Bug #1024 (oscillating re-camping), the story goes on...

Dieter Spaar spaar at openmoko.org
Mon Apr 6 09:57:17 CEST 2009


Hello,

maybe interesting: The current the GSM modem draws while in
"Deep Sleep" is ca. 120 uA, if it is in "Big Sleep", the current is
ca. 5.5 mA. This does not say much how long the battery will
last if "Deep Sleep" or "Big Sleep" is used. It depends on several
other things like the power consumption of the rest of the system
or how long the GSM modem can actually sleep (cell parameter,
could be ca. 0.5 to 2.1 seconds).

BTW, I found a different register setting which seem to control
the current of the 32 kHz oscillator. However I don't have the
documentation for our variant of the Calypso chip. So I can
only guess or try the possible values of this register. I can
measure a difference of about 10 uA in "Deep Sleep" mode
between using what  I think means the lowest and highest
current.

Best regards,
  Dieter



More information about the hardware mailing list