FM/DAB digital radio - THAT WORKS!!

**Wolvers** · 08-25-2010, 01:30 PM

It sounds like you have the same issue as me then.

What I have now is a 470pf capacitor, in series, in the ground of the coax cable going to the radio unit. The only thing I may need to check is whether this is of the correct spec as you are using FM, and the frequencies are different to DAB. What i would suggest is that you try a 1nf capacitor first and see how you get on. You could go lower if there is still noise but that might affect the signal quality, maybe.

It's also possible that grounding the Venice7 module directly to chassis could help but I wasn't prepared to solder anything onto it and void any warranty it might have.

**mitchjs** · 08-25-2010, 03:15 PM

yawn...

STOP PLAYING WITH THE ANTENNA!!!!!

plug in a earphone, like from a ipod, directly into the board.. an with the Antenna connected, repeat your listening tests...

**nrgizerbunny** · 08-25-2010, 04:33 PM

i've hit a bit of a stumbling block with the sound over usb. I can't get the power down below 500mA, thus it will require 2 usb ports or external power, what's everyone's preference?

I'm thinking 2 USB ports might be the way forward.

**Roadwarrior** · 08-25-2010, 04:51 PM

Originally Posted by mitchjs

STOP PLAYING WITH THE ANTENNA!!!!!

But I like playing with my antenna, it is one of few things that I always like to play with

But back to serious business .

Originally Posted by mitchjs

plug in a earphone, like from a ipod, directly into the board.. an with the Antenna connected, repeat your listening tests...

You were right. I just tried that and I did not hear any whine but maybe the volume of the radio is so low that I cant hear it.

Maybe it was not such a bad idea that I ordered one of those

these days I just going

trying to get rid of sound problems that i have.

**jdmagoo1** · 08-25-2010, 05:05 PM

Originally Posted by nrgizerbunny

i've hit a bit of a stumbling block with the sound over usb. I can't get the power down below 500mA, thus it will require 2 usb ports or external power, what's everyone's preference?

I'm thinking 2 USB ports might be the way forward.

Sounds good to me, however if I have one USB port that outputs at 1000mA will I still require 2?

**Roadwarrior** · 08-25-2010, 05:17 PM

Originally Posted by nrgizerbunny

i've hit a bit of a stumbling block with the sound over usb. I can't get the power down below 500mA, thus it will require 2 usb ports or external power, what's everyone's preference?

I'm thinking 2 USB ports might be the way forward.

Something similar to this?

2 plugs that go into pc/usb hub and one that goes into the radio module.

Cant see anything wrong with that. Maybe it is possible to have the module with two options:
1. Audio over 3.5jack and then the user only have to use one USB plug
2. Audio over USB and then user would have to use two USB plugs, one for data/power and second one just for more power

Or maybe that would be to complicated

**jdmagoo1** · 08-25-2010, 05:28 PM

Craig I have a few more bugs,

- unable to clear lists via centrafuse plugin (can be done via stand alone)
- unable to turn auto on off in settings in centrafuse
- when I open up the plug in the radio turns on and off repeatly the only way to stop it is to hit the on/off button a few times. This also occurs in the stand alone version. If I open up the media player after having the radio plugin open, the media player will start to pause then play and pause again. The volume increasingly gets louder as well.
- the wav volume goes to maximum when opening the plug in
- CPU spikes straight to 100% when running the plug in
- I've had to uninstall the plug in because when centrafuse loads it becomes very very slow. This took a lot of testing to find the cause and it turns out to be the ultimate radio plugin. When I say very slow I mean hit the volume once and wait 3 mins before it reacts ( yes I did time it). I think this has something to do with the above bug where it turns on and off but am only guessing.

Thanks

James

**jdmagoo1** · 08-25-2010, 05:54 PM

Originally Posted by craigbrass;

Do you mean so you could name it like DAB Radio on the plugins ?

What I'm after is the ability to change the display name to whatever you want. At the moment the display name is 'ultimate dab', now the display name is what's written on the button when it's added within centrafuse, and I just want to rename it radio, however others may want DAB radio etc

**veletron** · 08-26-2010, 07:55 AM

Originally Posted by nrgizerbunny

i've hit a bit of a stumbling block with the sound over usb. I can't get the power down below 500mA, thus it will require 2 usb ports or external power, what's everyone's preference?

I'm thinking 2 USB ports might be the way forward.

Hi

I would prefer the option of both. I would suggest a linear regulator for the externally powered option so it can come right off 12V, but with the engine running you'd have a good 8-9V dropped across this which at 500mA might mean almost 5W of heat to get shot of somewhere. A SMPSU would be a better option (I get my SMPSU's out of fag lighter socket USB chargers!!). Obviously if it is just a 5V input then folk might wire it up across 12V and screw things up. Its pretty obvious where the USB plugs go!

I work with USB (hardware and device drivers) for a living. Very very few things (usb host & client) conform 100% to the USB spec. In fact most USB ports will let a device have far more than the device declares that it needs via the descriptor during enumeration. The whole thing has gotten lapse (almost by nessesity) due to the end user just wanting non-confrorming stuff bought for a quid off ebay to work anyway! I've seen some fairly ammusing non-powered hub designs with a large cap plonked across the rails!

The point of the above, is that you'll have ports that claim to be USB-2 compliant that will deliver less than 500mA and others that will deliver significantly more. In the case of a powered hub with little else connected, you'll generally not have issues pulling an amp or more from a single port.

I guess the end-solution depends on how you are implementing this:

- Bespoke, multi-function device, with own descriptor that can declare bus-powered or self powered at enumeration)

or

- An off the shelf 2 port USB hub with the DAB module on one port and a USB thumb soundcard on the other?

If its just an off-the-shelf 2 port hub that has the option of being self-powered then it should be easy to offer both options? Maybe having 2 USB sockets on the board is the way forward (second one only having power-lines connected). Users who can't get it to work with one USB cable can then connect a second cable, while those that know what they are doing re 5V external power could chop the USB plug off that second cable and wire it up via an aux 5V PSU (or gut a fag socket USB charger and use the innards!).

Nigel