On Tuesday 29 August 2006 09:55 am, Luis E. Palafox-Maestre wrote: > Hi, > > Is there a way of calibrating the onboard sensors on the TMote? I'm asking > this because I keep getting different readings for motes that are next to > each other, for instance I consistently get temperature readings that are > up two Celsius degrees apart.
Tmote uses the Sensirion SHT11, which is factory calibrated. It's data sheeet says its accuracy is +/- 0.4C @ 25C. I'm assuming the two motes are identical, sampling the sht11 at the same rate, and generally performing the same workload? Self-heating is a real issue; see the data sheet for more info. Sorry if this is too obvious, but environmental factors can be a pretty big deal. I just got a temp increase of 1.22C on the mote (not Tmote, but uses sht11) at my desk after moving it ~ 8" closer to my monitor. If you haven't already, you might try your test again, then swap the motes' positions and see what happens. Because the sht11 is tied thermally to the mote, it can take quite several minutes for temp readings to fully stabilize after a change. Steve _______________________________________________ Tinyos-help mailing list Tinyos-help@Millennium.Berkeley.EDU https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
