747A+ unable to download tracks.

AdaIsDead's picture


I just got a 747A+ logger and while i can get a location fine downloading the logs dosn't work

Looking at the debug logs it seems to just loop forever with PMTK182 commands.

I've attached the logs.

The Phototagger software that came with the gps dosn't work either, and neither does gpsbabel.

Let me know if you want more serial port captures, i'm using sysinternals portmon.

This is all with USB.

mdeweerd's picture

Hi 1) I would need a


1) I would need a 'connection debug' log. You can activate this in the menu and find the gpsrawdebug.txt .
2) It might be that the amount of data coming back is not handled correctly on your computer and that some of it gets lost. In the 'Advanced Device Settings', you may want to set the chunk size to a small value (2048 for instance) and chunk requests to 0. If that works, you can increase chunk requests and/or the chunk size untill it no longer works or untill it is fairly fast for you.

Please compress the log before uploading it ;-).

AdaIsDead's picture

Hi Here are logs with both


Here are logs with both the default chunk size and the smaller one.

It didn't work in either case.

the file extention is .txt cos it wouldn't let me upload .zip files, so you'll have to rename it.

mdeweerd's picture

I had a look at the logs (and

I had a look at the logs (and now going to bed). What I see does confirm some kind of communication error - the reason for it is pretty strange. NMEA position sentences just get broken abruptly and for the data, the initial part of the sentence is missing at least.

While I still suspect a driver issue, it might be best to user a serial port monitor to get the data. There are some of those that you can get on the web - one of them is 'hdd serial port monitor'. Can you capture a log in there and in BT747 too for comparison.

You can also try making the chunk size even smaller. Obviously 2048 may still be 'too big' - try a 'very small' number: 100. That will make the responses fit in 255 bytes.

It could be that the port went into PIO mode in stead of DMA mode on your PC - but that is 'advanced' stuff to configure.

AdaIsDead's picture

I booted into linux and tried

I booted into linux and tried it under that and ended up running around several different issues mostly not related to bt747.

firstly the linux kernel i was using needs a quirk entry for the gps applied before it would recognise it properly:


Once that was done i got a /dev/ttyACM0, however BT747 didn't want to open it.

However i got correct looking NEMA strings using cat /dev/ttyACM0 so i tried gpsbabel, and sure enough gpsbabel -D 2 -t -i mtk -f /dev/ttyACM0 -o gpx -F fish.gpx produced a .gpx file with a track that looked sane.


Win2k has some driver issue, i'll try the smaller chunk size in a moment

BT747 needs to allow /dev/ttyACM0 as a valid serial port under linux.

My gps isn't broken :)

AdaIsDead's picture

With a chunk size of 100 it's

With a chunk size of 100 it's downloading under win2k now.

very slowly tho :)

I'll try a larger chunk size when it's done.

I also disabled the FIFO stuff for this serial port, was the only thing i could change in the control panel.

I'll also try it with the FIFO back on again.

mdeweerd's picture

At least you get to download

At least you get to download something now ;-).

Regarding '/dev/ACM0' not being recognized: what version of BT747 are you using and where did you get it? That will help me fix the distribution that is still not "fixed" (I guess 1.68.25 from sf.net).

The fifo should be on in principle.

AdaIsDead's picture

download finished and the

download finished and the .gpx looks ok in merkaartor.

Trying again with the FIFO on and chunk size = 128, chunk requests = 3.

AdaIsDead's picture

I'm using V2.X.1516 from

I'm using V2.X.1516 from here.

I've also tried the 'install the latest version' from there with the same result.

mdeweerd's picture

Ok, can you try BT747 Latest

Ok, can you try BT747 Latest using RxTx 2.2pre2 (RxTx dev version) for Windows 32 & 64 bit, MacOSX, Linux..
I'll check the setup for the link you provided regarding /dev/ttyACM0, but the link I provide here refers to a more recent developement version of the RXTX driver. I think it is worthwhile to check its impact.

AdaIsDead's picture

Tried that and it dosn't

Tried that and it dosn't work. After a bit of fiddling around i've found the java console and got this: Reading certificates from 13574 http://soft.bt747.org/Latest/libBT747.jar | /home/jasper/.java/deployment/cache/6.0/57/535334b9-5ef3ee4a.idx Reading certificates from 3604 http://soft.bt747.org/swing-layout-1.0.3.jar | /home/jasper/.java/deployment/cache/6.0/3/7bea7783-4255d234.idx Reading certificates from 29708 http://soft.bt747.org/swingx-ws.jar | /home/jasper/.java/deployment/cache/6.0/53/1ebc3a75-238f9449.idx Reading certificates from 103502 http://soft.bt747.org/swingx.jar | /home/jasper/.java/deployment/cache/6.0/40/1fef2da8-143f69dd.idx Reading certificates from 9582 http://soft.bt747.org/jcalendar-1.3.2.jar | /home/jasper/.java/deployment/cache/6.0/23/2baf7017-440b12a4.idx Adding bt747.j2se_view.J2SEAppModel@b60b93 2360 - Data request of 0 skipped 3161 - BT747 2.X.1516 Build:BT747_mdeweerd.1516.20090912185300787 3195 - Linux 3197 - i386 3200 - 2.6.28-15-generic 3204 - 1.6.0_16 3205 - Fail com.sun.java.swing.plaf.windows.WindowsLookAndFeel Fail com.sun.java.swing.plaf.windows.WindowsClassicLookAndFeel Success com.sun.java.swing.plaf.gtk.GTKLookAndFeel javax.swing.plaf.metal.MetalLookAndFeel com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel com.sun.java.swing.plaf.motif.MotifLookAndFeel com.sun.java.swing.plaf.gtk.GTKLookAndFeel Reading certificates from 13574 http://soft.bt747.org/Latest/libBT747.jar | /home/jasper/.java/deployment/cache/6.0/57/535334b9-5ef3ee4a.idx Opened file /home/jasper/gpsRawDebug.txt in mode 4 rw Opened file /home/jasper/gpsRawDebug.txt in mode 3 rw Reading certificates from 4920 http://soft.bt747.org/RXTXcomm2_2p2.jar | /home/jasper/.java/deployment/cache/6.0/11/10d3184b-7e4f37c8.idx java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path thrown while loading gnu.io.RXTXCommDriver Exception in thread "Thread-11" java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1709) at java.lang.Runtime.loadLibrary0(Runtime.java:823) at java.lang.System.loadLibrary(System.java:1028) at gnu.io.CommPortIdentifier.(CommPortIdentifier.java:123) at bt747.j2se_view.BT747Main.access$3200(Unknown Source) at bt747.j2se_view.BT747Main$36.run(Unknown Source) 40987 - Classgps.connection.GPSRxTxPort Info: trying to open '/dev/ttyACM0' Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: Could not initialize class gnu.io.CommPortIdentifier at gps.connection.GPSRxTxPort.openPort(Unknown Source) at gps.connection.GPSrxtx.myOpenPort(Unknown Source) at gps.connection.GPSrxtx.setFreeTextPortAndOpen(Unknown Source) at bt747.model.Controller.openFreeTextPort(Unknown Source) at bt747.j2se_view.BT747Main.access$300(Unknown Source) at bt747.j2se_view.BT747Main$6.actionPerformed(Unknown Source) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387) at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236) at java.awt.Component.processMouseEvent(Component.java:6263) at javax.swing.JComponent.processMouseEvent(JComponent.java:3267) at java.awt.Component.processEvent(Component.java:6028) at java.awt.Container.processEvent(Container.java:2041) at java.awt.Component.dispatchEventImpl(Component.java:4630) at java.awt.Container.dispatchEventImpl(Container.java:2099) at java.awt.Component.dispatchEvent(Component.java:4460) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4574) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168) at java.awt.Container.dispatchEventImpl(Container.java:2085) at java.awt.Window.dispatchEventImpl(Window.java:2475) at java.awt.Component.dispatchEvent(Component.java:4460) at java.awt.EventQueue.dispatchEvent(EventQueue.java:599) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161) at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

mdeweerd's picture

I'll have a look to see if I

I'll have a look to see if I can fix that - possibly your system is 'not in the list'.

mdeweerd's picture

You can try it again - I had

You can try it again - I had it setup for 64 bit systems only, but I added 32bit now.

The latest development

The latest development version that you posted in this thread works for me on Linux (32bit.)

Please could you tell me how to run this version on my own machine. I keep having to click the link on this page to run it.


mdeweerd's picture

Hi I made an update for the

I made an update for the other versions too (web start) and you should be able to use one of the install links.

Normally the stable version should have the same change, but as far as I understood, there was a problem with that. I do not think the problem is this serial driver - webstart usually runs faster for the end user.

We can try to fix the issue for the zip file (from sourceforge).