Howto Test Your GPS with agpsui

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Line 41: Line 41:
 
== howto ==
 
== howto ==
  
'''1. Assuming you have a fresh-from-the-factory freerunner, first get some
+
# Assuming you have a fresh-from-the-factory freerunner, first get some
 
basic networking configured. this is beyond the scope of this howto.
 
basic networking configured. this is beyond the scope of this howto.
'''2. ssh to the freerunner :
+
# ssh to the freerunner :
[ ssh root@192.168.0.202 ]
+
<blockquote>
'''3a. If you have a working wifi or usb network:  
+
ssh root@192.168.0.202  
[ opkg update ]
+
</blockquote>
 +
# If you have a working wifi or usb network:  
 +
<blockquote>
 +
opkg update  
 +
</blockquote>
 
( Ignore all warnings about missing signature files, the
 
( Ignore all warnings about missing signature files, the
 
openmoko repository haven't got any at the moment.)
 
openmoko repository haven't got any at the moment.)
'''3b. Or if your doing this the basic way, download openmoko-agpsui and
+
## Or if your doing this the basic way, download openmoko-agpsui and
 
then transfer to your freerunner:
 
then transfer to your freerunner:
[ wget
+
<blockquote>
http://buildhost.openmoko.org/daily-feed/armv4t/openmoko-agpsui_*.ipk ]
+
wget http://buildhost.openmoko.org/daily-feed/armv4t/openmoko-agpsui_*.ipk
[ scp openmoko-agpsui_*.ipk
+
scp openmoko-agpsui_*.ipk root@192.168.0.202:/home/root/.  
root@192.168.0.202:/home/root/. ]
+
</blockquote>
 
+
# Install the package openmoko-agpsui:
'''4. Install the package openmoko-agpsui:
+
<blockquote>
[ opkg install openmoko-agpsui ] or
+
opkg install openmoko-agpsui
[ opkg install openmoko-agpsui_*.ipk ]
+
</blockquote>
 
+
or
'''5. After having completed all these steps sucessfully your ready to
+
<blockquote>
 +
opkg install openmoko-agpsui_*.ipk  
 +
</blockquote>
 +
# After having completed all these steps sucessfully your ready to
 
test your freerunner.  
 
test your freerunner.  
 
Charge your battery to full capacity (can't hurt), wait for a clear
 
Charge your battery to full capacity (can't hurt), wait for a clear
Line 68: Line 75:
 
Nice weather is a must have because you don't want your shiny
 
Nice weather is a must have because you don't want your shiny
 
freerunner to get soaked do you?  
 
freerunner to get soaked do you?  
 
+
# Find a place where your freerunner can sit on a stable surface or
'''6. Find a place where your freerunner can sit on a stable surface or
+
 
at least 30 minutes without being molested, fondled or even touched.
 
at least 30 minutes without being molested, fondled or even touched.
 
Leave the freerunner with the screen facing upwards, preferably with
 
Leave the freerunner with the screen facing upwards, preferably with
 
the top of the freerunner facing northish. (Not a requirement, just
 
the top of the freerunner facing northish. (Not a requirement, just
 
trying to be scientific. ;) )
 
trying to be scientific. ;) )
 
+
# on the freerunner Graphical User Interface you should find a program
'''7. on the freerunner Graphical User Interface you should find a program
+
 
called "Openmoko AGPS UI". Run this program.
 
called "Openmoko AGPS UI". Run this program.
 
The program has several interesting features. on the top left side of
 
The program has several interesting features. on the top left side of
 
it's UI you can find the tabs:  
 
it's UI you can find the tabs:  
 
"Run" "SS" "AZ" "plot" "Log"
 
"Run" "SS" "AZ" "plot" "Log"
 
+
:"Run" is the current picture, here you start and stop the GPS
"Run" is the current picture, here you start and stop the GPS
+
:: testing software. Everything with the word "Reset" reset's the
testing software. Everything with the word "Reset" reset's the
+
:: sampling and/or the chipset. "Power on"/"Power off" powers up
sampling and/or the chipset. "Power on"/"Power off" powers up
+
:: (or down) the GPS chipset and starts logging. "One Fix" starts
(or down) the GPS chipset and starts logging. "One Fix" starts
+
:: the logging but powers automatically down after having managed
the logging but powers automatically down after having managed
+
:: to get FFix from a single satelite.
to get FFix from a single satelite.
+
:"SS" gives you signalstrength, calculates average
"SS" gives you signalstrength, calculates average
+
:: signalstrength, identifies the differnt satelites by number and
signalstrength, identifies the differnt satelites by number and
+
:: of course lets you count the number of satelites _IF_ it can
of course lets you count the number of satelites _IF_ it can
+
:: manage to find at least 1 satelite.
manage to find at least 1 satelite.
+
:"AZ" gives you the position of the different satelites _after_ it
"AZ" gives you the position of the different satelites _after_ it
+
:: get's a FFIX. Otherwise a satelite is "defaulted" to being
get's a FFIX. Otherwise a satelite is "defaulted" to being
+
:: somewhere over the northpole. (on a _very_ thight polar orbital
somewhere over the northpole. (on a _very_ thight polar orbital
+
:: indeed. ;) )
indeed. ;) )
+
:"Plot" gives a estimate on where the different satelites say _you_ are,
"Plot" gives a estimate on where the different satelites say _you_ are,
+
:: usually with a margin of +-5 meters. (10 meters in difference.)
usually with a margin of +-5 meters. (10 meters in difference.)
+
:"Log" gives you the NEMA output from the GPS chipset. Interesting for
"Log" gives you the NEMA output from the GPS chipset. Interesting for
+
:: those who can read NEMAish, not so interesting for the rest of
those who can read NEMAish, not so interesting for the rest of
+
:: us.
us.
+
# Now press "Power on" and then "SS", then leave the darn freerunner on
 
+
'''8. Now press "Power on" and then "SS", then leave the darn freerunner on
+
 
the safe and flat surface for _at least 30 minutes without moving or
 
the safe and flat surface for _at least 30 minutes without moving or
 
touching it_. Do not stand over it either, your blocking those precious
 
touching it_. Do not stand over it either, your blocking those precious
Line 107: Line 110:
 
with a wavelength between millimeters and centimeters, now imagine
 
with a wavelength between millimeters and centimeters, now imagine
 
godzilla (you) smashing them. )
 
godzilla (you) smashing them. )
 
+
# After having spent twidling your thumbs or reading a good book for
'''9. After having spent twidling your thumbs or reading a good book for
+
 
30 minutes you get to press the "dBm" button to translate those nasty
 
30 minutes you get to press the "dBm" button to translate those nasty
 
dB.Hz into goodness dBm signals. If you've gotten FFix some of the blue
 
dB.Hz into goodness dBm signals. If you've gotten FFix some of the blue
Line 115: Line 117:
 
signal you got from each satelite and the lower number the average
 
signal you got from each satelite and the lower number the average
 
signalstrength.
 
signalstrength.
 
+
# If you haven't managed to get a FFIX your either doing something
'''10. If you haven't managed to get a FFIX your either doing something
+
 
wrong or your one of those unlucky guys (gals) with a bad solder or
 
wrong or your one of those unlucky guys (gals) with a bad solder or
 
something else that probably requires shipping the phone back to your
 
something else that probably requires shipping the phone back to your
Line 127: Line 128:
 
satelites( +5) and had quite a good reception (maybe > -145 dBm ? )
 
satelites( +5) and had quite a good reception (maybe > -145 dBm ? )
 
the you probably has a working phone.  
 
the you probably has a working phone.  
 
 
Now, I'm not a radio or wireless engineer, so any numbers in dBm should
 
Now, I'm not a radio or wireless engineer, so any numbers in dBm should
 
be taken with a grain of salt. But the main thing is that you followed
 
be taken with a grain of salt. But the main thing is that you followed
 
the basic instruction and did a thorough scientific test! You did
 
the basic instruction and did a thorough scientific test! You did
 
Science!
 
Science!
 
+
# Now report any anomalities to the mailinglist or the guys that told
'''11. Now report any anomalities to the mailinglist or the guys that told
+
 
you to read this howto.
 
you to read this howto.
  

Revision as of 16:27, 14 July 2008

How to test AGPS on the Neo Freerunner

Apparently there are some questions regarding the GPS on some freerunners. There has been anecdotal evidence of time to first fix (TTFix) from between 40 seconds up to 30 minutes. Some owners have reported that they can't achieve TTFix and there are some Freerunners that appear to have bad solder joints between the GPS antenna connector and the Freerunner main PCB. There is a need for a proper method of testing and a howto describing how to test if a Freerunner has a abnormal TTFix or not.

This guide will assume that people has either managed to

  • a. correctly configured usb-networking or
  • b. correctly configured wifi-networking or
  • c. is capable of downloading opkg packages from

buildhost.openmoko.org/daily-feed/ to a computer and then transfer them to the Freerunner with scp.

First of all, what were trying to do is to get a estimate on how well the GPS works. This means that any numbers you aquire is _not_ necessarily comparable with somebody else's. If Alice reports seeing 13 satelites with an signal strength of ~ -140 dBm and got a FFix in 4 minutes then Bob can't assume he has a broken GPS if he saw only 5 satelites at a signal strength of ~ -145 dBm and it tok 45 minutes to get a FFix. If Charlie on the other hand saw only 2 satelites @ ~ -157 dBm and didn't get a FFix after leaving the freerunner on a table for two hours in the midle of nowhere and the freerunner had a clear 360 degrees view then Charlie can safely assume he indeed has a broken GPS.

In fact, these are the number we want you to report: Serial number on your phone. This number is printed on both the black box packaging and under the battery of your freerunner. All serialnumbers are 9 digits and they begin with S/N: 8A86<xxxxx> In adition, we would like you to report then number of satelites your phone managed to detect and a estimate on what the average signal strength in dBm for those satelites. (We don't need to know the average for each satelite, just the average for all satelites.)

howto

  1. Assuming you have a fresh-from-the-factory freerunner, first get some

basic networking configured. this is beyond the scope of this howto.

  1. ssh to the freerunner :
ssh root@192.168.0.202
  1. If you have a working wifi or usb network:
opkg update

( Ignore all warnings about missing signature files, the openmoko repository haven't got any at the moment.)

    1. Or if your doing this the basic way, download openmoko-agpsui and

then transfer to your freerunner:

wget http://buildhost.openmoko.org/daily-feed/armv4t/openmoko-agpsui_*.ipk scp openmoko-agpsui_*.ipk root@192.168.0.202:/home/root/.
  1. Install the package openmoko-agpsui:
opkg install openmoko-agpsui

or

opkg install openmoko-agpsui_*.ipk
  1. After having completed all these steps sucessfully your ready to

test your freerunner. Charge your battery to full capacity (can't hurt), wait for a clear weather and then check out places you can visit. The ideal place is Charlie's midle of nowhere, but the next best thing is a area with clear view of the sky and no towering foliage or buildings nearby. Nice weather is a must have because you don't want your shiny freerunner to get soaked do you?

  1. Find a place where your freerunner can sit on a stable surface or

at least 30 minutes without being molested, fondled or even touched. Leave the freerunner with the screen facing upwards, preferably with the top of the freerunner facing northish. (Not a requirement, just trying to be scientific. ;) )

  1. on the freerunner Graphical User Interface you should find a program

called "Openmoko AGPS UI". Run this program. The program has several interesting features. on the top left side of it's UI you can find the tabs: "Run" "SS" "AZ" "plot" "Log"

"Run" is the current picture, here you start and stop the GPS
testing software. Everything with the word "Reset" reset's the
sampling and/or the chipset. "Power on"/"Power off" powers up
(or down) the GPS chipset and starts logging. "One Fix" starts
the logging but powers automatically down after having managed
to get FFix from a single satelite.
"SS" gives you signalstrength, calculates average
signalstrength, identifies the differnt satelites by number and
of course lets you count the number of satelites _IF_ it can
manage to find at least 1 satelite.
"AZ" gives you the position of the different satelites _after_ it
get's a FFIX. Otherwise a satelite is "defaulted" to being
somewhere over the northpole. (on a _very_ thight polar orbital
indeed. ;) )
"Plot" gives a estimate on where the different satelites say _you_ are,
usually with a margin of +-5 meters. (10 meters in difference.)
"Log" gives you the NEMA output from the GPS chipset. Interesting for
those who can read NEMAish, not so interesting for the rest of
us.
  1. Now press "Power on" and then "SS", then leave the darn freerunner on

the safe and flat surface for _at least 30 minutes without moving or touching it_. Do not stand over it either, your blocking those precious satelite signals! ( GPS runs at ~ 1,2-1,5 Ghz, this is a weak signal with a wavelength between millimeters and centimeters, now imagine godzilla (you) smashing them. )

  1. After having spent twidling your thumbs or reading a good book for

30 minutes you get to press the "dBm" button to translate those nasty dB.Hz into goodness dBm signals. If you've gotten FFix some of the blue blue bars has a nice black thing on the bottom. And on top of screen above each bar there are two numbers, the top denoting the maximum signal you got from each satelite and the lower number the average signalstrength.

  1. If you haven't managed to get a FFIX your either doing something

wrong or your one of those unlucky guys (gals) with a bad solder or something else that probably requires shipping the phone back to your supplier/openmoko. If you got only 3-4 satelites and had a lousy reception (say -150 to -160 dBm) you /might/ have a faulty freerunner but you should try again somewhere else at another time of the day just to make sure. If you had a lousy reception but did get a FFix, try again somewhere else to se if you can improve your record. If you on the other hand found several satelites( +5) and had quite a good reception (maybe > -145 dBm ? ) the you probably has a working phone. Now, I'm not a radio or wireless engineer, so any numbers in dBm should be taken with a grain of salt. But the main thing is that you followed the basic instruction and did a thorough scientific test! You did Science!

  1. Now report any anomalities to the mailinglist or the guys that told

you to read this howto.

Recommended Reading

http://wiki.openmoko.org/wiki/Getting_Started_with_your_Neo_FreeRunner http://wiki.openmoko.org/wiki/FreeRunner_GPS_antenna_repair_SOP http://wiki.openmoko.org/wiki/USB_Networking http://en.wikipedia.org/wiki/Global_Positioning_System

Personal tools

How to test AGPS on the Neo Freerunner

Apparently there are some questions regarding the GPS on some freerunners. There has been anecdotal evidence of time to first fix (TTFix) from between 40 seconds up to 30 minutes. Some owners have reported that they can't achieve TTFix and there are some Freerunners that appear to have bad solder joints between the GPS antenna connector and the Freerunner main PCB. There is a need for a proper method of testing and a howto describing how to test if a Freerunner has a abnormal TTFix or not.

This guide will assume that people has either managed to

  • a. correctly configured usb-networking or
  • b. correctly configured wifi-networking or
  • c. is capable of downloading opkg packages from

buildhost.openmoko.org/daily-feed/ to a computer and then transfer them to the Freerunner with scp.

First of all, what were trying to do is to get a estimate on how well the GPS works. This means that any numbers you aquire is _not_ necessarily comparable with somebody else's. If Alice reports seeing 13 satelites with an signal strength of ~ -140 dBm and got a FFix in 4 minutes then Bob can't assume he has a broken GPS if he saw only 5 satelites at a signal strength of ~ -145 dBm and it tok 45 minutes to get a FFix. If Charlie on the other hand saw only 2 satelites @ ~ -157 dBm and didn't get a FFix after leaving the freerunner on a table for two hours in the midle of nowhere and the freerunner had a clear 360 degrees view then Charlie can safely assume he indeed has a broken GPS.

In fact, these are the number we want you to report: Serial number on your phone. This number is printed on both the black box packaging and under the battery of your freerunner. All serialnumbers are 9 digits and they begin with S/N: 8A86<xxxxx> In adition, we would like you to report then number of satelites your phone managed to detect and a estimate on what the average signal strength in dBm for those satelites. (We don't need to know the average for each satelite, just the average for all satelites.)

howto

1. Assuming you have a fresh-from-the-factory freerunner, first get some basic networking configured. this is beyond the scope of this howto. 2. ssh to the freerunner : [ ssh root@192.168.0.202 ] 3a. If you have a working wifi or usb network: [ opkg update ] ( Ignore all warnings about missing signature files, the openmoko repository haven't got any at the moment.) 3b. Or if your doing this the basic way, download openmoko-agpsui and then transfer to your freerunner: [ wget http://buildhost.openmoko.org/daily-feed/armv4t/openmoko-agpsui_*.ipk ] [ scp openmoko-agpsui_*.ipk root@192.168.0.202:/home/root/. ]

4. Install the package openmoko-agpsui: [ opkg install openmoko-agpsui ] or [ opkg install openmoko-agpsui_*.ipk ]

5. After having completed all these steps sucessfully your ready to test your freerunner. Charge your battery to full capacity (can't hurt), wait for a clear weather and then check out places you can visit. The ideal place is Charlie's midle of nowhere, but the next best thing is a area with clear view of the sky and no towering foliage or buildings nearby. Nice weather is a must have because you don't want your shiny freerunner to get soaked do you?

6. Find a place where your freerunner can sit on a stable surface or at least 30 minutes without being molested, fondled or even touched. Leave the freerunner with the screen facing upwards, preferably with the top of the freerunner facing northish. (Not a requirement, just trying to be scientific. ;) )

7. on the freerunner Graphical User Interface you should find a program called "Openmoko AGPS UI". Run this program. The program has several interesting features. on the top left side of it's UI you can find the tabs: "Run" "SS" "AZ" "plot" "Log"

"Run" is the current picture, here you start and stop the GPS testing software. Everything with the word "Reset" reset's the sampling and/or the chipset. "Power on"/"Power off" powers up (or down) the GPS chipset and starts logging. "One Fix" starts the logging but powers automatically down after having managed to get FFix from a single satelite. "SS" gives you signalstrength, calculates average signalstrength, identifies the differnt satelites by number and of course lets you count the number of satelites _IF_ it can manage to find at least 1 satelite. "AZ" gives you the position of the different satelites _after_ it get's a FFIX. Otherwise a satelite is "defaulted" to being somewhere over the northpole. (on a _very_ thight polar orbital indeed. ;) ) "Plot" gives a estimate on where the different satelites say _you_ are, usually with a margin of +-5 meters. (10 meters in difference.) "Log" gives you the NEMA output from the GPS chipset. Interesting for those who can read NEMAish, not so interesting for the rest of us.

8. Now press "Power on" and then "SS", then leave the darn freerunner on the safe and flat surface for _at least 30 minutes without moving or touching it_. Do not stand over it either, your blocking those precious satelite signals! ( GPS runs at ~ 1,2-1,5 Ghz, this is a weak signal with a wavelength between millimeters and centimeters, now imagine godzilla (you) smashing them. )

9. After having spent twidling your thumbs or reading a good book for 30 minutes you get to press the "dBm" button to translate those nasty dB.Hz into goodness dBm signals. If you've gotten FFix some of the blue blue bars has a nice black thing on the bottom. And on top of screen above each bar there are two numbers, the top denoting the maximum signal you got from each satelite and the lower number the average signalstrength.

10. If you haven't managed to get a FFIX your either doing something wrong or your one of those unlucky guys (gals) with a bad solder or something else that probably requires shipping the phone back to your supplier/openmoko. If you got only 3-4 satelites and had a lousy reception (say -150 to -160 dBm) you /might/ have a faulty freerunner but you should try again somewhere else at another time of the day just to make sure. If you had a lousy reception but did get a FFix, try again somewhere else to se if you can improve your record. If you on the other hand found several satelites( +5) and had quite a good reception (maybe > -145 dBm ? ) the you probably has a working phone.

Now, I'm not a radio or wireless engineer, so any numbers in dBm should be taken with a grain of salt. But the main thing is that you followed the basic instruction and did a thorough scientific test! You did Science!

11. Now report any anomalities to the mailinglist or the guys that told you to read this howto.

Recommended Reading

http://wiki.openmoko.org/wiki/Getting_Started_with_your_Neo_FreeRunner http://wiki.openmoko.org/wiki/FreeRunner_GPS_antenna_repair_SOP http://wiki.openmoko.org/wiki/USB_Networking http://en.wikipedia.org/wiki/Global_Positioning_System