External antenna for the radio - iPAQ rw6828, XDA Atom General

Hi all great forum
I am going to make an external antenna for the radio in the atom , i know the headphones are the antenna when plugged in but i dont want to lug them around
i use the speakers to listen to the radio so... i would like to know which pin on the headphone jack is the antenna and is it the switch in the jack that tells the o2 that headphones are plugged in or does it sense the resistance of the headphones
i am just going to cut a piece of real fine wire at 1/4 wavelength and coil it up inside the cover i use

I was thinking of doing it too.
Well ... thats an idea I've been toying with too . . haven't got round to it but I guess its a process of elimination .... have pinouts from the plug and connect the wire to each in turn and see which gives best reception.
if it is a looped antennae then you need to connect to 2 pins ... this risks shorting out your atom circuitry .... a good way to avoid this is to use a Multimeter to test the included headphones and determine which pins are connected and which is not to avoid frying your circuits.
Good luck !
P.S. I'd be interested to know the results ....

Headphone(one of two) must be included in circuit of antenna or length of wire must be long.
lambda(length of wave) = f (frequency) / c (velocity of light) = 10^8(100 MHz) / 3*10^8(m/s) = 3 meters
Length of antenna may be lamda, lambda/n, where n = 2 or 4 (usually).
It's for information
Wire of antenna connects to one of signal pins: left or right channel in output for headphones.

i use the speakers to listen
Click to expand...
Click to collapse
you can use speakers while headphone is plugged in. actually you don't need additional anthena.

Related

Handsfree connector wiring - anyone?

I'm trying to modify a broken handsfree set into a headphone adaptor which leaves the builtin mic active, but I have trouble getting the wiring right.
Does anyone know which color wire is which inside the headphone cable?
I checked at http://wiki.xda-developers.com/wiki/Connectors, but I have 6 (!) wires in my cable, and the description only lists 4.
I suspect the two copper wires (one in each cable) are both GND and can be connected toghether. But then, I still have one too much, a green one.
I scraped off some isolation on the wires and twisted them together with the wires from one of the earpieces (i tried both), but however I do I can't get any sound!
I have another headset, so I know the jack is still working.
Does anyone have a clue?
Thanks!
Anyone?
This may help. I removed the ear phones supplied with the XDA and added a female connector. Now I can use any 3.5mm earphone set, and the handsfree mike.
I found the instructions here...
http://www.tekguru.co.uk/phpBB2/kb....ighlight=modifying+making+headphone+connector
Copper goes to earth, red is right channel and green is left channel for sterio.
Hope this helps

mp3 earphone adapter

hi,
does anyone know if there is anyone else other then pc mobile that sells the mp3 player earphone adapters for the xda2?
i am on my 2nd adapter from pc mobile and its already broken after 3 weeks of moderate use. the 1st adapter broke in the same way. the connection just breaks inside the wire. at the moment you can still move the wire around so you get sound out of both earphones but its only a matter of time before the one channel dies completely. im going to email pc mobile and see what they can offer me for 3rd adapter. or i may just buy it from someone else if i can find another one.
its been really disapointing with pc mobile so far. i bought the mini sync cable and the earphone adapter from them not too long ago. of course the mini sync cable didnt work and the earphone adapter went a couple weeks later. they sent me a replacement and now my 2nd adapter is dying
any suggestions?
As a soon to be XDA2 user who wants to play MP3s with it, may I ask you to elaborate on this earphone adapter thing? Do I need to buy an adapter before I can use my XDA as a music player? Or is that just if you want to use normal earphones? I know that most mobile devices use the handsfree headset socket for listening to music
What he means is that for some (incredibly stupid, imho) reason HTC decided to use a 2.5mm audio socket on the Xda II when every pair of half decent earphones you buy all have 3.5mm jacks. I know they probably did this to save some space inside the unit but im sure they could have managed 3.5mm socket.
Anyway this means if you want to use decent phones instead of the crap that comes with the device you will have to shell out for an adapter to go from a 3.5mm jack to a 2.5mm jack. But remember in doing this you will lose the headset function of the default phones.
not with this one
http://pc-mobile.net/pxdaa.htm
but the buttons dont work with xda2
Ah that's okay then, coz my P800 is already like that. You just have to use a handsfree kit instead of normal headphones.
Would Maplin sell them?
if you mean a 2.5mm to 3.55mm converter ?
http://www.google.dk/search?q=2.5mm+to+3.5mm+jack+converter&ie=UTF-8&hl=da&btnG=Google-søgning
have no idea who or what Maplin is though
2.5 mm jack
hi guys
would it not be easyer to just cut the end off your headphones and soilder a 2.5mm jack on it?
http://www.maplin.co.uk/
maplin do them 56p :?
sorry 84p
Exactly my idea... Or buy a handfull of regular black Nokia 8110 headsets, cut off the jack and solder a 3,5 mm bus on it !
You need <Blanc> for Ground, and Red and Blue wire for audio...
<edit>
Sorry, my mistake !!
If you cut the nokia plug of a headset you get:
<Blanc> = Ground
RED = Mic
Green = Audio-R
Blue = Audio-L
For who's interested, the wireing on the mic+earpiece-end you are left with :
<Blanc> = Ground Mic
RED = Ground Audio
Green = Mic
Blue = Audio
so if you want to re-wire a Nokia (compatible) Headset ; swap red to green on the headset-side, and connect the leftover RED from the headset-side to the <blanc> on the plugside.
I paid £3 for a mini converter cable off ebay and it does exactly as described, use it in the car with tape adaptor
I have opened up the mic/switch unit to solder on my Sony headphones in place of the original XDA II ones.
It's a fairly simple process and will be a nice job when it's done.
The problem is the Sony wires are varnished so I can't get the solder to 'stick'.
Does anyone have any idea how to remove the varnish?
Heat doesn't do it and scraping it off is not really an option as the wires are too fragile.
Thanks in anticipation.
I was considering doing the same thing with my foldable Sony's, but have been chicken to do so, so far...
Have you considered nail polish remover or paint thinner to take off the varnish?
Yes, just after I hit the submit button the idea of nail polish remover hit me. I'll try it as soon as I get back to the UK. I'm in LA at the moment.
I'd recommend it. It makes for a really neat solution and, apart from removing the varnish, is really easy to do.
When I'm done I'll post some pictures.
Sorry, my mistake !!
If you cut the nokia plug of a headset you get:
<Blanc> = Ground
RED = Mic
Green = Audio-R
Blue = Audio-L
For who's interested, the wireing on the mic+earpiece-end you are left with :
<Blanc> = Ground Mic
RED = Ground Audio
Green = Mic
Blue = Audio
so if you want to re-wire a Nokia (compatible) Headset ; swap red to green on the headset-side, and connect the leftover RED from the headset-side to the <blanc> on the plugside

Possible Car Kit breakthrough!

I am 99% finished on developing a car kit for the XDAIIs. The plan is to make this available for all versions of XDA, MDA, SPV etc. when complete.
At the moment the kit will do the following
Power the XDA
Has got a microphone input.
Has got speaker output of voice through the car stereo speakers
Has got speaker output of navigation through the car speakers
Connects to a wired GPS antenna - currently using PS2 connector but I'll be making an RJ11 version on Monday!
All I need now is a way of signaling to the car kit that the XDA is in the holder! :x
From the car kit, I have 1 wire which needs to be connected to 5v to power on. I also have a 5v feed from the car kit so I could simply join the wires but thats not the point.
I would like to find either of the following options.
1 - 5v feed from the XDA when in the holder
2 - Using 2 pins on the XDA to feed 5v in and get 5v out on another pin.
I have also found that on an XDAII, there is a 5v feed on one pin when in a call, but there isn't anything out of an XDAIIs in the same situation. I just need 5v when the device is present in the holder.
If anyone can tell me if this is possible I would really appreciate it.
Regards
...Spence
In order to get the carkit to work, I think you had to ground the pin instead of putting 5V to it, as specified in this thread :
http://forum.xda-developers.com/viewtopic.php?t=4829&start=75
It would be great if you could post your circuit !
Where did you get a proper connector, or did you just modify a xda II connector ?
Ciaos,
Kristof
A modified Carcomm cradle?
THe XDA uses 3 pins for the +5 Volt charger. I believe these pins are shorted inside the XDA
If you charge through 2 of these pins you might be able to use third to recognize that the XDA is inserted
s93ncer said:
I have also found that on an XDAII, there is a 5v feed on one pin when in a call, ....
Click to expand...
Click to collapse
What pin is that that gives +5V when in a call on the XDAII?
What pin is that that gives +5V when in a call on the XDAII?
Click to expand...
Click to collapse
Pin 12 on an XDAII goes to a positive voltage when in a call.
One thing I did notice was that the voltage does just appear and disappear, it builds up and drops off over 2 seconds,
Regards
...Spence
Thanks for the info!
Is there any similar behaviour when ending a phone call
I suspect my XDAII/iMate carkit is triggered by this signal, I would like to manipulate it in order to have the carkit amplify the TomTom directions also.
Other question: what type of mic did you use? The XDAII has quite some problems with the mic input signal (resulting is bad sound quality)
The voltage builds up to about 5v when making a call and does drop off to 0 when you end the call. Also, I don't have any problems with sound quality (although this is in an office at the moment) with the microphone.
I am using a universal car kit that my company sells, just hacked the connector off the end and connected it to the XDAIIs connector.
Still having problems, but with the car kit now and not the XDA
Can't get it to switch on/off when the XDA is in the holder and taken out!
..Spence
Sounds like you've found out some good stuff Spence.
I'm working on a similar project at the moment, except I'm using a circuit that detects audio coming from the XDA's pins, which then switches a relay to ground.. this is connected to the car stereo which goes to "Telephone mode" when grounded. Its about half way done at the moment, so I'm not sure how sucessfull its going to be.. but I'm currently having trouble with the volume of the audio from the XDA, (I haven't tried a Mic on it yet)
Would be interested to know if the XDA1 also has 5v on Pin12 when in call.. as I could revert to this if my plan doesn't work, although it would mean loosing Tomtom prompts through the stereo
Keep us updated on your progress :wink:
The other added goodie that I can put into some vehicles is a thing called an intellimute - made and designed by my company!
Linked in with the stereo, it will mute the stereo when it senses audio not just when in a call hence the Nav audio as well.
This might be useful to you - but you will probably have to but one to try it out.
I don't have an XDAI to try anything with - plus most people who I have spoken to have a II or IIs
...Spence
@swifty: When Pin 19 - Car On - is connected to GND via a 10k resistor the XDA gets into 'carkit-mode' resulting in ALL audio to be sent via the bottom connector. This will help you feed the audio to your stereo.
Together with the Pin 12 behaviour (+5V when in call) one should be able to build a carkit circuit:
Connect the audio-out pins to the car-stereo audio in or -alternatively- a seperate amplifier.
Make your car stereo go into mute when Pin12 gets 'high'
BTW, I gues you checked the wiki pages:
http://wiki.xda-developers.com/index.php?pagename=Connectors
I would like to know what mic type is used by you guys, as I read in the other thread mentioned that this still might have issues.
Thanks Edsub,
Thats pretty much how i've got it hooked up at the moment, but I think there was a problem with the amplifier I was using as the audio from the stereo was very quiet. I've now changed the circuit and will be testing it out in the car tomorrow.
Spencer
What connector and cable are you using for this.
Thanks
What connector and cable are you using for this.
Click to expand...
Click to collapse
To cut a long story short, I had a couple of data cables for Ipaq's (3800 I think) lying around and I got a complete car kit from stock, cut the cable off at the phone cradle end and soldered on the connector from the Ipaq.
At the moment it looks a real mess, but it does work!
Haven't played with it for a few days, but might do some more today.
FYI, the problems at the moment are car kit related, not XDA - the XDA issues are solved.
...Spence
If you need an xda 1 and or the car kit to loan for your project, let me know.
I still have my iMate/XDA2 carkit (the one as sold by ie Expansys).
There still are two things I like to change:
1. Mic quality. I allready used a better mic (Nokia style gooseneck) with a thicker wire (as sugested by Expansys): Things did improve, but I still sound like I have a bag over my head (or like I am talking into a toilet bowl according to my collegue) . . .Any help greatly appreciated
2. Only the in-call audio is send to the carkit speaker. I would like to get all audio on the carkit speaker (so I get better amplified TomTom instructions). The car-audio mute only has to do its work when in a call (otherwise you wont be able to listen normally to a conversation or ie. the traffic info on the radio)..also: any clues???
A hint: In one of the other threads on this it is suggested that putting someting into the XDAII headset jack wil get all audio out, but that is not quite workable withou drilling the cradle to pieces.
Can anyone tell me what the effect on the bottom connector signals is when you insert something (ie an empty plug) in the headset jack?
Hi all.
Great topic. There's one thing I still don't know.
Does IN_CALL pin work in XDA 2s / MDA III ?
Mine XDA IIs doesn't put anything on IN_CALL pin when calling.
I have been having similar problems with audio with powered cradles/car kits. Just cannot get the damned audio to come out of the car kit, only call audio! (XDAIIi/Qtek 2020i)
http://forum.xda-developers.com/viewtopic.php?t=41716&highlight=
http://forum.xda-developers.com/viewtopic.php?t=45779&highlight=
http://forum.xda-developers.com/viewtopic.php?t=45462&highlight=
Suggestion
Why not simply have a mini contact switch in the bottom of the cradle to sense when the phone is in the cradle?, or use a simple current sensing circuit?
a VERY simple circuit would be a coil of the 5v feed and a reed switch, when current is being drawn through the coil it will generate a weak magnetic field, which could be used to close the reed switch...
Simple yet effective...

Audio (MP3) through original Dockingstation. HELP!

Hi,
I'm only 13 and a proud owner of an O2 XDA 2.
This I what I need help with.
I would like to place my USB docking station on top of my subwoofer, and connect my XDA with it (only for audio purposes only).
I've read some of the forums here, but didn't find much info. :?
Could someone tell me which pins, on the connector, on the dockingstation send the sound? I would like to add 2 cinch cables to these pins, and attach them to my subwoofer (to kind of make my XDA like an Ipod or another MP3 player, where I simply stick it into my dockingstation and start playing MP3s through my sound system).
Thanks,
Kind Regards,
Tony Schattat
Hi mate.
Note sure you could connect the XDA directly to a speaker as I doubt it would have the required power output (but I don't know much about this, just being logical).
Take a look at the following thread: http://forum.xda-developers.com/viewtopic.php?t=26489&highlight=
This guy has basically modified the headset to have a 3.5mm jack - I've then suggested (and intend on doing this) that you could put 2 standard audio outputs instead.
On reflection though, I think his suggestion may be better as it reduces the number of leads. If you then needed to split the sound out to 2 seperate channels you could use something like this:
http://www.maplin.co.uk/Module.aspx?ModuleNo=43086&doy=3m9
Cheers
Wayne
Hi Wayne,
Thanks for your reply.
I would rather like to have a solution which is built in my dockingstation.
With alot of precision I was able to do the following.
1. Used http://wiki.xda-developers.com/wiki/Connectors for details.
2. On pin 19 on the dockingstation I placed a 10K SMD resistor (as the standard ones are too big), connected to GND, as stated in the text.
3. Using a double cinch cable I soldered them onto pins 3 (CAR_AUDIO_R) and 4 (CAR_AUDIO_L), and both GND wires to GND.
But nothing seems to work.
I used the ohm-metre to check if the 10K resistance even came up to pin 19 of the dockingstation. I does. Unfortunately the XDA doesn't turn off it's built-in speaker and microphone, as stated in the text.
This basically simulates a car-kit for the XDA, doesn't it?
Kind regards,
Tony Schattat
Audio playback
Hiya!
Well if yer are 13 then it seems UK Schools are way behind German ones if they're teaching you about using Ohm Meters, Resistors and electronic theory already!
Ok, overall to me this whole precision soldering and resistor checking etc is all overkill for what you ultimately seem to want to achieve.
I've just bought off eBay the little 2.5 mm to 3.5mm standard headphone jack converter lead for about £2.50. I'm going to go nip into a shop or again off eBay and get a 3.5mm stereo to 2 phono plug convertor lead.
Simple case of then slapping that into the Aux input of my Hi-Fi amplifier, or my mini deck hifi etc and playing the mp3's through that!
No need for faffing around with soldering irons, and electronic theory and all that!
Added benefit is of course that through the hifi unit, I have full control over the audio equaliser functions and so will have the full spectrum of audio frequencies to hear the music - Your requirements states you just want to connect it to a subwoofer. Low frequencies are great, but you do need the upper frequencies too!
That will all set you back the grand total of about £5, and i've assumed you do have some audio equipment with an Aux input!
For 'constant' playback, when yer battery gets flat,... just plug the charger in!
Another benefit is that you can take the leads with you on your travels and setup the same at any of your friends houses with minimal effort!
I don't see the point of the route you are wishing to take - unless I'm missing something (I got in at 7am this morning after clubbing and up at midday, so im knackered!)
Cheers!
Hope this helps!
Dennis! West London UK!
Hi Dennis,
Well the schools here aren't all that far ahead ( I think, because I`ve lived in Australia for 6 years)!
It runs in the family!
I was able to find some handy info on some dockingstations on google, but I'm not very sure.
Is it true that the serial dockingstations have an audio connector on the rear side, opposite of the power connector?
Is the audio connector on the dockingstation the same thing as the one, which is found at the bottom of the XDA (would it disable the built in mic and speaker of the XDA and send the audio through connector on the back)?
If this is true, could I simply attach a 2,5mm to 3,5mm converter to the back of the dockingstation and attach the converter to my subwoofer?
Kind regards,
Tony Schattat
Audio playback
Hi there Tony
I'm still not sure exactly why you want to connect your USB cradle to play music through.... seems pointless to me..
The method I described would be the easiest for you to 'amplify' the audio output from the XDA2.
I may be wrong but I dont think the USB cradles have an 'audio output' connector at the back, it's a bit pointless as these devices aren't devised as 'audio players' - so no, you cannot put the 2.5 to 3.5 mm converter on and then connect that to your subwoofer (signal is wayyy wayyy too small to drive a sub woofer) if there is an audio output at trhe back of the usb cradle, then I never knew about it!! and same again, you cannot connect directly to a sub woofer.
Out of the socket at the bottom of the xda2 in a 2.5mm size, is an audio jack. Get the converter to take that 2.5 mm and output it to a standard 3.5mm headphone socket size. Right, at this stage you can connect 'Hifi' headphones and enjoy your MP3's that way. If you now want your music 'louder' you need to convert that (now) 3.5mm output to be able to connect it to some audio equipment that can 'amplify' the signal and play through some loudspeakers (the 3.5mm socket to Phono converter lead). That will go to your hifi amplifier in turn to which 'full range'loudspeakers are connected. You mention 'sub woofer' .. You could then attach your sub woofer to the amplifier and you will only hear the low 'rumble' of the bass frequency content of the music (again, a bit pointless!). If that's what you want then at this point all will work but then what's your plan for hearing the mid range and high frequency elements of the music?
I'm just thinking that for your final 'aim' (to hear MP3 files on the xda through loudspeakers) the method you are using is cumbersome, time consuming and pointless when you can have a 'full range' output using the method I described.
Take a look at eBay for the connectors - and you'll find you should be hearing music in no time!
Cheers! Dennis! West London UK!

Shift Trick: How to make mic work with headsets.

Original post:
ChipNt said:
Hello everybody. Actually the idea is a bit rubish as you need to open ur own shift and u must know what exacly ur doing. the headset`s stereo jack enters in a small socket, well inside that socket is a small connector for each line (2 sound +1 mic) wich will disconnect the onboard mic and spearkers all u have to do is to solder a small wire between all the 3 points of the mic. Find a service to do it if u dont know how.
Results: the onboard mic will work even if u plugin or not headsets.
Click to expand...
Click to collapse
EDITED: I opened and spent 20 mins checking each connection on mainboard and results are NEGATIVE. dont try this home. thank you
Example of a Similar connector
http://hackaday.com/2008/10/13/parts-35mm-stereo-audio-jacks/
Wow , major discovery ! congrats to u , but hv u tried it yrself first ? how well does it work pls ? i will only try dismantel my shift if it was proven that it can be done with yr style , but many thks for sharing anyway , cheers bro - jimmunsw
I used to do and repair electronic devices somewhere between 10 and 15 years ago, that jack functions the same way even today, is the cheapest and easier way to trigger and disconnect main speakers and mic when headset is plugged in. its the mini jack socket used everywhere and if i see a photo of mainboard where this jack is connected; on both sides i can tell you exacly wich is pin 1 3 5 paired with 2 4 6 or 7 8 9, and one more for the ground to confirm my version it must be 9+1 pins of this connection on the mainboard.
in the link above u see an example of a standard socket for x3 jack headset while htc socket seems to have x4 headset 1 for mic 2 for stereo + 1 for ground
http://images.google.com/imgres?img...&sa=N&start=63&um=1&ei=-7EVS5O2KdCd4QbskvTLBQ
please see also http://en.wikipedia.org/wiki/TRS_connector , anyone can atach a photo of the htc mainboard with the best zoom possible to the jack socket pins on both sides?
I thought this to be the case thank you for the imput I am willing to give this a go myself and confirm or deny weather it works this friday so check back in with me on saturday
To enable external mike for phone functions
Is there a similar amateur rewiring that would disable the onboard mike and enable an external mike for phone calls on the SnapVue side?
cybericebyte said:
I thought this to be the case thank you for the imput I am willing to give this a go myself and confirm or deny weather it works this friday so check back in with me on saturday
Click to expand...
Click to collapse
cybericebyte Please atach photos of the mainboard zoomed with the jack section both side, my pc is in waranty cant break my heart opening it yet
Sheepster said:
Is there a similar amateur rewiring that would disable the onboard mike and enable an external mike for phone calls on the SnapVue side?
Click to expand...
Click to collapse
I am afraid that u cant as near the mic u have some small other things near ur external mic like a button to answer calls wich should be detected by a software or a volume control. i need to buy one more htc headset to open it. but at least the onboard mic could work when u plugin headsets that might be very cool inside cars
i will see what i can do as fars as pic i dont really have a good camera
bad news, read first post. thank you
If we would be able to attach a bluetooth to the mainboard ....
ChipNt said:
Original post:
EDITED: I opened and spent 20 mins checking each connection on mainboard and results are NEGATIVE. dont try this home. thank you
Click to expand...
Click to collapse
what were your full findings?
Results are:
By measuring the ohms on the htc headset i figured out that first 2 pins are the left and right headset and the mic is third right near the ground.
For the analogic swich that i was talking about on 3+1(ground) it means that on motherboard the trs socket shouldve have 6 + 1 pins soldered (a pair of 2 for wich swiches the headset and one more pair for the mic + 1 the ground) while on the shift motherboard i saw only 4+1 wich means that the headsets are the only ones disconnected => mic d/c is digitally swiched.
Ps: I hope im not wrong, last time i did an electronic repair was like 11 years ago
i'm not so sure about this i did some real minor testing with the headset mic only partialy pluged in and my voice through the headset mic was picked up so actualy i belive that the mic is wired to the headset jack but through the left and right speakers but again i am not sure of this wiring
Another ideea
Another idea that i got from someone who still works on fixing phones, soldering etc is that the lastest jumper is a "releu" a small piece of hardware wich disconnects or connects a set of circuits eq: microphone + the stereo line, based on a triger eq: a connector wich exists at the end of the socket jack, and the other pins of the sockets seems to be the sound and the mic from the headsets
someone really needs to do investigations on this, we are just few steps away
cybericebyte said:
i'm not so sure about this i did some real minor testing with the headset mic only partialy pluged in and my voice through the headset mic was picked up so actualy i belive that the mic is wired to the headset jack but through the left and right speakers but again i am not sure of this wiring
Click to expand...
Click to collapse
I can confirm this! I used the HTC headset and left the last ring of the plug (GND?) outside of the socket and mic was working in Notes! (But the speakers are still enabled -.-)
Regards,
Sven

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