This message contains all postings in this thread
dated before January 19th 2003
Subject: Car kit creation issues
From: Carlos
Date: 24 Dec, 2002 22:09:25
So I'm in the process of making a full car kit for the XDA. My
goal is to provide power, serial (for GPS), and sound in/out.
I've conquered the physical part by hacking up a cradle, which
will be mounted in the car. That was more complex than it
seems. Not particularly complicated, but required work.
For the electronics, "plan A" was to simply wire the output to
the car radio and attach a standard microphone for input.
However, it appears that the microphone input requires a high
level signal. I did not get any input at all from a microphone
(yes, tested more than one). I was only able to get input by
connecting another audio device's headphone connector directly
to pin 1/Mic In, and then it wasn't as loud as I would have
expected.
Also, the sound ouput via the bottom connector is quite tinny
and faint compared to the headset output. At least, it is when
listening via headphones; maybe headphones are too low-impedance
for that output.
Hmm, ok, it does seem to be an impedance issue. When I ran that
output to a cassette adapter it sounded fine, and actually
louder than the cassette adapter plugged into the headset jack.
Ok, that's good.
So I tried "plan B"--connecting it to an existing Ericsson car
kit. However, the Ericsson's kit's electronics apparently come
from the Bizarro world. I was unable to figure out how a phone
tells the kit that there is a call and to activate itself.
There are two wires fron the Ericsson unit which do this, but
nothing seems to change with them. They keep the same voltage
and resistance whether a call is on or not. Weird.
Plan C...the only other thing I can think of is to get a
microphone to boost the input. I hesitate doing this because
I'm thinking that echo will be a problem, which is why I was
considering using the Ericsson kit anyway--excellent noise
cancellation. It appears that even a universal kit would be
unusable with this device because I don't believe they boost the
microphone at all.
Anybody got other ideas?
Subject: Audio input problem
From: XDA developers
Date: 26 Dec, 2002 12:06:52
The audio-input needs to have absolutely no DC bias. Coupling
the audio in through a 30 pF capacitor should do the trick.
Subject: ?
From: Carlos
Date: 26 Dec, 2002 18:56:25
The problem is not on the input side, other than the level
having to be high. A cap won't solve that since a microphone
has no DC output. I can get it to work just fine from higher
level inputs.
Related
Does anybody know:
Is it possible to connect my car speakers to the O2 XDA Carkit directly ?
Marcel
Nah, not enough power. You need your car stereo as an amplifier. Alternatively, you can buy car amlifiers which are only amplifiers, but then make sure you don't end up buying a so-called 'booster', because it is meant to amplify a signal which is already at speaker level even further, for those that have sacrificed all space in their trunks for sub-sub-sub woofers and other tools for terrorizing their fellow humans.
You could try a £10 maplin cassette adapter, http://www.maplin.co.uk spliced onto a o2 xda headphone cable. You can use the nokia adapter version straight from the box, as the connector is the same size, but it is mono. Hence why I adapted a spare xda headset instead, as I thought the button on the mic pod might be useful, not to mention portable between different cars.
However, I have had problems with "transmit" noise using this "lash up" method. So its not perfect, but to be honest if you want music playback or tom tom navigator audio output its excellent.
Does anyone know if the external amp/back input of a hifi would stop the reception of the transmission noise during a call/gprs exchange. I'm using an old crappy car stereo without a seperate input, and the car is probably worth less than the xda as well! hence the cassette adapter method. :wink:
The MP3/Headset Audio Adapter from the other thread may be a solution?
It's a O2 Carkit with 2 outgoing speaker cables.
If i connect it directly to the cables that are coming from my car radio, will that work or will it blow up my xda.
http://www.pocketpc-club.nl/content.php?id=1275[/url]
it works through a standard nokia car radio relay kit
it works through the nokia car radio kit that was already in my car with my nokia phone, I simply plugged the radio relay kit intop the speaker socket of the O2 car kit and joined the yellow mute wires together.
I have recently accuired the TomTom Navagator 2 software and am extremely pleased with it.
I do not currently have any car kit for making handsfree phone calls.
I have installed tha loud voice prompts so that the tomtom voice commands can be heard through the xda's speakers and im happy with this.
However compared to the loud voice prompts by the navigator software the handsfree audio available through the xdas speaker during a phone call is almost inaudiable over the road noise.
I therefore think im going to have to buy or build some handsfree.
My question is primarilly if im to use the car_audio_r and car _audio_l pins to output audio does all audio output through these pins or only phone audio. ie will i also hear the navigator voice prompts through my hands free (this is what i want)
Also Im wondering if it is possible to use the output from these pins to send audio to a car speaker without connecting an external mic and continueing to use the microfone built in to the xda during phone calls as know one has ever complained about not hearing me - i just cant hear them.
Thanks in advance for any help anyone can give - im sure somebody out there has played with this allready.
roycruse said:
My question is primarilly if im to use the car_audio_r and car _audio_l pins to output audio does all audio output through these pins or only phone audio. ie will i also hear the navigator voice prompts through my hands free (this is what i want)
Click to expand...
Click to collapse
All audio (phone and PDA) is output on these pins.
Also Im wondering if it is possible to use the output from these pins to send audio to a car speaker without connecting an external mic and continueing to use the microfone built in to the xda during phone calls as know one has ever complained about not hearing me - i just cant hear them.
Click to expand...
Click to collapse
As long as leave the CAR_ON# pin open (i.e. not connect it to ground or 5V), the microphone of the device is used.
As long as leave the CAR_ON# pin open (i.e. not connect it to ground or 5V), the microphone of the device is used.
Click to expand...
Click to collapse
Do you mean that internal microphone is used but all audio is still output to the car_audio_r and car _audio_l pins with the car_on# pin left open.
roycruse said:
Do you mean that internal microphone is used but all audio is still output to the car_audio_r and car _audio_l pins with the car_on# pin left open.
Click to expand...
Click to collapse
correct.
The soldering iron is warming up allready.
The soldering iron is warming up allready.
That sounds like exactly what i need - ill modify my tomtom cable to include the 2 new connectors then run an extra cable out of the 3 way connector on the tomtom lead to go to either my car stereo or a speaker amp mounted under the seat or something.
I dont know if my stereo in my car will except car phone input as its in the shop at the moment getting repaired so i cant take it out - but how do these things usually work - does a pin on the stereo side have to go +5 or GND for the car phone audio to replace the music or does it detect audio and automatically cut in over the music... excuse my ignorance car stereos and car kits are not in my realm of expertise.
If there is a pin that has to be made +5 or GND on steroes to know when the audio needs to be output can the xda handle this at all...
Usually car radios have a mute input to turn off or down the music when the phone needs the speakers. The XDA does not have such an output. You could fabricate something that detects audio and then for a preset time presents the right mute signal to the radio.
Always questions ask you do... Try and fail you must to learn!
Thanks for all your help. I'll start hacking at all my new kit as soon as possible...
I'm trying to wire my own car kits for XDA 1.
As there is no way i'm paying the prices asked for the proper car kits.
I already have an in-car holder with a connector fitted for my GPS, and I wish to solder in some more wires to link phone features in.
I've done some searching around the site and this is the info I've figured out so far..
Pin 1 for Microphone Input
Pins 3 & 4 for Audio Out
Pin 19 to tell XDA its in car mode
So my questions:
Are pins 2 & 5 the grounds for the Audio out ?
My car stereo has line inputs (phono connectors) can I just rig up these connectors to Pins 3 & 4 (with grounds) to get audio out ?
I have a phone mute wire on my stereo, what do I hook this upto, so that music will mute while in phone call / getting navigation instructions?
Thanks
Neil
Swifty said:
Are pins 2 & 5 the grounds for the Audio out ?
My car stereo has line inputs (phono connectors) can I just rig up these connectors to Pins 3 & 4 (with grounds) to get audio out ?
I have a phone mute wire on my stereo, what do I hook this upto, so that music will mute while in phone call / getting navigation instructions?
Click to expand...
Click to collapse
Take a look at http://www.xda-developers.com/connectors/
There you can find all about the connector. Ground is ground, so you can use Pin 2 & 5 for your Audio.
Telephone mute at your car stereo won´t work easy. There is no pin at the connector that is used when a phone call is getting in.
The original car kit does this in a black box, that mutes every time a signal comes from the xda.
Just search a bit in the forum....
HTH
Stefan
Thanks already had a look @ the connectors page, its very usefull.
I've done some more searching but there are still a few things needing a bit of clarification.
1. Do I need any capacitors or anything else in the line from XDA to Line In on my car stereo?
2. Could one of the audio out feeds be split to also give the mute signal. If so how could i convert it so that the feed is Ground when outputting, and live/dead when not ?
Cheers
Neil
Anyone ?
i have my audio out direct to my line in on my car stereo
i have a mono analog sound amplifier for the mic in (using a carkit mic)
you dont have to do this, just dont put pin 19 to ground, and audio will go through the line out of the connector as well. you can just speak and the mic is fine for xda1
xda2 is very different , had to rewire everything
just take 4 or 5 GND wires from the connector
bundel them to 1 GND and put it to the - of you car
Thanks mate,
Can I just check a couple of things to make sure I don't kill my XDA or my stereo
1 - Nothing is required inline with the audio out 2 line in cables, they just hook straight up ?
2 - Only connect Pin 19 to ground if I don't want to use the internal mike?
Can anyone recommend a small mike, I can fit in the car to use with this setup ?
Cheers for all your help :wink:
^ Up we go
a external mic is a lot off trouble to build in
i can tell you that
if i was u and got a xda1, i would nog ground pin 19
use the internal mic
yes, just hook gnd and line 3 and 4 (audio?) directly to you line in of your car stereo, i think its stereo dependend. its a analog stereo sound wich is produced by your xda1, i have a line in for gps or dvd player audio on my stereo, so that works without any problem, clear sound
i have a nokia microfoon and a mono sound amplifier as a line in to GND and pin 1
Thats brilliant cheers mate,
I am really wanting to try putting an external mic on as the phone is mounted down low and quite a way from the drivers head so i don't think the internal mic would pick up clearly..
What size amplifier do you have for your mic ?
I'm thinking maybe getting a handsfree mic and mounting it up by the drivers head, would something like this be suitable to use with that? : http://www.maplin.co.uk/products/module.asp?CartID=031221163652177&moduleno=2904
Thanks for all the help
i have something very similar like that
for my xda2 that is
maybe if you havent started the wirering and soldering. you could do like i did
get a LPT printer connector, it has more then sufficient connectors for each wire, and they have numbers!
ideal. for future plans.
then i just get a second connector and solder that to every componnent
Great!
If it used a tie-clip style microphone would I still need to use an amplifier with it, as I imagine the pickup is reasonably good on them..
Is 2.5W enough ?
Many Thanks :wink:
i dont know with xda1, if i connect a portable mp3 player to my xda2, i must set it to at least 2/4 of volume.
@akira :
I'm wondering where to connect Pin 19 to ground...
Can i just lead one wire out of the connector and ground it to the car, to the ground of the audio (pin 2) or should i connect it to another ground on the connector... ?
Btw, i disconnected the org. ground from the connector from pin 2 (less noise)... So i have onder Ground-audio out on pin 2...
jpiek: Have you made your own kit ?
I would be interested on how you done yours, how you rigged your microphone up etc..
Cheers
Neil
Not yet, i used to have juts audio-out from the GPS cable on my XDA I.
For the XDA/MDA II i need to ground Pin 19. I still haven't done that since i don't have a external MIC.
Now i wish to be able to ground pin 19 with a switch. If "on" it will shorten the connection and use audio-out (for TomTom). I hope to be able to use the BT headset for phone.
If i don't use audio-out, i can disconnect Pin 19 and use the inernal mic for voicedail etc....
Are there any news on that topic? How can I generate a mute signal?
thanks
Mütze
Hi,
I have a SPV E100 what should be simular to the XDA's. I want to to nearly the same. My setup should work with a Safe2talk Handsfree Kit where I want to connect the Speakers/Audio to the Navigation/Phone in of my Blaupunkt radio. I also want to use a serial GPS receiver. I read different articels in this forum but could not find a answer to my question.
How could I realize a mute funktion?
Cheers
PT-1
hello, I did this stuff here Alfa Romeo & Galaxy Tab integrating seamless the tab and my dashboard.
The overall result is very good, except for the audio volume, and being not an audio expert I fear that this is an impedence problem.
To make it very short, I just connected the headphone plug with the inputs of a 50W ("rms", real 50 watts they say, not fake 50w as standard OEM car audio), a kenwood KTP-500 thing. The problem is that the max volume is VERY VERY low in comparison to whatever oem standard ****ty car audio device, and that is quite impossible to me, and also for audio tuning shop owners I enquired for some advice.
So I think I need to convert, somehow, the signal to be good for the amplifier.
The amplifier has got switch between "low gain and high gain" but it does not change that much.
So I've got 2 plans to get an at least "normal" audio volume, amplifying the signal with some kind of "line amplifier", or find a guy (perhaps here? ) who can explain me the setup error, so that I can fix it. Shouln't be that difficult, but I'm ignorant in this stuff, and surprisingly, neither do know the people that works at kenwood/alpine/whateverBlingBling-audio shops in my city.
I also tried to debug my installation connecting a PSP, some other phones, a small television, an old cd player... all with the same low-volume result. So it's not a GalaxyTab (p1000, the good 'ol one, since it's exactly 2din fit) issue, but more general, having knowledge in audio signals may help...
So what is the point with connecting directly an earphone jack to the inputs of an amplifier? It's so amazing after 1 year having the tab as audio unit, it's a shame to have this volume issue è__é thanks for any clue
p.s. the audio quality is excellent, anyway, no buzz, humming or distortion. It's only... too low
I have the same problem, the volume is very very low, especially in a telephone conversation using speakers. However the sound quality is excellent. The problem is that you can not have a conversation without a headset ,when youare in a opne place.
Hey, I was just wondering if the audio jack on the DROID Turbo has the ability to receive audio as well as send. The reason is that my new headphones are Bluetooth only, and I was thinking maybe use an aux cord pc>phone, then transmit to headphones via phone's Bluetooth.
I mean the jack is a four pole TRRS connector which can accept microphone inputs so technically yes, however it would not be simple setup. you would need a custom cable to even get the signal going to the appropriate input and then you would have to insure that the input level is correct. All of that might be difficult depending on your skills with a soldering iron and ability to adjust the sound level but should be doable. The hard part would be to take the microphone input and send it out over bluetooth audio,again sounds doable to me but I don't really know to much about how to accomplish this part. Definitely a cool idea. Ultimately it might be easier to get a cheap bluetooth audio adapter for your computer