(TECH) GPS xadow board battery backup

End-Of-Life Products & Services RePhone
#1

The Quectel L70 GPS chip on the xadow board has a pin, V_BCKUP, which is meant to be supplied with a battery to allow the location data to be preserved even during power loss to Vcc (hardware reference diagram mentions a particular coin cell battery).

The schematic file URL

seeedstudio.com/wiki/images/ … GPS_v2.rar

referenced in the wiki page

seeedstudio.com/depot/Xadow- … -2557.html

takes me to a rar file which is not valid. I cannot determine if the 3v3 pad on the bottom of the board is wired to that pin or not. Does somebody here have a link to a valid schematic file, or a definitive answer about that pin?

Thanks

#2

The rar file is perfectly valid for me, and it shows that the V_BCKP is totally there, R5 0 Ohm resistor connects it to 3.3V - that means you can desolder it to add a backup battery, that is not connected to the main 3.3V (therefore won’t supply anything but the GPS)