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Modify any USB GPS to XDA Serial RS232, afterrnoon project

You have a USB GPS which you dont use, or dont know what to do with ? Well :arrow: Do not despair, heres your solution.
I kinda got bored the other day, no Mobiles to repair. So... I ripped apart my USB GPS which I didnt use for my lappie anyway, too bulky to drag around I found out after a while, and to use GPS in the home hehe well...
What you need :
1 : USB GPS any make
2 : Soldering iron 30~50W with small tip, I prefer SMD 1mm tip
3 : Soldering iron 60~80W for removing RF shields
3 : Some wires, I'm sure you have'em somewhere
4 : Old GSM mobile cable for COM port which have seen better days
5 : Some good flux
6 : XDA connector
Now, most USB GPS have only output for USB, some engine boards if your lucky have also a real RS232 output, but they are few.
The engine board I used is the BU-303 (note: similar to the EM-401 engine board with 2 output connectors, but be aware for some strange reason both outputs are USB only !) All GPS which are enabled with USB you can convert to RS232 output, because all have a onboard TTL to USB converter. The converter on this specific engine board is the PL2303 which converts the TTL v.24 output to USB Bridge, you can grab the datasheet is here now... we cant use a low level TTL/CMOS signal for anything, we need to convert that to a proper RS232 level
NOTE : RS232 is the electrical specification, V.24 is the protocol specification
Here's where your old mobile cable comes into the picture, you need to connect the INPUT TX/RX from the GPS to that RS232 converter and then connect it to your XDA, see the pictures below
Since the GPS now is not powered by the USB any longer I used the power from the XDA connector as you can see on some of the pictures. BE aware that the RS232 converter also is powered from the +5V which is given to the XDA. Works for me without any problems at all.
The cable I found was using the Sipex SP385A RS232 SOIP chip, datasheet is here
Heres the PL2303 TTL to USB Bridge module PL2303 on the GPS engine board
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Heres the RS232 converter from a old mobile phone cable
Heres a view of the thing before assembly, note that I opted in for keeping the DB9 connector, just in case I wanted to use it on my laptop in the future, I could also have keept the USB connection, but too many cables in that cramped space. On the picture you see the the right the old mobile cable I used for RS232 conversion in order for the TTL v.24 from the GPS to get a proper RS232 level, the middle the engine board, and left the antenna and XDA connector
And here is the finished unit, working on my good ole SX-56
And here a datasheet for the Circom Gmouse engine board
Enjoy the tinkering, I had fun doing this. If you have any further question, feel free to ask, and I'll answer to the best of my ability's. And please note duh, I do not take whatever responsebillity for what you do to either your GPS or XDA.
Regards

[Q] Mesmerize USB port problems. Alt PCB points for USB? anyone?

Does anyone know ANYONE that knows another spot on the Circuit board that I can pick up USB at? My issues is that the micro usb port was damaged. The pads ripped off the pcb and most of the traces. I tried removing the enamel from the PCB to get a solder point for data + and data - but to no avail. If anyone can explain or show me pictures where else on the board I might be able to get the 4 USB points at I would be ever grateful. I'm boot looped AOPK 29, can't get into clockwork recovery mode. Download mode works..but the PC doesn't even see the phone(not at all..not a driver issues 100% sure). If I can get the USB running..I can flash it back to operating condition. At that point I can manage to solder on a new micro usb port and get to the +5v and -5v so I can charge the thing. As I mentioned before its the + and - data signal I can't get. So even if you can point out where to get a hold of those that would fix me too. I can solder pretty small.
Or anyone forum where you have a feeling someone might have an answer or would be kind enough to look at a high res picture of the PCB and help me trace it. I love my mesmerize to death. I'd really hate to see it die like this..It might be "legacy" But it'll post over 2500 quadrant and runs fast and smooth.
Thanks in advance.
Arick - AKA Gigaah

Gigaah said:
Does anyone know ANYONE that knows another spot on the Circuit board that I can pick up USB at? My issues is that the micro usb port was damaged. The pads ripped off the pcb and most of the traces. I tried removing the enamel from the PCB to get a solder point for data + and data - but to no avail. If anyone can explain or show me pictures where else on the board I might be able to get the 4 USB points at I would be ever grateful. I'm boot looped AOPK 29, can't get into clockwork recovery mode. Download mode works..but the PC doesn't even see the phone(not at all..not a driver issues 100% sure). If I can get the USB running..I can flash it back to operating condition. At that point I can manage to solder on a new micro usb port and get to the +5v and -5v so I can charge the thing. As I mentioned before its the + and - data signal I can't get. So even if you can point out where to get a hold of those that would fix me too. I can solder pretty small.
Or anyone forum where you have a feeling someone might have an answer or would be kind enough to look at a high res picture of the PCB and help me trace it.
Click to expand...
Click to collapse
The data points are on the back of the board maybe this pic will help you
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Perfect! Thanks a lot.Now to muster enough soldering skill to hit those and not wreck things.

I think I want a usb Female to Felame - but not sure.

Hi all,
got a bit of an odd one for you all to ponder over. I recently purchased a magnetic charging cable. One of these
http://www.ebay.co.uk/itm/201496892947?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
It has a very small adapter that plugs in and lives in the micro usb slot on my note 3. The cable end then attaches magnetically and away we go - charge and data - pull and it drops off. Pure magic.
The pondererance is how do I connect OTG devices? This adapter is a snug fit and designed to stay put. For socket damage I would also prefer it stay that way. The lead goes to a normal USB male. So to connect I think I need a usb Female to Female - such a thing does exist here
http://www.ebay.co.uk/itm/2-x-USB-2...515514?hash=item20cfdff93a:g:~9kAAOxy4t1Sf0rr
but I am unsure what is wired to what - and indeed what should be wired to what... So
1) is this the right thing - plug the magnetic lead into it then plug a USB pen in to the other end and away we go?
2) if not how should a female to female be wired? I have plenty of usb extension leads and am willing to cut a pair of them to make the appropriate adapter?
3) if there are no definitive answers how safe do you think it will be to try? I am thinking get the one from e-bay and then plug in a usb pen. Best case it just works, bad is the power is wrong and it kills the pen (upsetting but I can live with it). Worst case it blows up the phone. What chances do people think for just working or damaging stuff?
Open to any and all thoughts and suggestions...
Keverso

Personally, I would give it a try - learning by doing. But I think the chances are not quite high that it will actually work.
Here is a scheme of the difference between OTG and regular USB.
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Sounds good. Looking forward to it.

alphatact1cs said:
Personally, I would give it a try - learning by doing. But I think the chances are not quite high that it will actually work.
Here is a scheme of the difference between OTG and regular USB.
Click to expand...
Click to collapse
So - if I am reading this correct I take two extension leads - cut the female ends and join each colour to the same on the other lead (assuming both leads have the same colour code) and that should (with a little luck) work? That sounds easy enough. I am obviously worried about killing something but I have got an old galaxy 1 phone kicking about somewhere as well as a usb pen I would not be too upset to lose. I may well give it a shot this weekend and see what happens... I will report back if I do.
Thanks for the help.
Keverso

help - Battery connector on S6 Edge main board

Hi, I could use a bit of help, if possible. My phone (S6 Edge) went into salt water and then quickly died. My goal at this point is to hack the phone back to life just long enough to do one final backup. At this point I have disassembled the phone and cleaned the salt residue off the board with a soft toothbrush and alcohol.
Here's a picture of the main board where the battery attaches. It appears that the saltwater created a short here and essentially melted the power connector. The battery connector (not shown) is similarly destroyed.
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My assumption is that there are normally 4 circuits between the main board and the battery:
1) +3.85V
2) GND
3) Temp sense (thermister?)
4) Temp sense
Unfortunately it's hard for me to tell what goes where because both connectors are so badly destroyed, but here is my guess:
What I'd like to try (nothing to lose at this point) is to wire up these four circuits and bring them out to a lab bench power supply and perhaps a resistor to emulate the temperature sense.
Questions:
a) Are my assumptions on +/- voltage connections correct?
b) Does the phone require a completed circuit on the temp sense pair?
c) If so, what is the nominal value of resistance on the temp sense pair?
Thanks to anyone who may have mapped out this part of this board....
Bryan

You are right about the PWR pins - GND is thermally relieved from GND polygon. The other thick track or 'region' should be battery voltage.
Somehow I doubt that both thin tracks are used for temp. sensing, unless it's a differential signal. You can test this with a 2 channel oscilloscope, provided that you have a working battery.
Either way, if temp. sensing won't work, everything else should. Try hooking it up to a power supply. 3.8 to 4 volts shuld do just fine. The thing is that (and you are probably aware of this) electronics don't work well with salt water Especially ones with batteries in it. Chances are that one or more chips are fried, in which case.. well, you get it... Even if chips are fine, the solder joints are most likely corroded, which means that not all pins are electrically connected to the pcb.
If the data is really important to you, you might be able to desolder the nand flash and resolder it on a working motherboard. BUT! I have no idea if this would actually work - just a wild guess. Also, there is always a chance to overheat the chip.
If you're skilled enough with electronics and programming, you could try and look up the datasheet of the nand. From there you could try and figure out how to read raw data off of it. If you do, you might be able to build a device for reading the nand directly and storing the data wherever. Not particularly handy for a one time use, but would make for a fun project ^^

Add external antenna port to modern cell phone

Hey guys, have a hardware puzzle I need to solve. I want an external antenna jack for a modern phone for the purpose of moving the rf away from user and improve signal. For years we have happily used our Samsung S4's for this but verizon just notified us the infrastructure they used will go off in 22.
Pictured below is the the ports on S4 and wilson adapter to external antenna.
The S4 will use its own antenna then switch to the external when plugged in.
I read somewhere that these ports were for testing, any of you know if this circuit still exists in new phones?
I am hoping that these "test" ports still exist in new phones and can be spliced into or plugged into and pig tailed out of the case.
Can any of you hardware engineers point me in a direction? Have not found much promise with custom builders yet if you know any.
Yes I have seen the passive patch leads/cradles, my mission is mainly to move the signal away from the user. This needs to be an option for rural customers anyway to just plug in external antenna as you lower DB's much more than the boosters ect.
thank you much for your expertise and time.
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Never knew that was there. Cool. Looks like my old S4+ is DOA too.
Why not just use a wireless booster?
They use them a lot in W Texas
Guess you're in for some future shock... I went from the S4+ to the Note 10+. Lol, that took some readjustment and a bit of a learning curve.
However I'm less than enthusiastic about the Samsung flagships since the N10+ as well Android 11 and up. Scoped storage* and forced encryption* are fully active on 11 and 12.
I have a N10+ running on Android 10 (as well as this which is running on 9) they both run well, fast and stable. The one running on Android 10 has dozens of new Samsung system apps in order to retain its functionality. Both look and run nearly identically. I want that level of functionality... I won't upgrade past 10.
With 11 maybe, with 12 you're in for a rough ride.
*both use more cpu cycles, resources and make using the phone much more convoluted. Most older apps will not run on 12, and maybe not 11.
Some overlay apps don't run on 10 and up, however in 10 scoped storage is not fully enabled.

Thank you blackhawk, I was wondering what the newer operating systems would permit, not all progress is forward. I see most have gone away from a headphone jack! I hope someone can point me in a direction to add an antenna jack.

pictured is the S4's external antenna ports L1 and R1 the smaller connectors are the phones internal antenna. The phone is able to shift back and forth between external and internal antennas. Anybody familiar with this circuit? What was the manufacturers intent with L1 and R1? I have heard they were used for testiing.

Here is google pixel 3a with black and white antenna coaxial circled and two other connectors squared. What are the connectors in the boxes for? How does this circuit work? Anybody work on this stuff or know someone who would?