yashsingh1/xdaforums huggingface dataset:
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] jpogge:
I agree, however if they were shorted they produce a signal that is essentialy the P - M thus the differential nature. And there wouldnt be any satellites in view. Did we verify that the satelites were also those seen on a working system, but not as many.

I will put a module together that has an active lna, HOWEVER, THIS WOULD NOT BE A KIT SOLUTION, the cost will be higher than a good BT GPS and sleuth is correct major surgery is necessary. At this pointthis has become an interesting exercise , not a potential solution. HTC has crippled the circuit, the only way to bypass means at least 4 solder connections, and possibly tombstoning the pins on the chip.. Since this is the GSM receiver as well Bricking is very likely... BT is the solution for GPS from a practical and cost side,, sorry guys..
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
we did compare hermes SV's & PRNs with gps enabled pdas & nothing matched. worse, I gps software enabled two hermes & they didn't match each other. conclusion: noise only. :(
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] vijovame:
I know it!

Can you post the pin out?

Thanks...
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
Unsticking FTTB... We can still access from the Resources thread.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] joej:
good exercise guys! but bummer nonetheless.. HTC could have included the GPS functionality for a BOM value of probably like $1-2
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] chymmylt:
Just reading over at Engadget about how Nintendo was going to geopositioning using the Wifi built into the DS as opposed to GPS -Not likely to ever be possible to implement on a TyTN but I just read this and thought - wonder if we could somehow tap into this - I found it interesting at least.

http://www.engadget.com/2007/03/05/nintendo-ds-does-geopositioning-with-wifi/
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] rainydaze:
Navigon

@chymmylt

Navigon does geopositioning for the pocket pc using wifi and cell tower locations to emulate gps. You can find it on the web.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
By popular demand, here's the relevant pinout information for the RFR 6250:

47 GPS LNA in

48 GPS LNA bias

1 GPS LNA out

5 GPSMIX_M

6 GPSMIX_P

antenna circuit to 47/48

1 out to matching circuit

matching circuit to 5/6
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] walshieau:
so does this mean that you have the antenna working or just found the relevant pinouts?
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
Just posting the pinouts for aspiring or proven RF engineers who want to try and work their own "FM".... :)

me, I've ordered a Garmin GPS10 (insert sound of thrown towel here). The power demands of an external LNA which can't be controlled with "AT@startgps" will make this infeasable.

At least I can say I'll be getting WAAS enabled GPS which is something the Qualcomm chip could never do.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
Many manufacturers do this in an attempt to continue the upgrade process... Palm was notorious for the "1 fatal flaw" syndrome....

I'll need hermes capabilities + GPS + better rez screen to upgrade I think. Imagine a TyTN with 640X480 screen + builtin GPS.

HTC... are you reading this? :)
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] walshieau:
mmm interesting... i might have to order one also :p.... i dont like the idea of having the GPS antenna power not being controlled....

edit... just realised WAAS is only available to North America... you lucky ba**ards!!!
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Arktronic:
You guys should have EGNOS.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Arktronic:
HTC Athena? (Well, aside from being gigantic compared to a normal PPC)
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
Correct. It's too big for me too. They're making 640X480 screens the same size as our Hermes screens now. The improvement in clarity will be dramatic
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] walshieau:
yes they are making them but HTC as usual have already slated new models for this year so we will most likely be seeing these new screens next year...
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Bibto:
Just Curious

I have just upgraded to the latest Cingular ROM on my 8525, and there is suddenly a link to "Get TeleNav". Does this imply that Cingular is enabling GPS on this phone?

Stupid me, ignore this post.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
You know, I saw that too. Cingular's service may work on an 8525 because it uses tower information as well as GPS to plot a fix. It's $5/mo though.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] kkiran:
Will the service be close to original GPS hardware?
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
don't know. The fact that they offer it on the 8525 means it might be worthwhile for a Hermes though...
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Arktronic:
It's nothing special. From the TeleNav website (http://www.telenav.com/cingular/):

(emphasis mine)
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Philux:
You have to have a GPS bluetooth receiver to use TeleNav

TeleNav Compatible Devices:(

I am trying this out. It might be worth while checking out.(Navizon Alternative to GPS) Uses cell towers and wi-fi to track your position just found it today, so I can not tell you if it works very well or not.:)
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Philux:
It is a shame that the GPS is going down hill. I wonder, and I know it has been posted before, but if there was a bluetooth GPS receiver that could be taken apart and intergrated (Placed inside) with the Hermes. I know the room is limited. So it is very doubtfull. But it would be cool.

Also it would be interesting to get our hands on HTC's New P4550 to see what hardware changes they have done. Only thing I notice is that the keyboard is on the right side, as to the Hermes is on the left. The front camera is on the left side instead of the right. The camera has been upgraded to 2.8MP but I would guess that the hardware would pretty much remain the same. Maybe this is why they used the Qualcom chip in the hermes, this could be their upgrade as we have been guesing.

I don't know if parts would be able to be ordered from HTC or not. I know of a guy who got qualified to order parts from Motorola but I do not know if this is possible through HTC. This is like comparing apples to oranges. However if possible this could be the way to get the parts we need to getting GPS to work in our Hermes.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] .VIBE:
Well, I got the Holux GPSlim 240, which is about as small as you can get. Works really well too (sirf3 chipset). Not an all in one solution, but you can carry it in your shirt pocket and not even know about it.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] chrisryn:
What did that Holux cost. I want to get a BT gps but all the ones I can locate are in the $200.00 range
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Arktronic:
I just found it for $85: http://www.buygpsnow.com/holux-240-holux240-holux-bluetooth-gps-holux-gps-holux-sirf-iii-616.aspx
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] .VIBE:
paid $60+shipping on eBay.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] futureshock:
i have an tomtom bluetooth:

http://shop.dantotec.de/product_info.php/info/p23768

slightly bigger than holux...
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] ygeller:
I bought a couple of weeks ago a BT GPS from EMTAC - the mini S3: http://emtac.com/products/bluetooth/minis3.html

Really tiny, charges from USB port and works great on the TyTN with Mobile Live, Google Maps and TomTom.

Highly recommended for $75
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] trojan9x:
there is a BT GPS on cingular's site for around $100
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Bibto:
Arkon Resources has one as well.

Check Arkon Resources as well

http://www.arkon.com/

Rick
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] trashcan:
I thought this is a technical forum for the hermes internal gps....but now we were all switched over to the external add-on bluetooth receivers.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] walshieau:
if you actually read the forum it would give you the reason why we are turning to bluetooth gps devices as the Hermes GPS antenna LNA requires power to be supplied to it (i think thats right) which cannot be controlled therefore would be running all the time and reduce battery performance...
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] futureshock:
can anyone say me how you did it with mobilelive, google maps ?? also theres an other app... calles map4pda... (this just receives maps from google and other providers)

problem is (within google maps) that i can't use the bt gps ... googlemaps says connecting to gps... then it stops with the no found error...

don't know what i have to configure that this works... ???

steve
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] zorrykid:
Passive?

Hi everybody.

But a passive antenna? ....Just more noise?
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] trashcan:
I understand what your point is..and I have been involved with this thread also. But shouldn't we still keep this thread as a hermes gps technical section. Maybe we should start a new thread for the external bluetooth instead of flooding this hermes internal technical thread.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
@zorrykid/walshieau: It is my understanding that LNA is required to boost signals to the point where GPS_MIX inputs can recognize them. jpogge believes that external LNA will draw about 20mA @ 3.3V
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Mosser:
What about using the MAX2655 GPS LNA ?, it only consumes 8.3Ma, surely that would be acceptable for a continuous current draw, I would think that most of us on here are charging our Herme's at least once a day ?

here's its specs

http://www.maxim-ic.com/appnotes.cfm/an_pk/1749
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] ?Glitch:
GPS Low Noise amplifier with Variable bias current and

Shutdown function

http://www.avagotech.com/assets/downloadDocument.do?id=2510

Wide Supply Voltage: 1V to 3.6V

Shutdown current : < 0.1uA

CMOS compatible shutdown pin (VSD) current @ 2.85V: 90uA

Small Footprint: 2x2mm2

Low Profile: 1.1mm typ

Typical performance @ 1.0V supply

S21 = 12.3dB

NF = 1.0dB

Ids = 3.6mA

Only question is if QC Chipset micro will support it...
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] jpogge:
I was actually looking at the max2655 as a possible solution, however you are ignoring the fact that the disabled LNA needs a bandpass filter, so an LNA to a Band pass filter, with a second LNA necessary to drive a low loss balun to drive the differential inputs of the GPS Mixers, they must both be driven of the internal circuitry will mask as random noise. The MAX2655 is rated at 10.1mA, the above 8.3 quote is for the MAX2654 which uses fewer parts but wont allow balancing with the most efficient bandpass filters, so a solution that provdes the mixer inputs with proper signal level can drain about 20mA. Also this can only be connected if the pins of the RFR6250 can be raised and disconnected from the connections HTC made to the ground plane.

All this can possibly be done but the LNA must be settled prior to the power up of the RFR chip or the subsequent floating inputs can cause oscillations which in the words of the manufactuer can seriously damage the front end circuitry. This makes our possible solution to the circuit even more complex, as the external LNA driver must be on and off at the same time as the RFR6250, or the part can be trashed. So we would need to not only supply the LNA with the same power as the RFR,( not tap the battery), but find a way to sequence the LNA power up to the internal standby sleep mode inherent in the qualcomm devices. For this reason the RFBIAS pin 48 was provided and could be used for power except it too is grounded and disabled internally. We know the pin but not the register and command set to control.

This quickly became a really messed up problem for finding a quick solution. If all of the above is done, the solution will cost about $70 US , people have been quoting less, but this appears to be using 1000's quantities, and no one on this board has indicated a desire to front the money for such discounts... The $70 is including the shileding, pcb, wires, parts etc and still the bricking possibilities are enourmous, not to mention the serious drop in power. Even if 8.3 mA was all your solution provided, the qualcomm LNA runs on 1.2mA. and that with the device intelligently switched off when not in use. I havent seen an unused IO pin we could program to do the same. It really is safer and cheaper IMHO to just use a blue tooth for this one. The chip set multiplexes the RF signals by switching very quickly so they do not interfere, it might not be a good idea to mount an LNA so close to the GSM circuitry that doesnt do the same.

The RFR6250 is a 1.5 / 1.8 volt part the max 2655 needs atleast 2.7, the resultant additional switcher would cause more noise and use additional mA, unless you tapped the battery directly and used a regulator which draws current and is always on,,,,which isnt advisable as this creates a potential current loop which can cause damage to the device as well.. Not an easy problem...
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Izzard-UK:
...plus a little extra heat generation, I imagine.

Right then. ** starts trying to cram the components of his BT GPS unit inside the Hermes case ** ;)
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] dutty:
how much space do we have left in the hermes case? and how big are the internals of such an bt-gps module?
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Izzard-UK:
Damnit. It doesn't fit very well at all.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] silent_killa:
LMAO!!!

Looks like you need one of those ext. battery doors for that, lol
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
Too funny.... I'd have used duct tape tho... :)

Here's my solution (click pic for more info):

Garmin Bluetooth GPS 10 with WAAS

Waterproof

Built in magnet for attaching to metal surface (can put it on the outside of a car) :eek:

positional accuracy < 3 meters

NMEA 0183 output

12 hour battery life

Stores pairing for multiple devices (using my TyTN & PC currently)

The "Sensor only" version (no gps software included) is about $110...
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Izzard-UK:
I don't think you're taking this seriously. Obviously you can't see through duct tape, which causes screen readability issues.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] chymmylt:
Yeah - I just broke down and bought a Bluetooth GPS myself, wish that it looked more realistic we'd be able to easily do it with the built in hardware but to say that looks dubious is an overstatement!

I ended up getting this one because my friend has it and loves it - he says it works just as good as his Holux but has like 4 extra hours battery time (in his usage - I think it's like 2 hours by manufacture's specs). It's a little bit bigger then the gslim 240 but it has a user removable battery and it's still not too big. It was also about the same price as the gslim ($5 more on the sticker but $3 less on shipping so it ended up $2 more shipped) Hopefully it'll work pretty well :)
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] chymmylt:
Hmmm - I think I'll find a happy medium - I'll still use the Duct tape (I mean you'd be foolish to do any project without duct tape) and duct it to the flap of the TyTN's case. Black Duct tape would be more fashionable but I'll probably use silver because you know, that's the way I roll!
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Mosser:
Thanks for taking the time to explain that Jpogee,

I can see that it does look like a lost cause too now !, I'm pretty handy with a soldering iron and used to work for harris semiconductors doing reflow work in their repair centre, but i dont fancy doing all that work to my phone, as you said, the potential to brick the phone is very high and not a risk worth taking in my opinion, and there would still be the software side to sort out,

I'm going off to buy a bluetooth GPS now then !! :)
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] futureshock:
Hi there...

a friend of mine have an p3300 (with integrated sirf3) and on the ext. antenna plug there stands explicit a "GPS" sign!!

we just looked then in an electronicmarket... and tomtom offers gps antennas... maybe if anyone has such one can just give a try in hermes...

unfortunately he doesn't bought the antenne... else i had tested it ....
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
@futureshock: On a Hermes, hi-rez pics clearly show the GPS LNA input pin soldered to the mainboard ground. Qualcomm's documentation says to do this to deliberately disable the GPS portion of the RFR6250 when its not being used. It's very likely (although not verified) that the gps MIX pins are connected together too since the documentation also says to do that.

Because of this, adding an external antenna will have no effect I'm afraid :(
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] futureshock:
mh... truly... but i don't know if the layout is near the same as in the 3300 it can be possible that we only have to solder the chip gps pins to the right solderpoint on board that we can add a gps antenne on the ext. antenna plug?? or did i think wrong?

steve
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] LinoX:
This is not really true.. we could desolder the pins from the board, lift them up and solder on them two very tiny wires..

The biggest problem seems to be the voltage to supply.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] mars_shot:
Even if the GPS antenna is missing and there is no way to apply one to the Hermes, is there no way to access the Assisted GPS data from the unit? It is my understanding that cellular devices in the United States (at least) are required by law to implement location-based services technology for Enhanced 911. From what I have read about A-GPS (http://www.radio-electronics.com/info/cellulartelecomms/location_services/assisted_gps.php),

a cellular device receives some GPS data, specifically Ephemeris GPS data, from the network. The device can then more easily establish a satellite fix.

It seems to me that on the US models, the unit should be receiving some sort of location-based data.

Psiloc (http://www.psiloc.com/index.html?id=272) has developed software for certain Smartphones that can access location data without an external antenna or receiver.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] manou:
Hi,

I am a new member and have been following this forum from the moment I got my Tytn with great interest and hopes.

There are some issues that are not clear to me:

(1) Why is the effort around re-inventing the gps circuitry (LNA, matching components, etc) rather than copying one for one what is used on Trinity?

(2) Even if Trinity reverse engineering is too dificult it too should have a solution for powering the LNA only when needed (like via a GPIO), if so this should be possible also on the Tytn.

(3) The issue of lifting soldered/grounded pins is not an issue - we do it at work all the time on devices like that.

Regards.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
Well, the Trinity takes advantage of the RFR6250 LNAs that are designed for that purpose. They get powered up when the "at@startgps" command is sent. You are correct in that if we lifted the pins we could use them and solve the power problem but it would also take 5 connections to the chip (antenna, antenna bias, LNA out, GPSMix_p, GPSMix_m). Also, we need to locate our antenna/matching circuits outside the designed "Faraday cage" surrounding the RF components which would require a very fine 5 conductor shielded cable along with component shielding for the circuits themselves.

Not impossible for sure, but not practical either. :(
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] LinoX:
<joking>

This is a

too much

technical response.. or at least too much for a first-time /single post user. Tell us the truth.. You're an HTC hardware engineer sent here (from HTC marketing) to give us suggestions so we can made the GPS work on the hermes and you can sell more devices!! :D

</joking>
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] manou:
Upon further reflection, you don't need power control at all.

Switching on or off of the LNA is done via the bias current. In other words connect the LNA to the bias and you are set.

When you give "startgps" (or whatever the SW command) the bias current source is allowed enabling the LNA. Without the bias source there is only leakage current which is negligable (The MAX2655 is 100nA).
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] manou:
No, I'm an EE.
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] manou:
I can see that there are quite a few mistakes made in the assumptions up till now:

(1) As detailed in the spec of the MAX2655 (http://datasheets.maxim-ic.com/en/ds/MAX2654-MAX2656.pdf) "A shutdown feature in the MAX2654/MAX2655 reduces operating current to 0.1μA, eliminating the need for an external supply switch."

(2) Although the RFR 2655 uses 1.8V and the MAX2655 needs 2.7V there should not be a problem. Boards like these usually take the basic voltage source (say 4.5V) pass it through a number of DC switching converters and/or LDOs to obtain the variety of voltages needed. One of these voltages would surely suite our little LNA.

Questions:

(1) Does anyone have any Hi-Res pictures of the Trinity that show what LNA it uses? If so it should not be too difficult to get the reference circuit that accompanies it.

(2) Can Sleuth (or anyone for that matter) send me the reference design some of you seem to be quoting?
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] Sleuth255:
The Trinity uses the built in LNAs available on the RFR6250.

Unfortunately, I've not been given permission to release any more info on this chip than I already have. The Qualcomm RFR6250 technical information is covered by NDA for reasons beyond my comprehension :rolleyes:

How would you control the bias current to an external LNA so as to eliminate power consumption when GPS software wasn't actually using the hardware manou?
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] manou:
Sleuth, external LNAs are used in many mobile device applications. It is standard procedure to use the bias to shutdown the LNA. I am of course presuming that when the GPS is not turned on the bias current is switched off. The bias is a current drain (via a resistor usually) that when switched off does not allow the operation of the LNA.

Just looked at the qualcom 6250 page... Yep I see it, integration of: receiver + LNA + GPS. Why the hell can't we use the internal LNAs then?
[8525, TyTN, MDA Vario II, JasJam Software Upgradin] manou:
Just thinking out load here, why are we using an external LNA again?

http://www.cdmatech.com/download_library/pdf/diagram_msm6250_cs.pdf