GTA04 Block V4 / risk and possibility

Karsten Ensinger karsten.at.openmoko at onlinehome.de
Fri May 2 13:26:54 CEST 2008


Please apologise my lack of knowledge in this part of hardware
design, but can someone explain, how the additional MPU could
help to "solve" a problem I think the current design may have?

The GTA0?s have a GPS chip which will provide NMEA-data via
an UART interface. One of the (imho) most important advanced
features of the GTA?s is the possibility to provide location
based information.
If I want to use this feature all the time, the GPS chip will
deliver data packets continuously and therefore one has to take
care continuously.
At the moment (looking at the PDF diagram) for the most simple
usage (record the NMEA-data) the regular CPU has to be used
continuously, which will degrade battery life significantly.
How will the MPU help in this case? Can the MPU used as a kind
of "data buffer" to reduce the amount of CPU wakeups?
I do not want to sound rude, but just a "long-life" telephone
seems not to be the killer feature the world waits for. If you
combine this "long-life" telephone with a "long-life" location
aware PDA, you will meet more needs.
But maybe my intentions of usage of the GTA?s is different to
that of all others? The most valuable scenarios for me are to
record my trips into the nature (hiking and biking) and to get
pointed to interesting sites nearby.
I don't know how much current the GPS chip consumes and if it
is possible at all, regarding battery capacity, to run this
beast continuously, but it would be an outstanding feature if
one could record the GPS data for a whole day.

Regrads
Karsten




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