Hi Jianxin, The point of the PV_REG connection is to avoid soft power, or LDO regulator power loss for a high powered expansion or an expansion that needs a battery backup (like GPS).
If you use the PV connection on pin#1 (regulated 3.0V from Shimmer board) it will follow the power state of the Shimmer. Otherwise you can use a silicon power switch (FPF2004 or FPF2005 recommended), FET, or regulator on your board using any GPIO pin for control (this would be similar to the gyro/9DoF designs-- for more info see the manuals for those). As you noted, Pin7 already provides a power enable on the gyroscope boards when used with various example applications. Finally you can replicate the soft power switch circuit on the shimmer board, using the same part, an LTC2954-2. Tie the PB terminal to RESET, pin 16 and control either a power switch or regulator with the EN# output. -Ben On Thu, May 10, 2012 at 9:43 PM, jianxin Chen <[email protected]> wrote: > Hi all, > > Since in Shimmer2r the BAT(pin 20) in internal expansion connector is > connected to the battery directly, the switch can not control it. Now I have > connected a sensor board to shimmer2r via this BAT (pin 20 in internal > expansion). Is it possible to power off the BAT by some software mode? In > the manual, Pin 7(BSL_tx) in the internal expansion connector and pin 14 > in the external expansion connector are both used for power-enable/control > for internal expansion. Does it mean we can set one of them to zero if we > can detect the switch is being powered off, then the BAT will be zero too?If > it is so, how to detect the powering-off of switch when we turn off the > shimmer2r. > Best regards, > > Jianxin > > _______________________________________________ > Shimmer-users mailing list > [email protected] > https://lists.eecs.harvard.edu/mailman/listinfo/shimmer-users > _______________________________________________ Shimmer-users mailing list [email protected] https://lists.eecs.harvard.edu/mailman/listinfo/shimmer-users
