[Q] GFMAPI Project - FM Radio RSSI to dB? - General Questions and Answers

Hi everyone,
I'm working on a project that uses the GFMAPI library that allows a developer to make use of the FM radio capabilities of a phone. I have an HTC Touch Diamond phone running Windows Mobile 6, and everything is working fine. I can get a measure of RSSI (received signal strength indicator) for any given radio station.
According to the Wikipedia article for RSSI, there is no standard definition of how to convert an arbitrary RSSI value to decibels (dB). My question is, does anyone know of a way to do this? I tried looking for manufacturing specifications for my particular phone, but couldn't fine anything useful. Perhaps someone else has had this problem?
Thanks for any help you can offer.
-Mike

Related

FM Radio Question

Does it annoy anyone else that it is impossible (as far as I can see) to allocate a meaningful label to the presets on the FM radio application so that all you can do is store them by frequency number?
If I have 10 presets set up it seems so obvious to me that I would actually want to see them as things like "Radio 1", "Radio 4", "Capital", "Virgin", or whatever rather than <xy.z>MHz and have to remember what station is on what frequency/preset.
Are there any third-party FM apps that can talk to the HTC hardware? I know there are lots of apps out there to listen to streaming internet radio but since the tuner is hardware specific I suspect the app that drives the FM tuner is probably HTC-specific and written by HTC. I'd love to be proved wrong or for someone to tell me that I've just not seen the feature to allow me to assign a label or that there's a registry hack or something.
- Julian
I can't help here as I'm still waiting for the O2 version but, I thought this phone supports RDS. Is that not true? And if so, doesn't it automatically name the stations it finds?
Paul
pmeekin said:
I can't help here as I'm still waiting for the O2 version but, I thought this phone supports RDS. Is that not true? And if so, doesn't it automatically name the stations it finds?
Paul
Click to expand...
Click to collapse
It does support RDS, and it works in the UK, but unfortunately the RDS data is only displayed once you've tuned into the station and it doesn't save the info against the preset so there's no way of using the RDS data to decide which preset to select in the first place.
This isn't a huge deal, it just infuriates me because this is such an obvious feature and I just think it's a bad piece of software design.
- Julian

GNSS Internet Radio and Built in GPS

Hello,
I am new to the forum and also the owner of an HTC Fuze. I have been playing around recently with the GPS on the phone and got me thinking. I live in NY and we have a CORS network of gps base stations that are fed by the use of ntrip.
I was wondering if their was any way to use the gps signal on my phone and the connection to this CORS network to give me sub inch accuracy on my phone...then not sure what I would do with it then. But I do live on a farm and I would like to see some type of precision agricultural use.
I guess I need a way to have the GPS on the phone talk with the GNSS internet radio and then give me spot on guidance and such.
Please let me know your thoughts or if I need to explain better.
Thanks,
Clayton
bump
bump. Any ideas? Anyone
Great idea cwrisrey !
That will save the cost of a geodetic device, which is many times the cost of a Fuze. Further, it will lead the accuracy of the buildin GPS into millimum class.
Not dig into this further, would you go further to tell these:
Is that CORS data encrypted?
Is that accessible through public internet or VPN?
Is there copy right or intellectuall property right issue involved? (I don't think so, but better make it clear first)
Once again, great idea. Please do remember to update this thread once you got any progress. Thanks.
More info
Hello wg5566,
This site would probably answer alot of your questions clearer than I could:
http://www6.nysdot.gov/spiderweb/frmIndex.aspx
* Is that CORS data encrypted?
-I don't believe so, I think that it is just a form of compression, to distribute across the internet.
* Is that accessible through public internet or VPN?
Yes, the NYS CORS anyway. It accessible from the public internet (although they require you to register with them) But I believe there are other free streams. I also believe it was modeled after being able to be sent threw GPRS.
* Is there copy right or intellectuall property right issue involved? (I don't think so, but better make it clear first)
-I believe the ntrip is based on a GNU, I think the source code is available. http://igs.bkg.bund.de/index_ntrip_down.htm
Windows CE version:
http://www.ilmb.gov.bc.ca/crgb/gsr/downloads/installGNSS.CAB
Please, let me know your thoughts...
Thanks,
Clayton
My fast thoughts:
First make sure there is no satisfied freeware currently available for WM.
If so please ask a moderator to move this to the development & hackings section. And Add tyis sentence on the title: Call for developers for revolutionary GPS app!
I'm sure somebody here can develop this. You know the geodetic device was invented many years ago with very weak profiles comparing to current WM devices. The hardware on our phone should be capable to deal with these calculations, and the WM Pro platform should be capable to support such an app. Anyway it should not be a biggy for many masters here. But it is a biggy for gps users with high accuracy demand for any reason.
Edit: Did you try install that wince cab on your phone? I think some of WINCE apps can just run on WM. Please backup your data first.
Edit2: I tried to install it on my device, at first it did not show up in start menu, then I found the cab just put files and shortcut in the folder names in French. But there is no registry involved in the cab. Only three files. And then program UI itself is in English. Just run the executable from the folder will go right out of the box. So please try it. I did not try to connect & loggin yet, due to not registered account.
Edit3: Looks like the cab is only access the data from internet, convert the data format and export the data, but we still need a geodetic/gps software to process/use the data.
Disclaimer: I attatched these three files for the only purppose of exchanging software developement infomation. Anybody if download it please do not use it for any purppose other than this. Thanx.
Some thoughts on the subject
Hi All,
The idea of using NTRIP to make a Windows Mobile GPS device sub-meter accurate crossed my mind. After some research I found this thread.
Unfortunately, I haven't been able to find any software capable of doing this. My idea is that it should be possible to accomplish this goal, using a combination of existing tools (which would be really cool!).
As wg5566 notes, there is a (WM) tool called GNSS Internet Radio, which is capable of downloading NTRIP corrections. It turns out this software works, but does have some flaws. Someone wrote another open source tool which is better (?), but unfortunately it isn't built for Windows Mobile (see: http://lefebure.com/software/).
More searching revealed a (dead?) project on codeplex: SharpGPS. It's an unfinished demo. It does however seem to be designed to do exactly what we're suggesting in this thread.
My idea: Completing the WM version of SharpGPS with parts of GNSS Internet radio / lefebure NTRIP client should result in a tool that's capable of upgrading a WM devices' gps signal to sub-meter accuracy through RTK/DGPS corrections over NTRIP.
Any ideas / suggestions about this?
It's already been done for the commercial market
Land surveyors, construction companies, and farmers use RTK GPS and RTK GNSS correction services on a regular basis. Some are free and some are paid subscription. They can be either NTRIP protocol with casters or individual TCP or UDP connections. Examples of software available are Carlson SurvCE and MicroSurvey. Read Carlson's support site for how they deal with the data flow using such networks on SurvCE (Windows Mobile and CE).
I have worked in land surveying using such equipment, and it generally requires dual frequency receivers, RTK corrections, and high quality antennas to achieve 1-2cm 95% CI horizontal precision. The current GPS chips in cell phones are only single frequency and so the best you could expect under ideal conditions is 2'-3' precision using some form of differential correction like WAAS or beacon or DGPS via NTRIP. Under average conditions, the precision will likely be in the 10-20' range. The dual frequency receivers take care of the large errors caused by radio waves traveling through the ionosphere.
Due to the limitations of batteries, antennas, and space for more chips in cellphones, the future of location accuracy will likely include some combination of GPS/GLONASS and cellular radio signal frequency timing calculations from cell towers. True Position, with its U-TDOA technology, is one example of measuring the time differences of cell phone radio waves using cell towers with known coordinates. Rumors (from surveying journals) have it that there are current patents in place that can allow for sub foot precision using such methods when sufficient cell towers are present for multilateration.
Has anyone found success on this topic? WM or Android...
Would be very interested, since there is a free NTRIP feed available in Switzerland... anyone?
*bump* it up
Been there still trying. Problem is no carrier phase off internal gps.
Grimli said:
Hi All,
The idea of using NTRIP to make a Windows Mobile GPS device sub-meter accurate crossed my mind. After some research I found this thread.
As wg5566 notes, there is a (WM) tool called GNSS Internet Radio, which is capable of downloading NTRIP corrections. It turns out this software works, but does have some flaws. Someone wrote another open source tool which is better (?), but unfortunately it isn't built for Windows Mobile (see: /lefebure.com/software/).
Click to expand...
Click to collapse
Lance lefebure is a really cool guy I'm sure he wouldn't have any problem building a wm version but it is going to takea lot more than that to get rtk to a cell phone.
Very good ,thanks.
Ed hardy bikini said:
Very good ,thanks.
Click to expand...
Click to collapse
If you are confused just ask questions and I will do my best to answer them. I am in the ag industry and deal with RTK networks and different ways of connecting them and tons of different gps units on a daily basis.
Look at this:
http://stakemill.wordpress.com/2010/07/19/ashtech-mobile-mapper-100-supports-esri-arcpad-10-0/
and this:
http://www.ashtech.com/-2359.kjsp?RH=1272644205746&RF=1270806507068
Is that still a phone !?
wg5566 said:
Look at this:
Is that still a phone !?
Click to expand...
Click to collapse
Nope PDA with support for external GPS with a builtin reciever that even sees glonass satellites (russian constelation). That was made specifically to do RTK mapping. It does have a GSM radio for data to connect to the cors.
Phone positioning using CORS
To perform a CORS (Network Reference correction we need a GGA stream from the GPS in your device. This allows us to remove the anomalies and provde the correction stream. As phones use a sirf II chip or similar they do not have input capability to output the NMEA stream to achieve this.
This one works great! it will connect to an Rtk receiver and get the nmea string from it or will use the internal GPS to be able to register on the CORS network. It will then stream the corrections over Bluetooth to a receiver or even a repeater radio. It won't however correct the internal GPS. http://antrip.dyndns.biz/Home/DownloadTrial

Use HTC Touch Diamond 2 as a remote for a rc car

Hi everyone,
Okay, here is the idea. I have a HTC Touch Diamond 2 and I was thinking that it could be interesting to try to use it as a remote control to pilot a small car or plane (using the Bluetooth frequency).
I found several receivers in the 2.4 GHz frequency band, but I'm not sure whether it could work or not. Here are a few: link 1, link 2, link 3.
So the main questions are:
- Is it possible to program my HTC so that it sends information the receiver will 'understand'?
- Is there by any chance already an app that allows me to do just that (or something close to it that would need minor modifications)?
On top of this, I was also thinking of adding a camera on the car that would send back to my phone what it records. But this more than optional since it probably will make things much more complex... (I found transceivers such as this one and this one, but it looks like a lot of work to install and configure them).
Thank you for your answers and your help in advance!
Anyone to help me?
It won't work, sorry. Not with any store bought RC car. Your only chance is if you engineer the receiver yourself, including the circuitry that translates the radio signals into motor signals.
Thank you for your reply!
Ah, that's quite disappointing
But just to make sure, can you tell me exactly where the problem is? I mean is it a true hardware problem, in relation with the kind of signal that I can transmit with my phone (like a frequency incompatibility or something else)?
I was hoping it was possible to program my HTC to send the appropriate signal corresponding to what the receiver is expecting to get. Why couldn't it work?
Am I at least asking my question on the appropriate section of the forum, or is there another one that I should use rather than this one? Thx again.

android.telephony library missing informations

Hi, i'm currently making an application using the android.telephony library. But i need more information that the one provided by the api. I have two problem. First, the phonestatelisten seems to be not sensitive enough. I'm using onsignalstrentghchanged and the value gets updated not very often. In my opinion, the hardware is capable of being more sensitive wich means there must be a way of telling the listener reduce the threshold before stating the signal as changed and update. But i looked in ril and it seems the information isn't there.
And my second problem is related. It's that the neighbor list is getting populated only when the device is looking to change the antenna its linked to. I would like to constantly get all the neighbors scanned by the phone.
Does someone have any kind of information about that please?

Can Android device transmit radio frequency?

I have gone through many articles in the internet but couldn't find anything related to this. I wanted to know if android has the capabilities to transmit radio frequency so that it can be used for playing the songs in the smartphone directly to the nearby radio by making the smartphone as a radio station.
Yes, but you need some external RF hardware - check out GNU radio and the general subject area of Software Defined Radio.
Hmm I know some Android Phones may have it build in a Hardware for.
My "old" Nokia Phone have that native feature.

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