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T O P I C    R E V I E W
gpspassion Posted - 11 mars 2007 : 00:00:39
UPDATED MARCH 2011 : MTK chipset MT3328 (host-based version o MT3329à used on Garmin nuvi 3790.
UPDATED SEPTEMBER 2008 : MTK chipset v2 (MTK 3329) is available on the Qstarz Nano Q1300 datalogger, see details below.
The MTK chipset took the GPS world by surprise in the fall of 2006 with the arrival of Transystem's iBlue 737 when many of us had been anticipating the NemeriX NJ2020/Nx3 based iBlue 727 that remains unavailable to this day.

A quick summary for the MTK chipset would be "powerful and lean", powerful because rated and perceived sensitiviy is on par with SiRFstarIII and lean because the battery life of MTK based receivers was 3x that of SiRFstarIII receivers. However the SiRFstarIII-LT chipset has become available (on the Garmin GPS10x) and battery life is now equivalent.

Compared to the SiRFstarIII receiver it provides more accurate tracks when driving, with better resistance to multipath problems (bounced signals in urban environments), but it appears to have been tuned for driving and not pedestrian use where it has issuss getting back on track in some situations. (UPDATED 200707 : low speed tracking, not to be confused with SiRF's Static Navigation setting, fixed starting with FW1.92, now performs on par with SiRFstarIII and Skytraq, see this comparison). On average it also has a longer time to first fix in the morning on average.

- Qstarz BT-Q1300 logger with AXN_0.3-B_1.3_C01, see more

In order of appearance :
- iBlue 737/Qstarz 810
- Qstarz 815 Solar GPS
- Qstarz 818
- iBlue 747/757 Bluetooth loggers
- Holux M-1000
- Qstarz BT-Q1000 logger
- Garmin nüvi 2x0 AIO - more
- Garmin eTrex Vista HCx - more
- Qstarz Q1200 logger with v2.0 - more
- Qstarz BT-Q1000P logger with Bcore 1.1, see more
- Semsons M7 BT GPS with Bcore 1.1, see more

Please use the thread dedicated to each of these receivers to discuss their specific features.

- Q1300 (08/2008) : AXN_0.3-B_1.3_C01
- 737 (sample - 09/2006) : M-core_1.5,0000 - 1.902_23_1102_0000,0609_m0247,0001
- 737 (shipping) : Mcore_1.62,0001 - 1.902 28 1102 0001,0609
- 737 (shipping-c300k) : M-core_1.8,0001 - 1.902_0__1102_0001,0609_m0279,0001
- Qstarz 810 : Mcore_1.62,0001 - 1.902_28_1102_0001,0609_mA254,0001
- Qstarz 815 : M-core_1.51,0002 - 1.902_23_1102_0002,0609_m0247,0001
- 747 : M-core_1.8 0011 - 1.902_40_LOG1.3_1102_0017,0609_m0279,0001
- 757/ZI v1 : M-core_1.8 1388 - 1.902_40_LOG1.3_1102_5000,0609_m0279,0001
- 757/ZI v2 (>06/2007) : M-core_1.94,5202
- Polaris iBT-GPS : M-core_1.8,0001 - 1.902_40_1102_0001,0609_m0279,001
- USB GPS : 1.902_34A_1102_0006, 0609_m0269 Mcore_1.72
- Holux M1000 : Mcore_1.8,0001 - 1.902_38_B09_1100_0001,0609_m0297,0001
- Qstarz BT-Q1000 : Mcore 1.94001
- Qstarz BT-Q1200 : M-core_2.0,8300,QST1000,*64, see see review
- Gisteq Phototrackr Lite : M-core 2.0, see topic
- Qstarz BT-Q1000P : Bcore 1.1, see topic

- MTK Proprietary commands : link
- MTK chipset operating at 5hz : link
- Logging > 1Hz : link

  • BT747 Configuration , Log downloading, Google Maps creator - BT747
  • PC Configuration utility on the TS site - GPSview 1.0.3
  • PC Configuration utility on the Sparkfun site - MiniGPS 1.32
  • Activating SBAS from a PC or PPC with MTKTweak, see below
  • Sending commands over Bluetooth, seebelow
150   L A T E S T    R E P L I E S    (Newest First)
Mario. Posted - 23 janv. 2013 : 19:19:59
I hope this photo site is OK, any complaints - just send me an e-mail





Mario. Posted - 23 janv. 2013 : 19:08:47
Hello everyone (after a loong while).
Many people asked which receiver supports commands via Bluetooth.
My Holux M-1000C supports not only commands via bluetooth, I can download and set reports both via USB and Bluetooth at the same time.

Also, I am able to set 10 Hz reporting and it does exactly that. One can run on USB port, the other can run at Bluetooth port, independently.

What more, I am able to use 10-Hz recording mode.

But recently I updated firmware with some weird one and I am unable to use MtkDlut, my favourite download tool since I got the receiver.
I have to use what Mario Deveerd will offer you ;-)

I am now interested in using the precision time synchronisation and voila! Here on the PCB I can see two serial transmit and receive channels! Viva la revolucion! Wait... am I hallucinating again? Nevermind, here are the excellent photos! [[in a second]]

MTK3329, the most sensitive receiver of all so far. (The better the Signal/Noise ratio, the higher your accuracy is!)
emusic Posted - 21 mars 2012 : 08:50:05
Originally posted by joegps

after some tests with no success and the email-reply from silabs (no USB-driver for wm2003/arm availible) i stop further research.

I have LOOX 720 (Pocket PC 2003) and USB GPS dongle based on CP2104. To use them together, I have adapted SiLabs CE 5.0 VCP driver to CE 4.2, it runs on WM2003.

The driver is available here.

I understand that five years passed but some people still use WM 2003 PDAs like Loox.
mdeweerd Posted - 30 juin 2011 : 10:33:25

Hi folks,
Better late than never: I have identified the chip.
If anyone still cares, it's an AUR9801D manufactured by Auramicro Corp.
The corresponding datasheet can be found at


It was not a question of mine but interesting to know.
urbano Posted - 29 juin 2011 : 22:27:15
The Ic has the following inscriptions on it:


Does anyone know what this chip is? or even its commercial reference? or its manufacturer?

Any help, would be great appreciated.

Kind Regards

Hi folks,
Better late than never: I have identified the chip.
If anyone still cares, it's an AUR9801D manufactured by Auramicro Corp.
The corresponding datasheet can be found at

Hurston Posted - 21 mars 2011 : 10:44:57
I don't think it does. I was going to get one of those in the hope that it would support NMEA commands over bluetooth.
discord Posted - 21 mars 2011 : 06:19:16
What about the Holux M-1200E, I flipped through their manual and didnt notice anything about AGPS. Can this device support AGPS?
mdeweerd Posted - 20 mars 2011 : 09:15:31
Only Mediatek can confirm if all their MTKII devices support AGPS or not.
Another condition is that the protocol support AGPS upload. Transystem devices support it, but Holux has their own protocol. If AGPS upload is not supported in the device protocol, there is no support.
Some manufacturer may have chosen not to mention AGPS because they do not support it in their software.

BT747 can upload AGPS data to the device using the standard 'Transystem' protocol.

BT747 gets the data from Transystem and an authorisation was obtained to do so.
discord Posted - 20 mars 2011 : 03:57:20
Are all MTK v2 (MTK 3329) devices AGPS compatible? I noticed some MTK v2 (MTK 3329) based dataloggers have no mention of AGPS in their product manuals. Do 3rd party tools such as bt747 allow MTK v2 (MTK 3329) based dataloggers to upload AGPS data? Where do you aquire AGPS satellite data. I'm new to the GPS devlopments of the last 10 years.
gpspassion Posted - 12 mars 2011 : 10:07:32
The so-called "Static navigation" problem was fixed with the MTK v2 chipset so that's taken care of. Not sure about commands over Bluetooth, you could check what they have at and ask them if they can try that for you.
Hurston Posted - 12 mars 2011 : 09:22:21
Assuming that I'm not going to get the 818XT to work, is there a MTK2 bluetooth receiver that can receiver NMEA commands over bluetooth and not just USB, and also doesn't suffer from the static navigation bug mentioned elsewhere in this thread?
gpspassion Posted - 05 mars 2011 : 00:05:27
Sorry can't guess where it is either.

In other news, popej found that the Garmin nuvi 3790T uses the MT3328 MTK chipset : - the host-based version of MTK v2. First post updated.
Hurston Posted - 03 mars 2011 : 13:45:53
I've recently bought a QStarz 818XT, and like so many others in this thread, I've come across the problem that I can't send NMEA commands to the thing over bluetooth, only USB. I'd like to control it from the android app that I'm writing, so it would be nice to get this working. I've read about the resistor hack, and that is all well and good, but I'm not sure where the resistor is supposed to go on this particular board. I've taken a photo of both sides of the board, in case anyone can help me out here.

Doomsday Posted - 16 juin 2010 : 14:09:01

how to put 5Hz from Holux M-1000 ?

Thx !
mdeweerd Posted - 24 mars 2010 : 00:19:42
I think that the resistors next to that component are a solution for a connection.
There are relatively cheap oscilloscopes - I use it rarely, but it is usefull on these rare occasions to see what happens.
ciroiodice Posted - 24 mars 2010 : 00:06:36
Eheheh... an oscilloscope :D I'd like to have one. I remember there were projects of really simple (but better than nothing) oscilloscopes for the PC, using the microphone input line. I should check if i find one. About the CP210x, instead, I had already downloaded its datasheet, but it has too small connections. I can't really reach that soldering precision that's why I was looking for other ways to get my serial NMEA output from the MTK.
mdeweerd Posted - 23 mars 2010 : 18:21:38
I use an oscilloscope for that ;-).
The voltage range is in the area of the battery which is 3.7V nominal - so 0V - 3V is probably ok - your pic probably has similar levels.
Have a look at the specs of the CP210x, measure the voltage on that component and you'll know what electrical specifications you need to respect.
You could also only partially disconnect the CP210x and keep that device as a 'listener' (disconnecting its TX line). That way you can hook up the device to a computer, connect to the serial link and observe whatever the CP210x sees on its RX.
ciroiodice Posted - 23 mars 2010 : 18:07:07
Hi Mario,
This is my 747:

My doubt is, how could I check that I'm actually getting serial data over those GRX/GTX holes? Any idea about possibles voltage ranges and other electrical specs?
mdeweerd Posted - 22 mars 2010 : 20:55:23

With the older iblue 747 devices this is surely possible. The board holds a CP210x (I think x=2) device to do the serial to USB bridge.
Bluetooth is connected to the serial link through some resistances.
What you could do is solder of the USB device. I believe there are some holes (vias) the have the RX and TX data that you can easily put some wires in and have a serial connection out directly.
ciroiodice Posted - 22 mars 2010 : 19:54:50
Hi all,
I've been lurking this group since I got my first iblue gps device, and now finally here I am posting :)

Among others, I have a iblue 747 which felt into the sea almost two years ago. I thought it was completely gone, then playing around with the on-off switch, I found that it is still working through USB. And here comes the point.

I'm willing to build my gps tracker which sends data over GSM. I thought about reading NMEA data out of the USB connection, but it would require too much effort on my PIC (PIC18F13K50). Then I found this ( where this guy takes NMEA output directly from his GPS module. Now, even though it is clearly a different GPS, do you think it would be possible to do the same with the iblue 747?

I've seen that the trick to extend Bluetooth functionality makes use of some pins. My 747 has the same connections of the picture in second post (the one from José Araújo). In the third picture you see GRX, GTX and POWER (at the center of the bottom). What are they? Do you think I can get any serial output from there? I really hope those RX and TX mean Receive/Transmit :D

Anyway, thank you all.

Bye bye
pjay Posted - 01 févr. 2010 : 20:07:05
my iBT 737 looks different!

how can I unlock the 5hz mod on it?
mdeweerd Posted - 29 nov. 2009 : 23:48:30
Thank you for the microdonation - it is always a pleasure to see a token of recognition.
wilfred Posted - 29 nov. 2009 : 23:10:21
Yes I did that (stop on full, then erase), so the crazy stuff made sense after all.
(I thought I was going crazy). Man, you know what you're talking about.
I made you a micro donation. But you're worth every penny :-)
mdeweerd Posted - 29 nov. 2009 : 20:51:58
'Normal Download' - I forgot: the standard application downloads everything when in overwrite mode, so I think I made BT747 do the same (but I would need to check that). Anyway: I try to keep it as safe as possible (no loss of data).

The first block is not in overwrite mode only if you set the device to 'Stop on full' followed by an erase operation. Surely something like that happened.

You are pretty lucky with your PPC since the bluetooth supports the big chunks. The 'smart download' will download the data 'incrementally' so when traveling you can fetch the log 'daily' to get yourself a backup copy and to limit the download time per session.

wilfred Posted - 29 nov. 2009 : 20:13:26
You're of course most welcome. I hope it helps. Thanks for the support!

Ok for minimizing the record size. I'll use your recommandations.

I agree that it is strange that the A+ would conclude low activity when it's read by BT747. But so far no better idea. I scanned the ether, but no other BT activity over here that could interfere. It's just the PPC and the A+, running on their own battery... I hope it won't bother me anymore since the change to larger chunksize.

Another strange one. Some posts ago you write:
" 'Normal download' will only fetch the 9% (rounded on 64kB boundaries) but will start from 0 "
But whatever I try it keeps on downloading the full 4MByte. both PC and PPC. Do I do something wrong, or is it maybe an unintended change that slipped into the program code?

BTW: the A+ doesn't like the abort download by disconnect.

Oh no. UPDATE: what happened? I changed some settings in BT747, I don't remember exactly which ones (logging options etc) , but now the 'Normal download' is suddenly fast as you said. Both PC and PPC. I'm flebberguested! I tried it sooo many times, how can it change all of a sudden. My guess: be happy and don't touch it anymore :)

Now = time to relax in a different way :)
mdeweerd Posted - 29 nov. 2009 : 18:58:04
In theory the iBlue 747 (A+) does not officially support data download over bluetooth.
While I guess that there is a way to turn off the low power feature, I do not know how.
Based on your finding it seems recommended to reconnect after a while.

Given that the TOMTOM application is entirely passive - it is very strange that the device would conclude that there is no activity when there actually is a lot.

I should add log download cancellation - for the moment you can cancel by disconnecting.

Optimising the data downloaded is possible in all applications and you get some feedback about how many positions you'll be able to log in the logger based on the setting.
There is no influence on precision - logging is just observing what the GPS is reporting.
I recommend to log as a minimum: UTC, LAT, LON and PDOP. I use PDOP to determine the precision of the position (there is a filter in BT747). All other fields are up to your likings. RCR is needed if you want to know why the position was logged (button, special waypoint, speed, distance, ...).

Thanks for your feedback ;-).
wilfred Posted - 29 nov. 2009 : 16:57:29
Well. Experiments have led to the following:
the larger the chunk and the larger the # of requests, the better the datarate.
I could not find an optimum, just: the bigger the better.
But above certain chunk size, it does not help anymore.
The datarate that I achieved with 5requests, 100000 chunksize is
4.0kBps (32.1kbps)
The 4MB is downloaded in 17minutes.
My previous datalogger seemed to do this faster, so I checked objectively.
download speed of my previous datalogger+related PPC application:
Emtac Trine II gps-datalogger(sirf II), same PPC, Crux application
2.9kBps (23.2kbps), independent of baudrate setting.

So this means you have beaten the Emtac Trine PPC application. Congratulations!

So I thought that the TrineII was faster but apparently the TrineII stores much less data per gps point (actually: ~158bits versus ~3633 for the A+), so it could be downloaded faster.
My next question would be (if you are still interested), what would be the settings of the A+ to minimize the amount of data written per record, while still maintaining accurate location information, including height (I guess that should be sufficient to calculate actual speed etc. afterwards). What would be the drawback of such an optimization?

I was also experimenting with the switch you mentioned in the last post: "overwrite on full memory", but had some issues there. I was using the Desktop.
Sometimes the download took 3minutes, but most of the time 1.10minutes, I had the 3 minute thing a few times, but I don't know yet how to initiate consistently this strange behaviour, I tried already a lot. What didn't help, is that the Desktop software does not have a button to cancel the downloading of records, like the PPC version has (which was very handy during the download speed optimization).

Another, more interesting thing I observed. Maybe your software can be made more rugged. I have namely a clue why the download of records sometimes stops during the transfer of data.
Generally spoken, it appears that after 2.5minutes, the A+ in NAV modus terminates the BT connection with the PPC, if it is not connected to an application that *uses* the BT connection. (BT connection between PPC and A+ will dissapear from BT manager).
Strangely enough, it sometimes happens within the BT747 PPC application during datalog download, but never when I use the A+ in combination with e.g. Tomtom.
I think it is related to the chunksize+request setting. Originally it was set to 220 size+3requests. Maybe that is just on the edge of the threshold detector in the A+ that decides whether the BT is used or not. So, sometimes, when downloading the records to the PPC, the decision would be taken that the bluetooth traffic is so low that the A+ decides to switch it's bluetooth module to 'sniff' mode, thereby breaking the bluetooth connection with the PPC. Would it not be possible to turn off this low-power feature in the A+, when BT747 is downloading information, just like you turn off the datalogging of the A+ during such a transfer?

I must say, I'm really happy with your nice program!
mdeweerd Posted - 28 nov. 2009 : 22:36:44
If the device was in 'overwrite' mode on erase, then then entire content will be downloaded.
In overwrite mode, when filled, the device will overwrite from the start of the memory. It will also report that the memory is 9% filled while it is actually 9% overwritten. To make sure that all data is downloaded, the full memory is fetched. 'Normal download' will only fetch the 9% (rounded on 64kB boundaries) but will start from 0. Smart download catches up where it stopped or where logging stopped.
wilfred Posted - 28 nov. 2009 : 21:57:06
Hello Mario

Very useful info. And indeed completely understood :)
I will try to optimize soon. Maybe tomorrow. Today I did some
windsurfing with the device, so I have a nice log to experiment with ;)
Memory is 9% filled. 391924 (9236 records)

When I was downloading the data over BT today, the transfer stopped at ~ 387000b,
when I restarted the download, it stopped at 420276b.
when I restarted again (+reboot PPC, which may not have been needed but i was locking up the device at an experiment), it finished the download at ~2096920b, which equals roughly 2MByte. Calculated back, this 2MB took 41 minutes.

But regardless of the speed (which I will try to optimize later), I found it strange that the device downloaded 2MByte?
note: I can see that the 391924 (given by the program) / 2^22 *100%=9%.
Also 9236records/99061total=9% (all given by the program)

mdeweerd Posted - 28 nov. 2009 : 10:42:42
I am subscribed to this thread. Both here or are fine by me - it is just that this thread is getting quite long ... As I do not really look at new threadss on gpspassion, the only way to make sure I see the post is in this thread or in any content on

It could be that taking out the battery made a change - I would not know what it changed. One would need to have a pictures of the device configuration before and after that event to try to get a hint.

I would say that step 2 is now achieved.

Step 3 involves tweaking the chunk size and read ahead (= pipeline of requests). The timeout can be left intact.

What follows will be a bit too technical for most, but since our degrees are in the same field, I suppose that you can follow.
The bigger the chunk size is, the less overhead there is in the communication (NMEA response type, checksum, ...) and the faster the device chains responses (less time between NMEA sentences). However, that also means that if the FIFO on the receiving end is "small", that that buffer gets filled resulting in the loss of data. Loss of data means that a recovery mechanism requests the same data again. With a big pipeline, the recovery takes longer.
Making the chunks smaller means more overhead, but also more time lost between responses. That is where the read ahead requests come in. This builds up a pipeline of requests. The device will be sending a chunk of data but will already have received requests for N more. Having received the requests already, the throughput is improved.
Another factor is bluetooth. Compared to USB more communication problems occur. That automatically results in a random need for recovery sequences. Therefore, the chunk size should not be too big over bluetooth.

So ideally one requests big chunks in the absence of communication issues - this is the default setting in the desktop version. In the mobile device versions the chunk size is smaller by default. It can be often increased, but I tried to choose a 'safe' setting working on most devices regardless of the speed.
wilfred Posted - 27 nov. 2009 : 22:12:10
Hi Mario!

I was just subscribing to your internet site, to ask you the question too, and now you already reply to this post. Incredible :)
Happy to hear that I don't have to solder in the device too ;)

Well the thing is that I'm using my PPC to do the tests. I installed your software+superwaba and it runs on the PPC. But as soon as I connect to the GPS, the pocketpc freezes and has to be rebooted. The BT-port 6 that I use is receiving GPS data (checked with other programs, like tomtom, GPSinformation, VisualGPSce).

Because the other applications that I used don't give more info than NMEA data, I don't know how to perform your Step2/3. Could you help out on this ?

PS: Your BT747 program on the PC runs fine with the 747A+ by USB cable. I can download data, convert it (GREAT!), clear the memory. However, the thing I would like to achieve is to be able to do the same from the PPC (for travel reasons).
Do you prefer to have the discussion here, or on your website?

continued : Maybe good to add: I'm using a PPC:
-Fujitsu-Siemens LOOX720
-Windows Mobile 2003 SE
-Intel PXA272 520MHz processor
-126MB memory.


Somehow I got it running!
I have tried half an hour to make it again malfunctioning, but somehow it started working, and I can't make it crash anymore. It is very very strange. The only thing I can think of is: it may have started working since the moment I have taken the device apart, which involved taking out the battery ?!
Anyhow: the BT747 software runs now fine on the PPC.
The download of 19% memory took 15minutes.. Erasing took <1min.

Greetings & thanks for your help
mdeweerd Posted - 27 nov. 2009 : 21:54:01
Hi Wilfred
The iBlue 747 A+ should not have a hardware limitation for the bidirectional communication - the one I have doesn't.
Id did not check this on the A+, but what I observed in the earlier devices is that when the GP* sentences are turned off, the bluetooth communication is nil.
Do you get the current GPS position over bluetooth or not? That is step 1 to confirm connection and incoming reception.
Step 2 would be getting some of the other information related to the logger such as memory used which confirms bidirectional communication.
Step 3 is adjusting the download settings. This can be tricky and actually depends on the host - I think it has very much to do with the reception buffer size.
wilfred Posted - 27 nov. 2009 : 21:48:15
Hi José
Referring to your post some years ago of the bluetooth tweak of your Qstarz 810: I have bought an iblue747 A+ and it's a quite good device, but after 1 day trying to control it via bluetooth, I think I have a similar problem as you did at the time.
I tried to use the BT747 program from soundforge, but was not able to communicate with my device, whereas it's no problem via the USB cable.
Now the PCB in the 747A+ is quite different, I'm an electronics engineer, but I hardly see any resemblance :(.
So I was wondering: could you give me a hint how you would tackle this situation? (maybe you have found some documentation which helped you in locating the spot where the 1k was needed)
gr8 Posted - 08 nov. 2009 : 20:55:50
[quote snipped] I modified the file like you suggested and finally succeeded with installation, but bt747 won't start. Nothing happen when i try to run it.
mdeweerd Posted - 01 nov. 2009 : 02:23:00
The Nokia 6600 is listed amongst the supported phones on getjar ( It looks like they are wrong.

However, you can try to open the jar file like a zip and edit MANIFEST.MF in the META-INF directory of the jar. Change CLDC-1.1 to CDLC-1.0. [if you also use the jad ifle, you need make a change there too].
I believe that CDLC-1.1 is needed for floating point calculations. Possibly, that is not a problem for you purposes.

gr8 Posted - 01 nov. 2009 : 00:54:31
BT747 is not work with old Nokia 6600. If i understood corretly BT747 needs CLDC 1.1 and this phone has only CLDC 1.0. If i try to install BT747 i got error message "Wrong Version".

I like to use this logger in my RC-plane with 5hz logging, now i have to keep laptop with me for setting 5hz in flying field.

mdeweerd Posted - 27 oct. 2009 : 10:04:18
I am monitoring this 'thread' too ;-).
Several of the Holux loggers actually 'resets' some configuration settings to what Holux considers to be 'valid' settings. So setting the logging period to 0.2 seconds may work only until you 'power cycle' the device. Upon a 'reset' the firmware will check the values and bring them back to values that are 'in the list'. There is not much to do about it which is within reasonable reach. Users can always attempt to convince Holux to change that.

Further, the Holux M1000C has a slightly different protocol. To make sure that BT747 talks the right language, you must set the appropriate protocol throught the settings menu. This does not necessarily have an influence on your particular problem though.

BT747 also runs on mobile phones if the phone has J2ME (Java). There too, you'ld need to set the protocol to M1000C through one of the submenus.
gpspassion Posted - 27 oct. 2009 : 00:50:16
Welcome to the forums. If BT747 doesn't do it, nothing else will, ask the question in the BT747 topic that its author monitors.
gr8 Posted - 27 oct. 2009 : 00:40:07
I bought Holux M-1000C bluetooth logger few weeks ago. Is there any software to set 5hz loggin with old Symbian S60 V2 mobile phone?

MTKDlut and BT747 works with pc, but after switching device off the logging rate is back to 1hz, nmea from usb-port seems to stay in 5hz though.All S60 softwares i have found sofar needs newer S60 3rd version :(.
GastonLagaffe Posted - 21 sept. 2009 : 18:30:06
I really have no idea of what this part might be

I've tried to look in some supplier manufactures websites, but still no luck. I have even sent this picture to some suppliers in China ... but again ... still no luck.

Ho well, maybe I can figure out how the GPS receiver works, and maybe with a little luck and some external parts I can by pass this IC. I got to try it, when I get a little time.

Thanks anyway
mdeweerd Posted - 18 sept. 2009 : 00:10:54
;-(. Since you had to replace it you would have needed to get it out anyway.

I looked further to find a reference to the part but I was not successfull. may be a good source for searching part numbers but I did not have the required success.

I also looked on - no success there either.
GastonLagaffe Posted - 17 sept. 2009 : 23:40:02
Well, I did tried to pick it out, the result was a disaster.

The chip was soldered below with some kind of metal-to-metal aloy witch interconnet it to the ground plane in the other face of the PCB.

Unfortunatly it did not went well
GastonLagaffe Posted - 15 sept. 2009 : 22:06:14
mdeweerd: The link you've posted, its all exactly like the gps module I have. Thanks

I haven't pick it out and turned it over, but I'll tomorrow, after I'll let you know about it, and hopefully post here a picture of it.
mdeweerd Posted - 15 sept. 2009 : 14:31:27
I'ld agree that it has to do with the power when looking at this.

Did you check if anything is written on the other side of it?
GastonLagaffe Posted - 15 sept. 2009 : 13:49:20
Hi to all

I have in hands some modules of the 747A+ GPS datalogger produced by TRANSYSTEM INC. (I believe it's the latest version).

All those modules need one chip to be replaced, the GPS module is dead, and this happened after leaving it recharging.

I don't have the schematic, but I think the broken IC is related with power switching/management.

I'll include a picture of it:

The Ic has the following inscriptions on it:


Does anyone know what this chip is? or even its commercial reference? or its manufacturer?

Any help, would be great appreciated.

Kind Regards
gps007 Posted - 04 juil. 2009 : 00:18:45
I need a fast GPS bt mouse for Motorcycle-Racing-Logging and lap-timing and I have following questions:
Is there a big difference between the old MTK chipset (MT3318 i-blue 737/747) with 5Hz update rate and the new chipset (MT3329 i-blue 737A+/747A+) with 5Hz rate. The most important thing is that the laptimes can be meassured as accurate as possible. Things like a fast ttfx is not important for me. If there is no big difference between the devices i would buy the older one because its only half the price of the "up to date" mice.
Are there any other affordable solutions which are more accurate? I guess that the wbt-300 @ 10Hz isn't better than the mentioned mice because the data, the wbt-300 gets, is only interpolated? The software i want to use (gpsector) interpolates the data, too.
mdeweerd Posted - 29 juin 2009 : 14:18:45
1. You can use BT747. It appears on the main screen.
2. Yes you can. It is not required: you can get up to 5 positions per second - not usually needed. WAAS is not needed, it is supposed to improve precision but that is 'contraversial'.
3. No need to 'enable' it - just need to upload the AGPS (EPO) data to the device. That can be done with the 'development version' of BT747 or with the official tool GPSVIEW (though that does not work very well in my case).
mrQQ Posted - 29 juin 2009 : 13:54:02

i just bought a Holux M-1000C, which appears to have MTK II.


1. How do I check its firmware version? Is it updateable?
2. Can I set it to 5hz? Should I? Are all the WAAS things needed?
3. It does not seem to say that it sports AGPS support, but is it still possible to enable it?

bonzai Posted - 20 mai 2009 : 00:05:30
I have a Globaltop g66 nano receiver and unfortunately it shuts down after 5min without bt connection. It has the mt3329 gps chip and the mt6601 bt chip. I found one pin at the chip with
84k g4
c6kl c
on it which is high while it has bt connection and low if not. If I connect it manualy to high, the blue led blinks as it has bt connection and the device stays on, but with this mod there is no sattelite signal :(
Does anyone has modded this successfully or has info about the mentioned chip? Or a datasheet for the mt3329 chip?

mdeweerd Posted - 17 avr. 2009 : 18:54:20
I found the other hack:

This should make sure that the chip remains pozered (and keeps on logging) even if the BT connection is not active:
4river Posted - 17 avr. 2009 : 17:13:54
When i-Blue747 and BT-Q1000(M-core) feed power USB, it is not possible to download it from Bluetooth.
Please test download after disconnecting USB.

Download from Bluetooth under USB feeding power is possible since B-core.
mdeweerd Posted - 17 avr. 2009 : 16:14:55
The 1k resistor will allow you to download the data over bluetooth.
In the first versions of this device, the device is 'deaf' and can only talk over bluetooth. Adding the resistor enables it to also listen to the incoming data over bluetooth and therefore respond to incoming requests.
davatz Posted - 17 avr. 2009 : 11:09:43
Ah ok.. but.. the hack with the resistor 1k il necessary for what? I've not understood correctly..
mdeweerd Posted - 17 avr. 2009 : 10:07:50
This hack will not do that but I think I have seen another hack to make sure that the device remains active even in BT mode. I think on this site [maybe I'll do a search someday].
davatz Posted - 17 avr. 2009 : 08:52:04
Yes I know... but I want that the GPS log in every moment with BT in stand by . When i want to download data.. the BT lay me to connect.

mdeweerd Posted - 16 avr. 2009 : 16:20:37
You do not need the hack for that - the devices logs the data when the BT connection is active.
davatz Posted - 16 avr. 2009 : 10:23:56
I've bought a iblue 747 and i want ti hack with the resistance. I've opened and it is like the first photo page.

A question... I want to log my car... but not in real time... only read when I want via Bluetooth the log data. Tha hack (resistance) give me this possible?
yeryry Posted - 31 mars 2009 : 12:27:49
I've done the resistor mod on my 737.. Reset commands work, as does 5hz updates..
But I can't get it to go to SiRF mode what ever I try..
I've tried SirfTech, cemonitor and GPSTweak.. Nothing happens when I try to switch to SiRF, and it just stays sending NMEA..
Also, all the download links to are now dead..
v12mike Posted - 23 févr. 2009 : 07:53:49
I have recently bought a Globaltop G66 Plus with the MTK 3329 chip. The device seems to work very nicely, but the AGPS support program from GlobalTop crashes while finding a com port on my PC. MtkDLut talks to the device OK, but I have not been able to find a source of the ephemeris file to download. Any suggestions for getting AGPS to work?
gpspassion Posted - 08 janv. 2009 : 01:54:27
I'll let mdeweerd give you tips for BT747 but to have the most post-processing possibilities activate as many fields as possible, like distance, HDOP. You can then use the filters to clean up problems.
mgillespie Posted - 07 janv. 2009 : 22:35:43
Got a eBonTek 3200BT with firmware M-core_1.94 and logger S/W 1.31

Anyone know if the Valid Fix only mode works? Or do I need to also log NSAT and HDOP?

I am planning on using this to track some ski routes, off to French Alps next week, can someone recommend some bt747 quickstart settings?

I tried myself, and had problems with garbage data in the log when the GPS lost signal (as I went inside).
adarna Posted - 28 déc. 2008 : 23:03:54
Thanks again mdeweerd. I will try to find how to set up virtual com port in bluetooth, because I have an option to set up gps virtual com port but none in the bluetooth menu.

On the other hand, I have windows mobile 6.1 and in the bluetooth manager, after pairing the gps I don't have a tab to add a new outgoing port (to use it later in the configuration of the Intermediate Driver).


mdeweerd Posted - 27 déc. 2008 : 22:01:34
You need to set up a virtual com port on the PPC in a bluetooth system menu.
adarna Posted - 27 déc. 2008 : 21:30:28
thanks for you replay mdeweerd. I was trying with my ppc and the bt747 program and I steel haven't get the tracks with it. After trying with the pc I succeeded getting the tracks but by target was getting them with the ppc. When I explore the services of the gps with the ppc I only get one, "SPP Slave", so now I suppose that the problem is that I haven't the COM service. What I don't understant is why I can get the tracks with the pc. I'm lost..
thanks anyway
mdeweerd Posted - 27 déc. 2008 : 16:24:56
adarna - it is likely that you do not need the hack to get the tracks in bluetooth mode.
Did you try ?
adarna Posted - 27 déc. 2008 : 13:52:37

Hello! I have a Konet BGL-747 GPS data logger and reading this thread I wanted to do the hack resistor as José Araujo did, so I opened my GPS and for my surprise in my model I couldn’t see the TXD connector as you can see in the photo bellow.
On the othe hand, if I was able to do the hack, in my konet model I have to set the ‘log’ position to get the data tracks and the position wich activates bluetooth on the gps is the ‘nav’ one. So would it be possible to get tracks with hack resistor done?
Thanks in advance

gpspassion Posted - 16 oct. 2008 : 19:28:26
Nano Q1300 review now available -> - pretty good performance given the size of the device !
gpspassion Posted - 03 sept. 2008 : 20:04:03
I've just just received a Nano Q1300 test unit with the new MTK v2 chipset and I'm quite impressed so far, tiny, light, USB2.0 (?)

BT747 report its model number as being "8805(?)" is that an iBlue reference ? Firmware is : AXN_0.3-B_1.3_C01 (QST1300)
Faming Posted - 30 août 2008 : 16:07:13

As Transystem has used MTK chipsets in its GPS devices before (e.g. i-Blue 737 (a)) and the channel / sensitivity specs are similar to those of the BT-Q890 from Qstarz (b), it is very likely that the mobile Mate 886 and photo Mate 887 indeed house that new MTK chipset.

Unfortunately the leaflet is not very detailed. No mention of capabilities of the USB connection, POI function for the 887, and most importantly if the battery is replaceable.
10 Hours is not too much, but no battery can last a multi-day hike in the outback anyway! (This is b.t.w. the only shortcoming of the otherwise promising BT-Q890/1300.)

I haven't seen it for sale anywhere yet. Notice how the casing has changed colour recently (e.g. 887 checkerboard (c) vs green (d)), so it might not even be in production yet.

Also note how the sensitivity has increased from -162 (d) to -165 dBm (c). Qstarz still only claims -162 for its BT-Q890 (b). Something similar is true for the Skytraq Venus 6 chipset. The manufacturer claims just -158 dBm (e), but Sheng Jay's GPS data logger states -160 dBm (f). What are we to believe!?






mdeweerd Posted - 20 août 2008 : 00:57:58
A new MTK chipset?
mobile Mate 886 is reported to have 66 channels as well as the photo Mate 887 which is a logger with only 10 hours of battery life (according to the leaflet).
peppor6 Posted - 05 août 2008 : 19:54:03
hello I own a Qstarz BT 818
I did the modification with the resistor. I used a more little one, just 100 ohm. It works.
you have saved my life ;) i bought this receiver only thinking it worked at 5 hz! indeed i am going to use it with racetrack, a chrono for motorbikes and in this field it is really important to have 5 hz!! thank you!!

my version of firmware is ;
M-core_1.92,0005 1.902_48__1102_0005,0609_mA297,0002

Thanks a lot! i will come back after i will try on the field ;)
orenfl Posted - 04 août 2008 : 20:55:19
As a user of iBlue (MTK) 737 I enjoy 5Hz data from the unit to my Nokia e65 using Sygic navigation.
Yet, after a hard reset (power-off or battery removal) I'm defaulted to 1Hz which doesn't provide smooth navigation.
I got several PC software that by Bluetooth re-enable the 5Hz but was looking for a Symbian soft to provide the same service.
I searched around google quite heavily without any success.

Does anyone got a clue for a Symbian solution.

Nazar78 Posted - 15 juil. 2008 : 11:06:28
Hi all, I'm new to this forum. My 1st gpsr

Hi vhtija,

Seems I too have this disconnecting problem. I'm using M-1000 is B-core_1.0,0003. Ends with 3 if I can recall correctly. Showed as 115200, but when queried, it will return 38400.

Differs from your SE, I'm using Atom Life PPC WM6. The bluetooth disconnection will occurs after sometime ie. after 200+km on the highway. I thought it was my PPC, but only by turning on/off this gpsr device made the reconnection possible. I have my usb charger jack connected to my PPC all the time in the car, so no power management should occurs (set to no auto off when charging). Which gps software your using? I'm on MapKing 2007.

Com7->38400. Tried both 1-5hz still having this issue. Could it be the gps software is choking, hung and disconnect the bluetooth? I don't have others to test. Appreciate if someone can advise.

Thank you...

Originally posted by vhtija

Thank you, that is very informative.

>> If the connection drops, it might be because your mobile phone does not keep the connection 'alive'

Does this mean that my old GPSlim 236 (SIRF) didn't have this feature/ability (more like a bug :) ) to "cut" power when it detects a missing "keep-alive" signal, unlike the M1000 (MTK)?

>> If you look good enough, somewhere on this site is explained how to keep the device on in Bluetooth mode by applying a hack.

I will look for this and I hope this hack is valid for the M1000 (MTK MT3318 chpset)

mdeweerd Posted - 01 juil. 2008 : 00:01:38
I found a course in french talking about BT low power that includes a 'sniff mode'.

It does not provide full details. I did find a site with the bluetooth profiles:

The problem probably occurs in the low power negociation - either the GPS does not take the lack of acknowledge for a low power request into account - or - the phone/pda replies incorrectly (acknowledging the low power request for example).
saimhe Posted - 30 juin 2008 : 22:26:28
I never read those BT protocol specifications therefore it is obvious to me that a "Keep-Alive" should be done at application level. We don't have any alternatives, anyway. The problem so far, though, is where to obtain some simple software for testing (read from communications port and display cumulative amount of data, send a predefined string every few minutes). Ask a fellow programmer :)
vhtija Posted - 30 juin 2008 : 19:10:43
Does this mean that the NMEA data being transferred at 1 Hz isn't good enough as a keep-alive? So, under normal Bluetooth operation, is the data transfer completely one-way, with zero data being sent from the receiving side to the GPS receiver unit?
saimhe Posted - 30 juin 2008 : 15:14:07
A typical Keep-Alive: the receiving side should regularly send some innocent command (for example, version query). But if the problem is due to memory leaks in buggy firmware, likely nothing will help.
vhtija Posted - 29 juin 2008 : 20:17:26
Hello Mario,

Thanks for the effort. I did find this one while I was searching for the hack you mentioned, but this hack seems to be for a different chipset - the iBlue 737. The M-1000 PCB is very different from the modded picture shown in the link you mentioned. There are no apparent similarities I can use to perform the same (Pardusj's) hack. (For eg., I don't see a part "136X" on my PCB as shown in the picture).

Would there be a "soft" way to switch off Power Management on the M-1000? The factory setting for PWR_SAV_MODE seems to be 'OFF'. Nevertheless, I have also tried using $PMTK320,0 to turn Power Saving OFF. A $PMTK420 query confirms that it is indeed OFF. But the problem remains: There is still random Bluetooth disconnection. Any other ideas?

Thanks & Regards,
mdeweerd Posted - 29 juin 2008 : 16:41:02

Since you can't find it, I looked for it. Here is the link:

Kind regards

vhtija Posted - 29 juin 2008 : 15:53:14
How do I keep the M-1000 from going into the power-saving mode? mdeweerd suggested that there is a hack for this. I have been unable to find this hack. Can someone help?
poupou75 Posted - 24 juin 2008 : 13:41:32
GPSlim 236 has no power management inside.
If you switch it on, it will stay on until death, even if nothing is connected.

mdeweerd Posted - 24 juin 2008 : 11:48:03
Does this mean that my old GPSlim 236 (SIRF) didn't have this feature/ability (more like a bug :) ) to "cut" power when it detects a missing "keep-alive" signal, unlike the M1000 (MTK)?

This is patented 'smart power management'. You can't know if it is a bug or not until you look at the BT specification and look what is happening.
Your GPSlim probably did not try to save power by switching of the connection.
Further, a power down of your mobile could be more effective than a power down of your GPS. Your phone thinks it is still connected while it is not.
vhtija Posted - 24 juin 2008 : 11:11:01
Thank you, that is very informative.

>> If the connection drops, it might be because your mobile phone does not keep the connection 'alive'

Does this mean that my old GPSlim 236 (SIRF) didn't have this feature/ability (more like a bug :) ) to "cut" power when it detects a missing "keep-alive" signal, unlike the M1000 (MTK)?

>> If you look good enough, somewhere on this site is explained how to keep the device on in Bluetooth mode by applying a hack.

I will look for this and I hope this hack is valid for the M1000 (MTK MT3318 chpset)

mdeweerd Posted - 24 juin 2008 : 10:41:09
Bluetooth does not have a notion of serial speed in that sense, neither does USB.
For USB, I have the impression though that the driver transmits the serial speed to the USB slave which uses that information to set the serial link speed. This is possible because the driver is provided by the vendor.

For Bluetooth, no specific drivers are installed and the serial speed on the host is very likely not used.

Both on USB and Bluetooth a 'serial profile' is used - a kind of channel is created on the USB/Bluetooth connection. Packets go hence and forth to 'emulate' a serial connection.

If the connection drops, it might be because your mobile phone does not keep the connection 'alive' (whatever it is that is needed to keep it alive). Therefore, the GPS module thinks that the connection is no longer there and 'cuts' the power.

If you look good enough, somewhere on this site is explained how to keep the device on in Bluetooth mode by applying a hack. That might be sufficient to keep your device working with the mobile phone.

I have a Palm Livedrive and I do not have this kind of problem with my iBlue 747. Officially, the documentation says that the device is incompatible with palm devices - so what you are observing might be a similar problem.
vhtija Posted - 24 juin 2008 : 07:34:42
Thank you for the response.
Assuming the 115200 to be the internal communication speed, how would I then check the bluetooth serial connection speed of the M1000? How do I ensure it matches (or locks on to) the speed of my mobile phone's BT radio? My problem is, as I mentioned earlier, that the bluetooth connection drops within a couple of minutes, and only a re-start of the M1000 will allow connection again (for another couple of minutes)!

Can someone verify if the 115200 I am seeing is the default for the M1000 and also that the remaining flash changes would be zero on purchase?
mdeweerd Posted - 23 juin 2008 : 19:17:19
The first number returned by the PMTK590 is '0' which means that you have 0 attempts left to change the flash settings - which means that you can not change these numbers.

Lucky for you - your device would probably have been broken if you reprogrammed this. This speeds probably sets the 'internal' communication speed and if you change that, this communication would no longer work.
vhtija Posted - 23 juin 2008 : 17:23:35
Hi all!

Earlier, I had a GPSlim 236 BT GPS receiver which worked fine with my SE P910i phone. I recently purchased the new M-1000, which stops being detected by the phone after a few minutes (as low as 2 minutes sometimes). The only way I can re-establish the Bluetooth connection is by switching off and switching on the M-1000.

The firmware version of my M-1000 is B-core_1.0,0002

Is this the latest firmware for the M-1000?

My M-1000 connects to my computer via USB-serial port at 36400 baud, but querying the flash memory user setting with $PMTK490 gives


which clearly shows 115200 as the NMEA Baud rate. Is this a problem? I am unable to change this baud rate to 36400 using the command $PMTK390,1,1,38400,0,1,1,5,5,1,0,0 or $PMTK251,38400

Also, from the above query result, I can see that the number of remaining changes that can be made to the flash is zero! Is this normal for a brand new M-1000 ?
Any help in solving the problem of bluetooth disconnection will be much appreciated.
alex.69 Posted - 13 juin 2008 : 11:25:22
Does anyone know if whit the new MKT 51 Channels.
Whit NMEA data MCHN - on

In command $PMTKCHN, how many data fields are received, 51 or 32 ?

cks2008 Posted - 08 juin 2008 : 19:50:27
TMK, the end user cannot update the firmware on MTX based GS loggers/receivers.

Bcore is the newer platform version.

I am not familiar with that software to say enough. Perhaps the BT747 MTK configurator app may help.

Lopesco Posted - 08 juin 2008 : 13:16:42
Hi there!

My name is Joào Lopes, I'm from portugal, and i'm the owner of a M1000. I'm having some problems with my gpsr... Some softwares, like geocache navigator, can't comunicate with the holux. The firmware version that i have, according to minigps it's B-core_1.0 0012. It's this good? Or bad?
Can I update it? If yes, how?

Thanks for the help that you can give.

Best regards

Joào Lopes
crisscross Posted - 04 juin 2008 : 02:59:29
For anyone interested I just received the Qstarz BT-Q818 eXtreme and GPS-view reports: "B-core_1.1,7401,,"
cks2008 Posted - 28 mai 2008 : 01:52:09
Supposedly the later ones with 32Mb have BT fully two-way out of the box, and are the one chip variety (like mine is).
doms Posted - 27 mai 2008 : 12:40:01
Originally posted by cks2008

Version 1 (the ones with two cans) has separate GPS and RF processor chips (MT3301 and 3179 respectively), ... These have the M_Core firmware.

Version 2 (AKA REV B, or QStarz Q1000P) has one can, with the RF and processor in one chip, an MT3318. ... These have the B_Core firmware.

Which of these two versions is able to send commands by bluetooth without the resistor mod?

On ebay someone offers an new iblue 747 32MB and 51 channels version with the MT3301+MT3179 chip combination. Does that 747 need a resistor mod?

cks2008 Posted - 10 mai 2008 : 02:19:12
I just bought an iBlue 747 REV B, and read mostly through this and some of the other BT747 threads, and thought I would just throw a couple observations in.

Mostly, I observe, that there is two versions of the MTK based receiver platform out there

Version 1 (the ones with two cans) has separate GPS and RF processor chips (MT3301 and 3179 respectively), and the Bluetooth module on those units has about a 30 pin module, with external Flash on the BT controller chip. These have the M_Core firmware,are marketed with support for 32 channels, and need a resistor added for two-way Bluetooth. The Rev A BT747 has a silver case.

Version 2 (AKA REV B, or QStarz Q1000P) has one can, with the RF and processor in one chip, an MT3318. The log EEPROM on the logger versions are outside of the can, and 32Kb (it is inside the processor can on the V1 units, and 16Kb). Bluetooth is on a simpler module, with an all-in one MT6601 chip, and 10 connection points. It is also missing that row of serial connection points opposite the USB connector (at least mine does). These have the B_Core firmware, are marketed with support for 51 channels, and do not need any modification for two-way Bluetooth. The Rev B BT747 has a black case.

iBlue markets their Rev B units with 150 000 points, whilst Qstarz markets theirs with 200 000 points memory. Just an observation.
Mind you those are observations and should not be taken for fact.

It seems most vendors are shipping the Rev B, where possible.

Modified 2008/6/5 - Clarified some differences.

iks Posted - 24 avr. 2008 : 07:36:41
Really! Thanx for reminding...

When I just bought i-blue 747, tried to connect via bluetooth (by mdeweerd's BT747 control), and nothing happened. May be, devices were not paired...
mastalee Posted - 23 avr. 2008 : 15:56:02
Originally posted by iks

well, can anyone help me: where to put resistor on my new i-blue 747?

Hi the newest version of the bt-747 already has the tx pin of the bt connected to the rx pin of the mtk gps chip.
so no resistor mod is needed ;)
cratf Posted - 23 avr. 2008 : 08:00:29
i just purchased i-Blue 737 and it has fw version b_core 1.1 0100. Does anyone know if this is the latest, and if not, where/how i can upgrade?
iks Posted - 13 avr. 2008 : 23:20:59
well, can anyone help me: where to put resistor on my new i-blue 747?

fenger Posted - 12 avr. 2008 : 04:12:56
Originally posted by JJones

iTrek Z1 / iBlue 757 Resistor Hack

Thanks JJones for the tips to modify the Z1 without opening the case. Just wonder though, how do you open the case? I cannot find a way to do it.
Oznog Posted - 04 avr. 2008 : 03:46:52
So lemme jump in here- is it correct that there's no way to get the MTK device (M3318 chipset) to output the raw pseudorange data like you can do with the SiRF -III binary protocol?

I didn't see it in the spec, unless that's the "$GPGRS (Range Residuals)" part.
musky Posted - 04 avr. 2008 : 01:49:23
FWIW, I have a newer 737, and mine will listen to commands, but I guess that doesn't help your problem at all. I'm not sure what is wrong there. I was wondering what you need to change. I'm not sure anything you do will help your problem, if it's the LSB (low speed bug).
Matl1982 Posted - 03 avr. 2008 : 13:43:10

I have the Iblue-737, the layout looks lite the one from Akyno. But if I connect the GRX and BTX point there is no change. I cannot read the firmware-version or change anything. The resistor is soldered correctly.

Has the manufacturer changed something to prevent that hack? I need it because geocaching is almost impossible with that mouse and the missing track angle.


gec Posted - 20 mars 2008 : 15:48:07
on a side note, MiniGPS (1.3.2) can parse PMTKCHN, and displays it under the 'Channel' tab. It contains SVid, SNR, Status.
musky Posted - 15 mars 2008 : 19:05:14
Yes, I get the CHN and ZDA command too. The Transystem spec sheet says the CHN command is "GPS Channel Status"
mdeweerd Posted - 15 mars 2008 : 15:42:15
I tried setting GRS and GST on my iBlue 747 using BT747.
When checking the setting, it is clear that the dvice just ignores the values:

Interesting enough, since I tried to activate all the NMEA data, I get this kind of info:
43984 - <
Archie2008 Posted - 15 mars 2008 : 14:05:50
Many thanks for reply.
One guy from other forum could not make his MTK receiver to output GRS. I don't know why manufacturers hide the accuracy information that hard.
musky Posted - 15 mars 2008 : 13:51:19
I have a 737, not a 747 BTW.... I looked a little harder at the spec sheet, and I did find the command to enable the GRS and GST commands. It is PMTK314. The unit does acknowledge that command successfully, but the unit does not send GRS or GST. It's probably cause I have a 737.....
Archie2008 Posted - 14 mars 2008 : 17:54:47
I thought this tool can do it, but not sure:
On screenshot in manual I see the tab to configure different NMEA headers (tab Othr->NMEA Output).

Add-on: official GPSview, Setup tab does not include the GRS message. GRS is mentioned in "EB-230 Data Sheet" and is included into "MTK GPS Datalogger Device Control" above, but need to check if there any real data sent, or just zeroes.
musky Posted - 14 mars 2008 : 16:57:40
I'd be happy to post it, if you can tell me how to get my MTK unit to output $GPGRS ! I am looking at the Transystem data sheet for the NMEA protocol and extensions for the MTK, but I cannot find any mention of that command.
Archie2008 Posted - 14 mars 2008 : 15:32:22
Hi, did anybody manage to output the $GPGRS record (Range Residuals) from MTK based receivers ? How does it look ?
I'm an owner of SiRFIII which is not capable for this sentence.
Could somebody post some messages including GGA, GSV, GSA and GRS please (2-3 cycles is enough). I have an idea we can estimate position accuracy from these and check if there is a signal multipath from any satellites.
sysmg Posted - 11 mars 2008 : 17:11:18
FYI. I purchase a Freedom Keychain GPS 2000. It has firmware B-Core_1.1 8600.

mdeweerd Posted - 23 févr. 2008 : 22:16:22
I discovered something strange.

I thought that the *DOP values would be BIG when there is no fix. That seems to be the case most of the time, but there are some exceptions. Any idea/remark?
Here is an example:

1949,,2008/01/31,16:09:25,No fix,48.932492,N,2.189227,E,155.024,9.866,2.64,,,
1950,,2008/01/31,16:09:27,No fix,48.932577,N,2.189969,E,152.906,1.196,1.77,,,
1951,,2008/01/31,16:09:29,No fix,48.932672,N,2.190663,E,152.672,1.363,1.41,,,
1952,,2008/01/31,16:09:31,No fix,48.932773,N,2.191316,E,153.142,0.818,1.44,,,
1953,,2008/01/31,16:09:33,No fix,48.932870,N,2.191945,E,153.330,0.994,1.41,,,
1954,,2008/01/31,16:09:35,No fix,48.932961,N,2.192550,E,153.387,0.177,1.25,,,
gpspassion Posted - 23 févr. 2008 : 02:01:13
Semsons M7 and Qstarz BT-Q1000P added to the first page, note that the BT-Q1000P has the "resistor" hack implemented at the factory ;-)
Akyno Posted - 05 févr. 2008 : 17:34:19
I soldered as described above. Works like a charm.

B-core_1.1_0100 is running on it btw.
Akyno Posted - 05 févr. 2008 : 14:59:15

Today I would like to apply the Resistor Hack to my Qstarz BT-Q818.
Apparently I have a new revision of the hardware. I found the layout here on the forums. I'll just relink the images, hope thats ok.

The points to connect with a Resistor are labled differently as pointed out in the descriptions. So I just want to be sure.
I assume I have to connect the GRX and the BTX point.
Is this correct? I will use a 1KOhm 0,2 W Resistor.

Thx for help
sycorax Posted - 01 févr. 2008 : 23:16:33
Great Forum ! I just teaked my 747 and put a 220 Ohm resistor in ( the one that should be there is 470 only ). Works perfect now, I can place commands and enable 5Hz via bluetooth.

I run BT747 on my new T-Mobile MDA Touch Smartphone. I need the device to measure the speed of my small turbine powered jet. If anybody is interested:,de/

The Jet is only 90cm , made of foam but supposed to go >250 km/h
mdeweerd Posted - 29 janv. 2008 : 16:20:16
Let's say that my SW manages the time information correctly in the KML format and that the Qstarz SW does not translate that information in the best way in the KML format. As GE does not see the time, the track is 'timeless' - it is mentioned in the comment strings I believe.
ark19 Posted - 29 janv. 2008 : 15:01:55
Originally posted by mdeweerd

Do note that in the upper image you only show the points between 10:51 pm and 11:27 pm. You need to select the full timeline.
In the lower image there is no timeline - possibly because the time information is not written to the KML file?

The strange thing is only the direct KML from your sw had the timeline. The Qstarz sw does not have any options while saving the KML file. But it's not a prob for me :)
ark19 Posted - 29 janv. 2008 : 02:07:11
Originally posted by mdeweerd

Do note that in the upper image you only show the points between 10:51 pm and 11:27 pm. You need to select the full timeline.
In the lower image there is no timeline - possibly because the time information is not written to the KML file?

Thanks for pointing that out Mdeweerd :)
I'll try and figure out later tonight.
Don't recall any options regarding the KML output for the Qstarz software. Cheers :)
joeyshortshift Posted - 28 janv. 2008 : 22:26:01
Update: I applied the jumper hack to my 737 (thanks Pardusj) and now it streams NMEA data from the usb port at 5hz without going into power save mode. Thank you Mario, José, and Pardusj.
joeyshortshift Posted - 28 janv. 2008 : 21:02:11
Mario, you rock!!! I've spent most of this past weekend trying to find that exact info. Thank you so, so much.

BTW: Kudos on your config app. Very nice.
mdeweerd Posted - 28 janv. 2008 : 20:27:17
Oh no, I perfectly understood!
The answer is actually in this thread, on page 16:
joeyshortshift Posted - 28 janv. 2008 : 20:20:46
Originally posted by mdeweerd

'joeyshortshift': somebody already explained a BT hack somewhere on this site: I think it is in the iblue 747 topic.

I think you may have misunderstood what I was trying to accomplish. I am trying to log data through the USB connection on my 737 without a BT connection. José hooked me up with the info I needed to patch in the CP2102 serial connection for rx/tx to the MTK receiver. Now I am experiencing an issue similar to using the 747 in nav mode with only the usb connection. After three minutes the 737 goes into power save mode if there isn't a BT connection. I am trying to figure out how to disable the auto off, power save feature on the 737. There are two conceptual solutions that I can think of. First would be to hack the firmware and disable the power save functionality. The other would be to identify which circuit on the BT transceiver is hot when there is a connection and trigger it when there is a USB connection. Any suggestions on how I may find more info regarding these possible solutions?
mdeweerd Posted - 28 janv. 2008 : 19:13:39
Do note that in the upper image you only show the points between 10:51 pm and 11:27 pm. You need to select the full timeline.
In the lower image there is no timeline - possibly because the time information is not written to the KML file?
ark19 Posted - 28 janv. 2008 : 16:58:24
Hi Mdeweerd, I'd just downloaded ver 1.29, thanks for adding the indication when writing to gpx and other files :)
Would also like to check something with you.
When I use the sw to download the kml file, some points are missing.
However when I use the sw to save as csv and use Qstarz's Travel Recorder PC Utility to open the csv and save as kml, the track looks better and points are clearly indicated with flags (per 100m as I'd set).

Direct KML


Any settings to get the same results?
Thanks :)
ark19 Posted - 27 janv. 2008 : 18:44:48
Thanks Mdeweerd :)Cheers
mdeweerd Posted - 27 janv. 2008 : 17:45:02
One suggestion for the software, possible to implement some sort of indication that it is writing the gpx, csv kml etc. files?

OK - I did something - it will be available in V1.29 - it's uploaded now.
ark19 Posted - 27 janv. 2008 : 15:14:47
Hi Mdeweerd, thanks for your help :)
Finally found out the prob.
I couldn't set to the com ports as my ppc only had 2 ports, 0 & 6.
Both were used. I deleted the 2 previous mapped ports.
Tried using com 0 but couldn't get the connection.
Then I tried com 6 and finally got the connection :)

One suggestion for the software, possible to implement some sort of indication that it is writing the gpx, csv kml etc. files?

Thanks for a very useful software, it should have been included in the gps package :)
mdeweerd Posted - 27 janv. 2008 : 14:07:25
Also have a look here:
mdeweerd Posted - 27 janv. 2008 : 13:18:11
I found this on another forum - hopefully it rings a bell:
After having connect your device once over USB to the WMDC in BT device manager in your PC add an incoming port i.e. COM3, now go to the Mobile device, turn on BT, open BT manager and in the setting under Com port tab add the same # COM port, if you can't find under COM scroll to BTS, it doesn't matter where the port number is located. Now go to WMDC click your Device icon go to Connection Setting and instead of leaving the default Bluetooth for others device scroll to the number of Com port you choose before COM3. Try to connect from device et..voila. I really would like to know why u have to guess always everything with Microsoft and paying and never being paid for my long night spent to solve their problems.

Comments are wellcome.

mdeweerd Posted - 27 janv. 2008 : 10:39:02
The documentation in the SuperWaba code says:

/** Bluetooth: open the built-in Bluetooth discovery dialog,
* then establish a Serial Port Profile (just serial emulation across
* Bluetooth, using the RFComm BT layer) virtual serial port connection.
* Note: in WinCE, this maps to the Serial (port 0). You must explicitly
* map your BlueTooth outside SW.

Maybe should should not map it to a bluetooth serial port?

Further, I guess that there is an equivalent 'number' for a bluetooth serial port.

In the application, you normally have to use the bluetooth button on a PDA, unless you are able to map it to a 'serial port'. You can try port '0' for starters according to the text above.
ark19 Posted - 27 janv. 2008 : 00:32:26
Hi Mdeweerd,
Com port was not selectable, the option with the port numbers did not have numbers.
I was able to connect it via bt with my PC.
mdeweerd Posted - 26 janv. 2008 : 22:21:25
Did you try a COM port in stead of a BTS port name?
ark19 Posted - 26 janv. 2008 : 15:45:01
Originally posted by jm_araujo

I think you mean GRX and TXD.

Hi José, I soldered the receiver but couldn't get it to connect with my PDA HP (Glofiish X500).
Below are the PDA screen captures:

#1-#2 Sw BT-Q100 to Nav, Search for BT device

#3-#4 Add to paired device, entered 0000 password

#5-#6 Unable to select port for COM, Index shows nothing

#7-#8 Able to select Port for BTS, selected 8 for Index

#9 Launched BT747, am I supposed to select Port number and click 'Connect Port' or just click on 'Bluetooth'? Both doesn't work.

Hope you can help
mdeweerd Posted - 26 janv. 2008 : 11:01:43
'joeyshortshift': somebody already explained a BT hack somewhere on this site: I think it is in the iblue 747 topic.
joeyshortshift Posted - 26 janv. 2008 : 06:32:33
Xevus: Which com port was assigned to your Serial Port Profile when you paired with the GPS? The first time around when I paired up I let Windows auto assign the port and it was like port 22 or something really crazy like that. I know the version of GPSView that I have only goes up to port 20. I deleted the bluetooth profile for my 737 and then paired up again. This time a manually selected port 7 since it was available.
joeyshortshift Posted - 26 janv. 2008 : 06:23:28
José, your my hero!!! I added the two resistors as you suggested and sure enough, I can now send and receive data via the usb connection. :)

I am now faced with a new hurdle. The 737 goes into sleep mode after 3 minutes if there isn't a bluetooth connection. Do you have any idea how I may disable that feature or fool it into thinking that there is a bluetooth connection?
Xevus Posted - 26 janv. 2008 : 02:27:26
I'm having troubles connection to I-blue 737 5Hz edition from PC. It works perfectly fine with my Dell Axim and iGO, but i couldn't figure a way to connect it to PC. What i have tried

1) GPSInfo from via BT. I have successfully paired device with my PC, but GPSInfo couldn't find device after scanning COM ports

2) Software that comes with receiver itself, named GPSView. It has very confusing documentation, to say the least. Based on that documentation it seems that GPSView doesn't work over BT. And actually doesn't work :). It also comes with some kind of USB driver, that is supposed to enable it to work over USB cable. But that driver didn't helped at all, this software still fails to find receiver on COM port.

Any ideas what is wrong ?
ark19 Posted - 25 janv. 2008 : 18:11:49
Oh, I'd thought it'll work with GTX.... Thanks for correcting me :)
jm_araujo Posted - 25 janv. 2008 : 16:50:27
I think you mean GRX and TXD.
ark19 Posted - 25 janv. 2008 : 16:25:14
Originally posted by jm_araujo

You are correct.
Following the GRX track you can see the pads of the missing resistor.

José Araújo

Thanks José, so in fact I could solder the resistor between GRX and GTX?
Will try it out tomorrow when I get the resistor.
Cheers :)
jm_araujo Posted - 25 janv. 2008 : 16:15:01
You are correct.
Following the GRX track you can see the pads of the missing resistor.

José Araújo

musky Posted - 25 janv. 2008 : 16:13:18
FWIW, I have the non-5HZ iBlue 737, and I can't do the proposed USB enable resistor hack. I don't have the bridge chip!!

BTW, in jm_araujo's instructions when he says crack the unit open with a knife at the "top" of the unit, he means the side AWAY from the LEDS and the power switch. I didn't look carefully enough at the photo, and I was on the wrong side. It's VERY difficult from the "bottom", and fortunately I realized my mistake and switched sides.

Also, the non-5HZ iBlue 737 actually does 5HZ FWIW.....

ark19 Posted - 25 janv. 2008 : 15:49:36
Originally posted by jm_araujo

I can only tell with pictures from the other side of the board.

José Araújo

Hi José, thanks for the quick reply :)
Here's the other side

I guess it should be GRX and TXD?
Thanks again :)
jm_araujo Posted - 25 janv. 2008 : 15:32:37
I can only tell with pictures from the other side of the board.

José Araújo
ark19 Posted - 25 janv. 2008 : 15:21:34
Originally posted by jm_araujo

Now you will have to solder a resistor as pictured next(shown aligned before soldering). I've used an 1Kohm and it works fine. Be carefull and make sure it doesn't make contact with anything else.


Hi guys, this is my first post ;)
Just bought the Qstarz BT-Q1000 and I'm going to do the resistor tweak.
Seems like the PCB is slightly different.

Are the 2 arrowed points the correct place to solder the resistor?

jm_araujo Posted - 25 janv. 2008 : 13:42:10
Crossing information from the datasheet of the Silabs CP2102, your pictures, and the FCC records internal pictures, I think there are two resistors missing, breaking the connection of the data lines to the USB IC.


If you solder any "generic" value resistor (1Kohm - 10Kohm) in there it should start communicating via USB.

José Araújo
mdeweerd Posted - 25 janv. 2008 : 11:13:33

Check if the bt747 application (or the gpsview application) returns the model number of the MTK chip. If it does, you do have control over the 737.

The 747 can be programmed to 5Hz with bt747 and it does send 5Hz updates.
gpspassion Posted - 25 janv. 2008 : 10:43:42
Welcome to the forums.
Yes I was going to suggest saving yourself the trouble and getting the 747 as it streams the GPS data over USB, besides I've seen dropped data via Bluetooth at 5Hz, so I think it would be a more reliable solution anyhow.

A bit OT here but for video+GPS you might want to take a look at
joeyshortshift Posted - 25 janv. 2008 : 03:51:29
For my first posting I would like to say that I learned more than I could have ever previously imagined about GPS technology on this forum. The GpsPasSion forum community is a great bunch of folks.

I recently purchased the i-Blue 737 5hz from Semsons to log closed circuit motorbike sessions on my bluetooth enabled PDA. After analyzing the data and trying to synchronize GPS data with recorded video that I took during the sessions, I thought it would be a fun project to piece together a solid state video recording system that can also log GPS data. Eventually I intend to log a few other analog signals as well. For hack-a-bility I chose the Neuros OSD as my recording/logging platform. If you are not familiar with the Neuros OSD, it is an embedded system running Linux that has been open sourced. The Neuros OSD doesn’t have a Bluetooth transceiver so I am trying to figure out if I can tweak the 737 to utilize the cp2102 USB-UART and stream NMEA data from the USB port.

I have read on this forum and a few other sites that the USB port on the 737 is only for charging and isn't intended for communication. I'm trying to find out if this is entirely true or if there is a tweak that will enable the USB port. There are a couple things that are keeping me optimistic about this challenge.
-First, the CP210X USB Windows driver was included on the CD packaged with the 737. If I connect the GPS to my PC with the drivers installed I am able to connect with GPS View v1.1.0 on a virtual com port that the driver creates. Yet, there isn't any data received and sending commands does not return any results. If I disconnect the GPS from the virtual com port and try to connect with GPS View, I receive the, "open com error" as one would expect. So that makes me think that I am in fact communicating with the CP2102.
-Second, after popping the cover off my 737, I noticed that the cp2102 circuit looks nearly complete. I am curious if there is a tweak similar to what José Araújo (a.k.a. jm_araujo) suggested for enabling commands to be sent via Bluetooth.

For you viewing pleasure I took some pics of the 737 5hz circuit board. :)

i-Blue 737 5hz Circuit Board – Top - High Resolution (1.3mb)
i-Blue 737 5hz Circuit Board – Bottom - High Resolution (0.7mb)

Does anyone have any ideas as to how I might be able to connect the serial data side of the CP2102?

Is the i-Blue 747 capable of sending 5hz updates through the USB connection once the update speed is changed with the bt747 open source project utility?

Does anyone know of a similar device that will stream NMEA data via USB at update rates of 5hz or greater?

If you know of anyone else that is working on a video + GPS recorder, I would love to hear about it.

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