GPS test procedure / test for humans

Andy Green andy at openmoko.com
Wed Jul 30 18:07:41 CEST 2008


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Somebody in the thread at some point said:
| Didn't run all tests The echo 0 >
| /sys/module/glamo_mci/parameters/sd_drive really does wonders on my
| freerunner.
| Without it using a SD card I only once did see one satellite in the
| signal strength list of the AGPS UI. Now i Got 8 satellites -and I no
| more see differences between using the Freerunner with and without an SD
| card.
| I even got a fix when I started the GPS inside my flat (which needed
| about 3 minutes. My commercial GPS never gets a fix when inside).
|
| Since the clock pin of all sd cards I have access to is rather
| high-impedance I personally would estimate the risk of setting the drive
| strength to "0" by default to be rather low.
|
| I am somewhat afraid of soldering wires on pins this small, but if
| really needed I would be willing to oscillograph if my sd card provides
| enough load to degrade the clock signal, though.

The difference between the min and mix drive strengths is quantified in
the Glamo datasheet, it's like 4mA drive capability -> 1mA drive capability.

We did set it to 0 in the end by default and it did not seem to make any
trouble.

Glad you're working OK!

- -Andy


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