[Gen9, Gen10 General] scholbert:
It's little bit mystic...

Hey guys,

last week i also thought about open up a thread related to GPS issues on the Gen9 series, because i had some trouble to get a fix as well.

I'm using an Archos 80 G9.

The same with my device at first.

I used the rooted ICS 4.0.5 and GPS Status from the market and started some experiments.

There'd been no response from the GPS part at all.

After some time i used a serial port api tool to directly connect to ttyO0.

Though the GPS part uses some hex protocol i had been able to get a response from the chip, but it was not human readable.

So this way i made sure there's no hardware damage on my UART interface or GPS chipset.

Afterwards i did some hard resets and checked settings of the UART by typing:

stty -F /dev/ttyO0

I started to run GPS Status again and also deleted my AGPS data by using the tools menu. Then i changed GPS Status setup to stay active and prevent device from sleep.

I took a while, but then the first satellite came in sight, still no fix.

Next day i did the same after some time more and more satellite where seen, but still no fix.

I restarted my device again to boot stock firmware.

Same again... more and more satellites became visible... but then... suddenly a fix. In fact it took very very long and i'm not very satisfied with the situation.

After i re-booted to rooted firmware again i was able to get a fix here as well.

The signal reception is still far from being nice though.

Try to get a fix with stock firmware first, then reboot and check again with rooted firmware.

Should be no problem with this setup.

AFAIK, these three settings address different services.

GPS should be set of course.

Nice thread, but people start to mix things up at some point.

Though the GPS and location service on Android OS is quite mystic, i'll try to concentrate on some facts.

Hardware:

- NL5550 chipset used on Archos Gen9 is up to date and not that bad

(merged into WL1283 chipset, see http://www.murata-ws.com/com7.htm)

- Due to hugh shielding areas, GPS reception is not the best with tablets (if compared to handsets).

- GPS antenna and position of the antenna seems to be problematic

Software:

- Firmware setup changed form HC to ICS

- size of the patch file for the chip had grown in ICS

(mabye they wanted to make thinks better, but they got worse)

So what could be done...

Hardware:

- I started searching for a better antenna to be placed in the housing

(e.g. helical/helix antenna)

- Place a HF-connector on the mainboard to use an external antenna

Software:

- Extract the firmware files from HC and try this setup for ICS

- try to find other devices based on the navilink chipset and compare their firmware setup

Basically GPS works on ICS and things in fact are not related to ICS itself.

Some firmware tweaks might be the cause of these issues.

The basic construcion of the hardware could have some side-effects on this as well.

Some people seem to have no trouble at all, so at least GPS reception is of course little bit depended on the weather and the area you live in.

I may post the HC firmware files here, if you like to try the HC setup on your device.

Cheers,

scholbert