I'm looking to find a compact power solution for the mbed and several other devices. The problem is with my gps as it needs 5v and 45mA. When I power over the Vin pin with a 7.4v 2cell LiPo the Vu pin only has about 1.2V... What would cause this? Has anyone found any good compact battery solutions for powering the mbed and 5V devices?

I think the mbed only has 3.3V regulation. The Vu pin is only available when the mbed is powered over USB. It just exposes the 5V power from the USB bus. You would need a separate 5V regulator to power the GPS from your LiPo battery.

Or use DC Step down converter to 5V

you just need a LOW DROPOUT VOLTAGE REGULATOR

Driven directly from your Li-Po Cell.

78L05 in a to92 package might just get you enough or search for the same type (but 5V) as the MBED.

Althoug Farnell & RS have thousands, dont forget 100nf & 10uf on both input & most important O/P of the regulator.

If you get one that can handel 150mA, then you could power MBED from 5V, which will directly allow USB memory stick etc..

Hope this is sensible/usefull

Ceri