Wifi / let's have RF stuff powered with high current source all the time because...

Andy Green andy at openmoko.com
Mon Aug 25 22:30:37 CEST 2008


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Somebody in the thread at some point said:
| Am Mo  25. August 2008 schrieb Andy Green:
|> Point taken about the GTA03+ module though -- it should take care of
|> power switching inside the module boundary in a reliable way or the
|> module is broken, so we presumably should be able to just use the module
|> boundary power arrangements.  But still I guess we learn about it during
|> GTA03 EVB.  There was that guy who saw his GTA02 battery consumption was
|> stuck at 500mA on VB when he made no call, I really did not like to hear
|> about it since only the GSM side TX stuff gets that hungry and it seemed
|> there to be doing its own thing.
|
| 100% ACK about scariness of story.
| Though this wasn't exactly for GSM-powerdown state IIRC. So it seems our
| biggest problem these days (for GTA02 GSM at least) is serial
communication
| between CPU and calypso, including not resuming at all, unsolicited
resume
| etc pp.
| A hung call wouldn't seem impossible to me.

Yeah.  The GSM side is so autonomous in power and intelligence it really
can do its own thing.  If the CPU doesn't succeed to take down the call
through broken UART on resume or whatever than this is what you would
see as you say.

It's a pity I didn't ask him to watch consumption when he was quiet and
not handling the phone.  He said that it chewed through some large chunk
of his battery when idle in this state, so the current was real, and a
reboot made that symptom go away.

- -Andy
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org

iEYEARECAAYFAkizFm0ACgkQOjLpvpq7dMoHyQCdGoz/v2lZrSwpeGGcRJIkihOM
6DgAn1OYqLTSEDs0NrtUhhyilWstCVuF
=ljan
-----END PGP SIGNATURE-----



More information about the hardware mailing list