FM radio transmitter idea
 

i've came up with an idea for my N900. before my N900 i've had de N78, both phones have a FM transmitter that i often use.

but the FM frequencies are a bit crowded. sometimes it's hard to find a good free frequency. but when you're driving somewhere you may come across other transmitters, then you need to find a new frequency.

but i've came up with an idea;
what if there was an application that scanned the frequencies using the FM radio app and logged where there are radio stations and where there is only static.
it then gives a empty frequency to the FM transmitter app.

i really hope something like this exists or that someone wants to pick up on this project. because i hate changing the frequency every time.

Re: FM radio transmitter idea
 

Good idea, however you always transmit to a radio, so usually you can easily find an empty frequency with this radio, and then set the transmiter to it.

Re: FM radio transmitter idea
 

yes, but in my case, on my radio are 2 push buttons and not a small knob so i have to cycle through the whole band. and sometimes when i thought i had found a free channel and fired my N900 up it still wasn't a good channel, much interference from another transmitter.

Re: FM radio transmitter idea
 

Habrat, changing channel while driving???? It sounds crazy, I don't want to commit suicide!
And no, it's no easy to find all-time-free channels if you drive every day two houndred kilometers crossing valleys, mountains and cities.
The idea of Oddish is great!

Re: FM radio transmitter idea
 

In addition, my radio doesn't have manual tuning so it's hard to tell where the free frequencies are without paying quite a bit of attention. Certainly not while driving...

If the N900 could automatically pick the frequency which was furthest from any detected station, it'd be a huge help.

Re: FM radio transmitter idea
 

My FM transmitter is utterly useles! It never transmits nothing no matter how hard I try...pls can anyone direct me to a thread to sort out this problem? I done downloaded fm boost...no luck still!

Re: FM radio transmitter idea
 

As far as I remember, in order for the N900 to pick up radio transmission, it has to have the headphones connected - no?
So, in order for this idea to work, you'll have to first connect the headphones to the N900, allow it to scan frequencies and do his thing (find an "empty" frequency), and then disconnect the headphones and activate the FM transmitter... Do you ALWAYS drive your car with your headphones somewhere with you? because if you don't, you can't use this type of function...
In addition, as far as I know the N900 RECEIVER is significantly less capable than an ordinary car's receiver, so normally stations that will be picked easily by your car's radio will not be picked as much as easily (or even - not at all) with your N900.

Nevertheless - don't get me wrong, the idea is very nice but I'm not quite sure how practical it is...

Re: FM radio transmitter idea
 

Niggydip... FMtransmitter with fmboost (actived) works, it's not perfect, but, with free channels, works. Do you activate FMtrnasmitter before of after opening player and before of after connecting to usb-car-charger?
It ALWAYS must be enabled AFTER, try disabling-enabling again if something goes wrong.

Re: FM radio transmitter idea
 

Thanks mate...to activate fm boost, all I gotta do is tab d shortcut I created on d desktop right?(usually nothing happens afterwards though) Well I usually launch fm boost(supposedly) then try transmitting via d FM transmitter and regardless of d frequency I set my car steroe to I dont get any audio...even when I attempt to transmit after I open Media Player...

Re: FM radio transmitter idea
 

you may find the ideas in this post for expanding the transmittable wavelength useful: http://talk.maemo.org/showthread.php...212#post585212

you may find its not useful or possibly against the law in your area, but worth a look regardless.

Re: FM radio transmitter idea
 

That's true. However, according to the driver documentation, the transmitter chip is capable of measuring received noise level. Couldn't that be used to find an appropriate frequency? Additionally, the transmitter seems to support RDS, so maybe an alternative frequency table could be used to automatically switch the frequency on both the N900 and the radio receiver.

Re: FM radio transmitter idea
 

You should start fmboost AFTER starting fm transmitter. If you plug or unplug cables, start or stop fm transmitter, the boost is undone.

Re: FM radio transmitter idea
 

shadowjk, fmboost is now integrated in Simple fmtx desktop widget, you must only configure the widget to use it.

Re: FM radio transmitter idea
 

I thought I'd dig this one out because I'm about to take a motorway/freeway trip tomorrow and have to take the car which doesn't have an aux input on the radio, so that means using the N900 FM transmitter. Being a long trip, this will invariably mean changing frequencies on both the N900 and radio from time to time to keep the frequency clear. This wouldn't be so bad if I could convince the wife to drive, but it'll be me driving as usual, so I won't be able to keep fiddling with the frequencies without pulling over every dozen miles or so.

The original poster was onto a good thing with this and it was working out, but the thread kind of fizzled out when discussing using fmboost.

There is still a good case for developing a program to scan for clear frequencies. This could either be used to build a map of clear frequencies on specific frequently travelled routes (motorway networks perhaps), or as was suggested, perhaps to use RDS to enable the FM transmitter to renegotiate the 'station frequency' on the fly. I presume that the N900 is not capable of transmitting and receiving simultaneously, anyone know this?

Changes of designated frequency could be triggered by GPS location if a community created 'clear frequency map' was developed from the pooled N900 users frequency scans. The resultant frequency map might be used as the basis for the development of similar applications on other platforms, a bit like those dynamic speed camera databases.

It's all too complicated for me to even contemplate, but it would be dead neat if it could be made to work.

Re: FM radio transmitter idea
 

Here is something everyone can do to get trouble free transmission from your N900 to car radio.

Either unscrew the whip or push down the antenna (depending on the type of radio antenna fitted) or try the following...
what is needed is a simple switch to disconnect the antenna wire from your radio, the centre wire in the coax of your antenna lead going to the actual antenna on your car, what this will in fact do is stop the antenna from working and will give you a quiet radio that will pick up the local transmission from your N900 as it will be in the car without any interference from an outside broadcast.

Worth a try.

Re: FM radio transmitter idea
 

rather sound idea! cut the coax somewhere accessible (under steering wheel most likely) and install male / female adaptors to the cut ends, the ones for old tv aerials would work just fine, 99p at B&Q, and if you really want to make sure run an alternate connection to beside your cubby-hole or wherever you keep your n900 while driving.

personally i get a fantastic signal all the time on 1 frequency, keeping my n900 in the cubby-hole directly below my stereo.

Re: FM radio transmitter idea
 

Yep good idea that as all you need to do is null the signal from the antenna stop it from getting to the radio.
Incidently you can buy an antenna switch, switch out the external antenna is all thats needed.

Re: FM radio transmitter idea
 

The fm transmitter chip actually has the capability to scan for least noisy channels and transmit there.. I don't think the kernel driver supports it though. I don't know if it can send and scan at same time.