On 10/28/2010 5:47 PM, RussellMc wrote:
> Unlikely but -
>
> Anyone willing and able to deliver the following to me by 8pm tonight.
> Price should be low :-).
> Hardware returnable if desired if I and it survive.
>
> Joe ...? :-)
>
>
> Logging accelerometer, 3 axis.
> 5g max per axis.
> Maintain RTC. Linear counter OK.
> If g on any axis exceeds 1.2 g OR if  g in any direction other than the
> highest one (not axis), orthogonal to the highest  direction  exceeds 0.2=
g
> then
> Log peak g in each ?0.1? second time slot for 10 seconds, plus time.
>
> Modify spec to be useful.
> Logging time =3D 20 days.
>
> AIM:  Measure g forces experienced by baggage - especially during airport
> lugage handling.
>
> I don't really expect one by 8pm.
> I must build one before next trip. !!!
>
> I posit that they have bag throwing, booting and stomping competitions.
>
>
>   Russell

I just built one of these yesterday and am presently debugging it.=20
Sorry, no RTC on mine but you could add that.

Source: Sparkfun, all the way.

I bought a PIC development board, a 3 axis accelerometer board and a uSD=20
card logger that records TTL serial data.  I'm recording 3 bytes every=20
ms; a bit faster than what you need.  They do have RTC boards as well.

The accel board has four ranges: 1.5, 2, 4, 6Gs.  I built it in a day=20
after receiving the parts from Sparkfun; I imagine you could do as well.=20
  Total cost is around US$100 or so not counting slave labor time=20
assembling it and coding.

I think that you should probably try to get something in the 25 - 50 G=20
rating on the accel units though...


Accel: SEN-00252
PIC:  DEV-00762
SD logger: DEV-09530

The PIC board is meant for usb operation and pulls 50ma; something else=20
would be a better choice.


--=20
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