Thread: For Guino: USB Radio FM with RDS from Silabs

Hello all,

As some of you may know I have modified the SiLabs source to be ran from a DLL, and have given it a Radiator compatible interface.

I've tested this within RoadRunner and it works fine.

However, I wanted to remove Radiator from the loop, so I tried (somewhat successfully) to integrate it into RR natively. The motivation for doing this is for faster tuning, scanning, etc.

I have a few problems with the RR integration, mostly from a lack of experience using VC to import DLL functions, but the basic functionality does work and I'm using it in my truck.

I've attached the Source for my DLL and the modified radiator.bas file from the roadrunner source.

Since I only have one of these devices, and it's now working to my needs I can only minorly support the code since the device is firmly behind my dash.

Some things that need to be worked out in my VB code:

[1] Using the RDS functionality.
[2] Sometimes when starting the radio from hibernation the station select reads one station, while the radio is actually playing a different station.
[3] I was only able to get the forward/backward buttons to work from the radio skin.

Using the Radiator interface does not have problems 2 and 3.

I hope this minor contribution is useful to someone, as the contributions from the MP3Car.com forum have been very useful to me and I'd like to repay a part of that "debt".

Thanks

Originally Posted by RRMobile

Hi

After spent all the WE coding I ported "most" of the original C++ application to VB6.

I'm still working but I managed to port all the USB HID low level communication.

The biggest part that is missing now is the Audio Management only because I'm looking for some good VB6 example that is able to play external sources.

The only reference i found is the "Audio Input/Output level" example that can be found at: http://www.allapi.net/apilist/mixerOpen.shtml#
If anyone has a better VB6 example please post.

I attached the source code of what has been done so far.

Hi RRMobile,

I'd strongly urge you to avoid going down this route, to avoid frustrating yourself.

Playback of audio at process level is an extremely latency sensitive operation. From my understanding of VB, it's not the best language to use if speed is imperative, as it in this situation.

The best solution would be to do this work at kernel level, which would require use of the Direct Sound API, or if you wrote some custom drivers. I know this is doable from C++, but I'm not sure if VB has the ability to interface with that API.

I have used Direct Draw (btw, Direct Sound and Direct Draw are parts of Direct X) in the past, but never Direct Sound - and I am just too busy to learn something new right now (I'll probably get to that eventually).

Cheers

@Wickerswammie:
thanks for your contribution!

After a quick look to the source, it seems like there is no TA (traffic announcement) information processed in RDSData?

If i am right, can it be done? If i am wrong, where can i find it?

This is the most important feature for me - if there is some accident or some danger, they transmit it via the TA feature - i will just monitor this flag and switch to radio if it is set.
c ya

Originally Posted by ReflexNPG

@Wickerswammie:
thanks for your contribution!

After a quick look to the source, it seems like there is no TA (traffic announcement) information processed in RDSData?

If i am right, can it be done? If i am wrong, where can i find it?

This is the most important feature for me - if there is some accident or some danger, they transmit it via the TA feature - i will just monitor this flag and switch to radio if it is set.
c ya

You are correct about that. The firmware currently does not support the TA feature. I'm sure it would be possible to add it - but I'm not sure what would be required to do so. The firmware was included in the source SiLabs provided so if you can program firmware then you could theoretically get this little device to give you the TA.

Originally Posted by rando

How does the device perform for you on the road? Feel free to slap me if I missed your review.

I've not given a review yet, I've been trying to give it a few days in the truck to see how I feel about it.

I will give first impressions though.

It performs good when stationary (no pops/cracks in the audio at all). When I am moving I get infrequent pops in the audio that seem to be radio related (I don't hear them when listening to mp3s).

The external antenna was not as helpful as I had hoped, but it is better than not connecting it at all. I experiemented with the little wire, giving it random positions within my dash, all with no luck. If I taped it up the middle of my front windshield reception was perfect (did not try that moving), but I'm not going down that route. Using the bare wire in my dash without connecting it to the external antenna was wretched.

I soldered the wire to an adapter I found at Best Buy which connects to my stock antenna wire.

I never really liked radio much in the first place, so my expectations arn't exactly high. It works to my satisfaction now, but some radio listeners may be a little more discriminating than myself.

Since the device doesn't currently support TA, it holds little value to me besides the occassional NPR. (The other forms of RDS do work well, so perhaps there could be a firmware update to allow TA to function).