I'm forwarding this from tinyos-help to tinyos-users so that anyone who may be interested in sensor callibration and whatnot can read it.
-kw ----- Original Message ----- From: "Bruce Cannon" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, June 23, 2002 3:51 PM Subject: RE: [Tinyos-help] Photo Sensor > I think it might work for each mote to do an initial calibration read in absolute darkness and use > that value as a factor in reference to some fairly arbitrary standard/nominal value. They could be > programmed to check for a calibration constant on powerup, and if clear do the calibration reading > and store it. If you program them that first time in a light-tight box, they'd be set until you > changed the sensor board. > > It might be nice too for all sensor boards to have onboard eeprom for calibration constants for each > sensor, so they could be independent of the motes. > > Bruce > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED]]On Behalf Of Kristin > > Wright > > Sent: Friday, June 21, 2002 3:02 PM > > To: Rahul Gupta; tos > > Subject: Re: [Tinyos-help] Photo Sensor > > > > > > I asked Alec Woo about this and here is what he had to say: > > > > >It's a shame that the manufacturer doesn't have the > > >specification as well, and currently, we don't have any > > >calibration process for it. > > > > > >The variations seem to be more significant for those brown > > l>ight sensors as compared to the gray ones. Xbow uses the > > >brown ones since they were in stock but this results in more > > >variance on our sensor data. > > > > > >alec > > > > ----- Original Message ----- > > From: "Rahul Gupta" <[EMAIL PROTECTED]> > > To: "tos" <[EMAIL PROTECTED]> > > Sent: Tuesday, June 18, 2002 11:03 AM > > Subject: [Tinyos-help] Photo Sensor > > > > > > > Hi, > > > Is there any document regarding the sensitivity and other > > > characteristics of the photo sensor on the mica sensorboard ? I observed > > > that when different sensorboards are connected to the same mote, the > > > light readings given by them are different even when placed at exactly > > > the same positions. Also each sensor gives different changes in readings > > > when placed at two different locations. > > > > > > Is there a work around to somehow make the readings concur ? > > > > > > Thanks, > > > Rahul > > > > > > _______________________________________________ > > > Tinyos-help mailing list > > > [EMAIL PROTECTED] > > > http://mail.Millennium.Berkeley.EDU/mailman/listinfo/tinyos-help > > > > > > > _______________________________________________ > > Tinyos-help mailing list > > [EMAIL PROTECTED] > > http://mail.Millennium.Berkeley.EDU/mailman/listinfo/tinyos-help > > > _______________________________________________ > Tinyos-help mailing list > [EMAIL PROTECTED] > http://mail.Millennium.Berkeley.EDU/mailman/listinfo/tinyos-help > _______________________________________________ Tinyos-users mailing list [EMAIL PROTECTED] http://mail.Millennium.Berkeley.EDU/mailman/listinfo/tinyos-users
