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Paul Kocialkowski, 02/17/2012 10:55 AM



The non-free files holding the GPS infos/code are the following:



Apparently, the protocol that is used by the chip to provide the GPS infos is MEIF. The GPSD component is in charge of translating that to standard NMEA that is sent to the lib via the /dev/socket/gps Unix socket, created by GPSD.


We have written code to read data from the correct serial interface:

It currently doesn't work: it fails to somehow boot the chip. Though, it works after starting gpsd once and stopping it. It must be doing some kind of magic code to start the chip.

Related gps.xml parameters

We have tried to change some parameters in gps.xml to see how it behaves:

Parameter Original Changed to Result
acPortName /dev/s3c2410_serial1 /dev/s3c2410_serial42 The chip wasn't "booted"
gpioNStdbyPath /sys/class/sec/gps/GPS_PWR_EN/value /sys/class/sec/gps/GPS_PWR_EN/value2 The chip was booted
gpioNResetPath /sys/class/sec/gps/GPS_nRST/value /sys/class/sec/gps/GPS_nRST/value2 The chip was booted

After all, it seems that when the gpsd binary is running without the library, the chip isn't started (our test utility doesn't work) whereas when the library is running and connects to the socket when it is created by starting gpsd, the chip is booted. The init code is probably in then.

Updated by Paul Kocialkowski almost 11 years ago · 3 revisions

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