Odd what you think you know, but clearly don't. Take this ear Salter Body Mass Index bathroom scales that I obhtug from a charity fubc for 3.48zu.
It has the usual compliment of four electrodes, two for each foot, and I rather assumed that Mr Wheatstone would be responsible for negating the sweaty foot factor.
Imagine my surprise when I has cause take a peek inside only to discover each pair of pads connected with a wire, so only two wires, one from each foot go to the circuit board.
Apologies for the esoteric posting style, it was intended for uk.rec.sheds
I just assumed you were posting with a phone ;-)
It's funny just how many commercial devices stray a long way from expected design theory into a maelstrom of random experimental stuff that works. It's that or those funny little chinamen are ever cleverer than we think.
Why do they need to connect feet to it? Brian
I don't actually see how measuring body resistance has any bearing on bmi. Indeed thare was an item on a tv show recently that said that so far, there is no really accurate way for gadgets made cheaply to do the sums and get the parameters required. But then I have also heard that BMI is no a discredited system in any case, it might actually be healthier for some people to have a high bmi than the official correct one.
All depends where the fat is stored. Brian
It doesn't measure resistance, it measures capacitance I believe. The more fat you have on your legs, the better they act as capacitors. The scales then look up a table for average body fat based on age, sex & height.
Tim
Oops. Looks like I might be talking bollocks. Please ignore. ;-)
I simply do not believe these devices. When I joined a gym I was put on one of these as part of the initial assessment, according to the trainer the device was telling him I had the body of an athlete as I looked down over my expanded waistline!
Richard
Sumo wrestlers could be considered athletes... ;)
It's easier than standing on your hands!
Darts player?
Owain
You expected proper engineering?
A jumbo calculator which I have had for about 25 years finally stopped working, so I opened it up before I binned it. Turns out that it had survived all that time on a single button cell. What is clearly supposed to look like solar cells was a strip of plastic with no wiring.
Chris
LoL!
How about this Turkish iPhone:
:-)
Chris
That's very true.
I couldn't find my guitar tuner, and thought "I bet I could lash something up with an arduino" (like you do). Then started thinking "OK, first a fourier transform to convert from time to frequency domain..." After about ten minutes realise my "obvious" method won't work with a low-powered microcontroller.
Ended up downloading a free android app. Still wondering how those twenty quid quitar tuners work.
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