of features such as the
ability to define component items that would go into a job you're costing out
based on drawings (for instance, calculating rolls of roofing material based on
square footage, or calculating number of 2x4 studs needed based on wall lengths
and a specified on-centre spacing) and then automatically calculate prices.
However, it doesn't write any of these parameters or figures to a file, it just
stores the variables while it's running and if you hit the rear Reset they're
gone. The user manual doesn't address what to do if the machine gets reset (no
mention of CALL 63012) and in fact just tells you to turn the machine on and
off and not to worry because all the parameters and measurements you've stored
will just stay intact. Although they've put a silver DIRE WARNING sticker over
the memory power switch opening, they didn't cover or disable the Reset button
so it's entirely possible for the user to fat-finger it and find themselves at
the main menu screen. I guess that's why they litter the company's 1-800
number throughout the manual?
Making a video for youtube about this machine... an interesting idea. I'm not
sure I could hold a candle to Hey Birt! or some of our other youtubers on here,
but it's something to think about. :)
jim
