On Sun, Sep 06, 2009 at 03:47:31AM +0100, Dave Ball wrote: > I've had a first stab at schematics for the Telit modem. Comments, > feedback, abuse all welcome :-)
The GE865 Hardware User Guide recommends that the antenna trace be shielded on all sides by ground traces (page 26). Looking at "3.1.1 BGA Balls Layout", I think we should tie GPIO_07 to ground, thereby completing the shield of ground balls around the antenna ball. Admittedly, doing so is in conflict with the statement on page 9: "If not used, almost all pins should be left disconnected." (listing some exceptions, which doesn't include GPIO_07.) GPIO_04/TX_DISAB can be used to disable the transmitter (11.4). A possible use for it would be to detect surrounding cells for use with the cellhunter/openbmap database without spending battery power or privacy on transmitting your own position[1]. This signal needs no fancy level translation, I think, just a simple voltage divider. We have GPB5 available and no special function to use it for, I think. What are the chances I could persuade you to move the MODEM_SERVICE and MODEM_SLEEP signals from GPJ2/GPJ3 (cpu.sch) to GPC8/GPC9 (lcm.sch) instead? Just two signals less on the camera interface. [1] After which you send a clear text HTTP request to a map tile server for retrieval of the map tiles of the area you're in. :-( But we'll get there eventually. -- Rask Ingemann Lambertsen Danish law requires addresses in e-mail to be logged and stored for a year _______________________________________________ gta02-core mailing list [email protected] https://lists.openmoko.org/mailman/listinfo/gta02-core
