Hi, Thanks for the reply. However, when I remove the D22 diode, the LEDs still blink when powered through USB. Why is that so?
Best Regards, Xi 2007/9/27, Michael Schippling <[EMAIL PROTECTED]>: > > Boy, that's a tough one...I'm not entirely sure without looking up all > the chips but I think when powered by the USB it goes sorta like this: > > page 3 top-left "USB Interface" > U22 pin 4 -- power from host -- becomes U_VCC > U25 TC55RP33 -- does some magic to make -- P_DVCC > > page 3 top-right "Mote Power" > P_DVCC -- goes through D22 to become -- VCCin > (I'm not clear on the use of a Zener here, if that is what it is...) > > page 1 top-right "Power" > VCCin -- goes through L2 to become -- DVCC > > But, if as you say, ( PWR_CONN) U4 pin 1 - VCCin - does not connect > to D22 pin2 - VCCin - then all bets are off. Make sure you got the > right pin of the diode when doing the continuity check, or the > right polarity if checking through the diode... > > MS > > xi zhang wrote: > > Hi all, > > I'm trying to profile the power consumption of the TelosB mote when > > powered from USB. I've looked at the schematics of TelosB but I could > > not figure out how the DVcc is generated when powered through the USB. > > In addition, I would also like to know where is the Vccin (which is fed > > to diode D22) generated since a short circuit test has shown that it is > > not from power supply U4. > > > > Thank you very much! > > > > Best Regarts, > > Xi Zhang > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > Tinyos-help mailing list > > [email protected] > > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >
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