N900 FM Radio Calling
 

I was wondering if it would be technically possible to on the N900 use the FM radio transmitter to make/receive calls. I want to do this because my car has a radio, but no bluetooth unit and want to try to utilize the transmitter for this purpose

Re: N900 FM Radio Calling
 

So why don't you try this out for yourself?

1. Hook your N900 into your car audio.
2. Try to make a call from the other handset.

It's simple as that, & tell us how was it :)

Re: N900 FM Radio Calling
 

But... But... But... It's easier to type the question than to go outside and try it.

:D

I have to agree with stan. Go find out by trying.

Re: N900 FM Radio Calling
 

hi guys he specs telling us that it isnt possible at the moment to share calls over the fm transmitter. But that one Guy asked about the technical possibility maybe for a future upgrade / Brainstorm?

So there is no reason to be so rude in my opinion.

best regards crown

Re: N900 FM Radio Calling
 

A walkie talkie app would be cool. not very useful though. I'm not sure about the distance the N900 is able to send FM, but it is probably not very long.

Re: N900 FM Radio Calling
 

I don't recall asking about that possibility.

Re: N900 FM Radio Calling
 

agreed. people want new users to adopt the n900 & maemo but when they can't see how to do something, and then subsequently ask, they are met with a 'go find out for yourself' response.

i will hopefully be a n900 user within a couple of weeks, and hope others are more helpful if I have a few simple questions.

giving a bad name to the maemo community.

Re: N900 FM Radio Calling
 

Yes, there's some people here that thinks that not knowing the answer is a good reason to blame who questioned it. I saw some of them too.

Anyway, im a noob so don't take me too seriously, these are my two cents:
i personally dont think its impossible to transmit calls through fm transmitter. its just that someone has to write an app for it, cause at the moment is not made for that. consider also that a similar app should automatically increase mic volume in order to make it possible for you to speak at some distance from the phone and in a noisy environment as a tripping car is. anyway i think a big limit to this to be developed could be the poor quality of the fm transmitter itself (as of now).

sorry for my bad english and the casual bullshits i could have said.

Re: N900 FM Radio Calling
 

I think that question is very relevant. I tried it myself a month ago and it can't but I think it is possible with a application by the way fm transmitter is very good with FM boost application I can get about 150 feet from my car and still broadcast

Re: N900 FM Radio Calling
 

hmmm .. just a concern for FM transmitting .. couldnt anyone just listen into your conversation .. (even if just accidentally) ... its not encrypted like BlueTooth pairings ..

Re: N900 FM Radio Calling
 

jd you lucky guy! im not able to transmit from more than a few inches far. for the same reason im not concerned at all about people listening to my conversation.

fm-boost does nothing to me. did you extra boosted it in some other way? or maybe you live in a desert... :)

Re: N900 FM Radio Calling
 

No I don't live in a desert. I just follow the fm boost thread. There is also a youtube how to use it.

find an empty channel. Once you transmit and play the song start the fm boost. It's funny I can go out of my car and walk for a good 150feet and still broadcast last Saturday night we were packing from one car to the other our luggage and we were listening musing loud my phone was in my pocket and was playing out loud in one of the car my friend was really impress!!!

Re: N900 FM Radio Calling
 

ok ill try these eve. i really hope it works!

Re: N900 FM Radio Calling
 

I'm not sure i understand the question. Are you asking if there's a way to use the FM transmitter to output a call through the car stereo system? Cars that actually support Bluetooth handsfree mode have microphones, buttons and other circuitry. Wouldn't the best you could do using the FM radio be the same as putting the N900 on speakerphone?

Re: N900 FM Radio Calling
 

I'd worry about this too. I've been able to pick up my transmission from quite a good distance from the radio (using boost), so I've no doubt it would be possible for someone driving next to you to tune in and listen.

Granted their radio would have to have sufficient reception, and granted they would have to find your station, but neither of those is out of the realm of possibility. I know I'd probably stop to listen just out of curiosity if I suddenly tuned in someone's phone call..

Re: N900 FM Radio Calling
 

Seriously???? You'd rather spoonfeed every person who is either too damned lazy or too damned stupid to actually TRY doing something for themselves before posting such a question as the OP? You go with your bad self and have a good time spoonfeeding lazy people, then.

Simple questions are not the same as dumb questions. And yes, there are such things as dumb questions. I don't care what Ms. Penny, the special ed teacher told you about there being no such thing as stupid/dumb questions.

I'm using "you" in general terms.

No, what gives a bad name to the Maemo community, are people who are either too stupid or too lazy to go and try something out for themselves before asking to be spoonfed. Unfortunately, there isn't an app for that.

The maemo community is about collaboration, not spoonfeeding. If you can't take a little criticism, you really should get off the net before the mean people make you cry.






And there are people here that would rather be spoonfed... Any IDIOT would have first tried to see if he could make an "FM call" before asking. Not to mention that any t00l would know that such functionality from the "factory" is idiotic, at best.

Was that so hard?

Re: N900 FM Radio Calling
 

When i read the OP I gathered that the user had looked on the phone, but had not seen anything, and was asking about the limitations of the device. That is the way I read it, as several others have. It is a valid question.

If it really makes you feel bigger, please continue to refer to people with special needs for 'comic effect' or whatever you see it as.

Re: N900 FM Radio Calling
 

No, I try that before, but it does not work using FM transmitter to transmit your call.

Since my car has an AUX jack, i am using that previously when the bluetooth was having problem.

But now with PR 1.1 , the bluetooth have been fixed, so I am back to my bluetooth car kit.

Re: N900 FM Radio Calling
 

@ that one guy

I answered because the topic interested me. Spoonfeeding, not spoonfeeding, i simply dont care. I was simply talkin about an argument that interested me. If you think that the question was so "IDIOT" why did you bother answering? ignoring stupid questions is the way to go for me.

anyway its not so idiotic for me as i have an old car whith an old radio in it, without aux and of course without bluetooth.
ok, the privacy could be a problem, the range too, but that makes it an idiotic topic? sorry i didnt came with the same conclusion as soon as you and wasted my time discussing it politely. im not so smart. please, stop losing your time with threads like this. your overwhelming intelligence embarass us and make us feel so miserasble...

Re: N900 FM Radio Calling
 

Clearly the question was about technical possibilities.

Should be possible.
1. Mic is good enough, from 1.5m distance sounds still quite clear
2. You could/should use a car stand. So that you can access the buttons and to fix the phone mic direction
3. The only technical (software) issue would be to direct the sound from calls to FM transmitter, the interesting part, but sadly very new to linux so ...

Yet, as already told. Why not use the speaker function? ;)

Re: N900 FM Radio Calling
 

heh, sorry for the delayed response (out all day etc) i had tried to connect through the transmitter prior to asking the question. i know that you can use the speakerphone but lets face it, another use for the fm transmitter and using the radio to call in any car would be quite cool apart from the obvious security risks. was just trying to see how viable it would be :P

Re: N900 FM Radio Calling
 

@ That One Guy - the more effort you put into trying to make other people look stupid by jumping to (incorrect) conclusions and then attempting to berate or belittle only serves to highlight your own idiocy. You're what's wrong with the internet. Shut up you flid.

Re: N900 FM Radio Calling
 

I am sorry for brining up an old thread but I just wanted to say that a few days ago I was listening to internet radio using my car stereo via the FM transmitter, when I suddenly received a call, I answered it, the N900 hang for a second and I could hear the call via the car radio (instead of the standard beeping sound).
(I could switch to speakphone and the phone speakers would work, and when I turned the speaker off I could continue talking via the car stereo).
anyway, after that call I tried to initiate another call but this time it didnt work, the call would come from the phone.
too bad this "bug" happend just one time and I dont know how to make it happen again.
But this proves that its technically possible.

If anyone could tell me how such a program could be written (what libraries etc.) I would be glad to try it.

Re: N900 FM Radio Calling
 

Did the other person hear you when you were talking?(conversation coming through car speakers) Or you had to put mic near you to speak back..?

Re: N900 FM Radio Calling
 

Well, I held the phone next to my ear when I started to talk but then I held it a bit farther, and the other side heared me with no problem (at least I think so, he didnt say "What?" or asked me to talk louder)

Re: N900 FM Radio Calling
 

Anyone working on this or is it even possible? My workplace is pretty loud so recieving calls through my fm-earmuffs would be great! Unfortnuatly I'm totally clueless on the programming front. :(

Re: N900 FM Radio Calling
 

Well, by default the device disables the FM Transmitter when you get a call - however, there's an app called FMTX Faker (though it's in Extras-Devel, not Extras, so use at your own risk) - it works by tricking the transmitter into thinking it's allowed to transmit, when normally some other program (like the phone) is telling it not to - so at the very least that covers the ability to receive a call and transmit it to your car at the same time, which is what the op was referring to, I believe...

To the last poster - if your FM earmuffs receive FM directly (and you're not talking about using headphones as the N900's FM antenna) then the above should cover it. You can get the FMTX Faker, and then have it set (I think it can be automatic) so that it tells the transmitter it is supposed to be enabled regardless of what else happens, when you get a call you can answer, enable the transmitter, and you're set.

There's another app, in Extras, which is called the "Simple FMTX desktop widget" - but I don't know if it can force the transmitter to be enabled in-call. What I would do is if you're not comfortable getting stuff from Extras-Devel, ask/read around, or download the Simple FMTX desktop widget first, then have someone call you and see if you can use the widget to enable the transmitter mid-call consistently. If you can, that's all you need. If not, but you really need the ability to have the N900 transmit the call by FM, then I suppose you could enable Extras-Devel, download the FMTX Faker, install that, and then disable Extras-Devel again (and it's probably safer to ignore any software updates while having extras-devel enabled because I THINK newer, less stable versions of programs are usually in the Extras-Testing/Devel repositories for at least a little while before they are good enough for end-user consumption).

- EDIT -

As for enabling full-on FM-Calling, which I can only imagine as both phones transmitting and receiving at the same frequencies (or Phone A transmits on the frequency phone B is picking up and vice versa, though that would be a pain to coordinate), without at all using their normal wireless networks, I suspect that something like that is possible, though you'd probably have it practically limited to walkie-talkie-like behavior. It could be possible to actually 'dial' another phone through FM radio, but I think that's ridiculously beyond the scope of practicality, since both phones would have to be actively transmitting some sort of identifier on the FM, which would honestly just cause FM jamming for everyone around you, and you'd probably have to come up with your own protocol just to make it work (maybe not - when it comes to the actual technicalities of programming I am a newb) - however, I suspect walkie-talkie functionality should be possible, if you could get the N900 transmitting and receiving on the same channel, without using the input from the FM receiver as output for the transmitter, since that would cause feedback. I haven't actually tested receiving on one channel and transmitting on another to see if that's how it would work, but I suspect that's exactly what would happen. ...if the transmitter of N900 A doesn't just completely over-power the signal of the other N900 B that N900 A's receiver is trying to pick up. That's more of a needs-to-be-tested hardware question, though.

Re: N900 FM Radio Calling
 

FMTX Faker tricks the FMTx daemon into thinking it can be enabled initially; devices with it disabled will show a "FM transmitter disabled" message regardless of the situation you're trying to utilize it in.

The Simple FMTX Widget just turns on transmission through the D-Bus interface provided by the FMTx daemon - fmtxd can and does veto the turning on of the transmitter in certain cases.

Re: N900 FM Radio Calling
 

Ah. My apologies for the mis-information then. So, in that case, if you don't mind explaining, I have to ask - what practical application does the FMTX Faker have?

Re: N900 FM Radio Calling
 

I believe people in Serbia, Greece and Hong Kong have use for it as the regulations of those countries required Nokia to disable the transmitter in software in devices sold in those countries :)

(Although it's said that 5800s sold in those countries have their transmitters working regardless...)

Re: N900 FM Radio Calling
 

it is impossible. they use different frequency and wave.
That's it.
And must build special hardware to do that. Mobile device is No NO No

Re: N900 FM Radio Calling
 

@ qwerty12: Oooh... Ok. Thanks.

Could the same principle be applied to permanently forcing the daemon to allow enabling of the transmitter? It seems like it would just from what I know, but what I know is not a lot, so perhaps that's just not doable without seriously screwing with the N900.

- Edit -

Heh, I totally had no idea you wrote FMTX Faker, lol. After posting the original part of this post I went off to go look around since it seemed like the appropriate time to go research the matter instead of getting spoon-fed. And then half way through the "How to enable FM transmitter? (Solution in thread)" thread you just come in with a fix. I mean, I've seen your name enough around here while lurking since I got my N900 a month or so ago (and for close to a year, with increasing frequency, as my opinion solidified that I wanted one), that I knew you must be knowledgeable and good, but damn. Of course, maybe that's far less impressive than it seems to me... (to be fair I'm impressed by frals for fMMS and Titan + everyone-else-that-works-on-kernels too...) I have little frame of reference other than how much more or less daunting anything seems to me.

That said though, every wiki page that turned up for "FMTX" (I got only three - I believe I was in the "fremantle" category; perhaps there are others that would turn up if I searched everything else?) had nothing that answered my above question. Currently finishing reading the aforementioned enabling FM transmitter thread, so maybe that will cover it. But if you know an answer to my original question in this post that would be appreciated.

Re: N900 FM Radio Calling
 

What?! You doubted Qwerty the Pimp?! I must get my revenge by coming up with a hack to this problem!

Prerequisite:
fmtxd patched: fmtxd, using http://maemo.org/api_refs/5.0/5.0-fi...5a46afdad43a94, checks to see if you're in a call. So open up /usr/sbin/fmtxd in a hex-editor (I used vi on the tablet itself) and replace "sig_call_state_ind" with "sig_call_sttte_ind". Make sure that the transmitter isn't on whilst doing this and that fmtxd is not running.

1. Install http://talk.maemo.org/showthread.php?t=43395 (the fm_boost variant may be better, depends) (not required but you'll find it easier)
2. Unzip the attached somewhere.
3. Make a call, hit Speaker and turn on the FM Transmitter (you'll see why 1. makes this easier...)
4. As root, run "alsactl -f /speaker_fmtx_on restore" with "/speaker_fmtx_on" being wherever you placed that file.

Oh, the interference is a *****. I may write a daemon to make this easier.

Re: N900 FM Radio Calling
 

Sorry for delay, I was writing up a detailed review for the current extras-devel release of the universal portrait mode virtual keyboard.

Anyway, on the one hand, the complexity and lack of a .exe in a friendly Windows formal scares me. On the other hand, fear is for the weak, and the N900 does not accept the weak as it's users (but seriously I got this device planning to use it as leverage to make myself learn stuff like this, so I'll dive right in).

Actually, I just read it again and though about and and it seems relatively simple. Override the proprietary FM Transmitter applet with yours, get a random program/script thing, which somehow is tied to the speaker being on, and then call/get-called -> speaker -> fancy script.

Couple of questions: firmware updates - would they override the FM transmitter applet, requiring overriding it again?

Does it matter what I change sig_call_state_ind to? It seems like I'm just changing state to sttte in that example just to force FMTXD not to recognize that particular line (or rather not have anything to reference when it gets that particular 'command'/whatever), and that the sttte is just a change meant to make it easy to remember, find, and and fix that line of the fmtxd later. Correct?

Anyway, I will try this soon, most likely. By the way, what do alsactl and -f mean in the alsactl -f (filepath to that attached unarchived file) command/script? Because I would remember it better on-the-fly if I could attach a meaning to that command.

At any rate, thanks. I hope it helps the poster before me, though.

Re: N900 FM Radio Calling
 

Oh, I'm working on a DEB but with the amount of hacks that are gonna be in it, I can't promise it'll be good... :eek:

Yes, but it's unlikely that it will get an update - it was not updated in PR 1.2, e.g.

Correct. Make sure you're changing it to something of the same length, however!

It loads the sound settings from that file. It's pretty much the key to it all: By enabling the speaker and the FMTX control, we can make the sound go to the FM transmitter.

Re: N900 FM Radio Calling
 

Great that you are working on this, would be very helpful at work. One question though, will this work (if you build a "app" for it) when I listen to fm-transmitter (beacause I always do at work), then if there is a call I just answer or do I have to push the "widget button" and then answer the call?

I have yet not used xterminal or extras-devel (well sixaxis I tried) for that matter, and I think xterminal is way out of my league. But if this will show up in extras-devel I have reason to at least try that out.

One more question turned up. Will this work with 1.1?
I'm far to happy with my n900 to try 1.2 out. ;)

Thanks for all answers guys and sorry for my poor english!
I will keep my eyes open for this! :)

/applehorn

Re: N900 FM Radio Calling
 

Well, I'd do the non deb way because it seems more fun (IE challenging), but I'm guessing if I want to make the updates that the deb would get if it's officially run through here I'd have to then download and install the deb?

Yay to me being correct. I would ask why it has to be the same length but perhaps seeing it in the file itself would make that make more sense.

Anyway, thanks for answering all my questions.

Applehorn: I am pretty sure that this should work fine in PR1.1. Honestly, though, I personally recommend updating to PR1.2. Up to you of course, and it depends on what your needs are, but so far I'm a fan of PR1.2, with my only real annoyances being minor (app manager and tiny disagreement with a specific browser detail). For me PR1.2 has been an essentially positive update. That said as far as I know this method should work the same with PR1.1.

Re: N900 FM Radio Calling
 

I was looking for exactly this, and based on the instructions above I created a small program to make this work while driving the car.

What is does:

1. Start the program (source attached)
2. If call state changes to active the fm transmitter is started
3. Enable your speaker manualy
4. Press the camera button, the sound is routed to fm-transmitter.
5. If the call is ended the sound is set to its original state: ("alsactl -f /var/lib/alsa/asound.state restore")

ATTENTION: The program is totally modified for my own phone and configuration, e.g. the paths in the file are hardcoded.

What should be nice:
- Store the original sound settings before routing the sound, this saved state file can be restored after ending the call.
- Nice desktop widget, or phone profile (silent, general, fm-carkit)
- dbus signal to check for enabled speaker (then the camera button signal is not needed anymore)

The code isn't great at all, but it works for me and maybe someone can use it or extend it.

Thanks to user Qwerty12, I found also some dbus integration of him in another topic.

Re: N900 FM Radio Calling
 

This should be in the repositories! :)

Love this concept. Would be nice if there was a gui so we can change some settings like you said Roeland

Re: N900 FM Radio Calling
 

Some features requested:

Phone number can be transmitted by RDS to the radio BEFORE accepting the call.

So you can choose if you want to respond.

(Other features of the "RDS Notify" Widget could also be implemented.
In addititon there could be a notification for emails or social services.)