FM/DAB digital radio - THAT WORKS!!

I finally got around to rewriting the radio module in my FE. I added a real time signal strength bar, kbps display and a scrollable/selectable DAB station list that is not only controlled by touch screen but also a Rotary encoder in the centre console. I have 42 stations on air at the moment.

Anyway, decided to have a look at the DAB-FM module and check the PCB’s. I had noticed a strange noise, mainly on the bench with the DAB-module hooked up to the Tower PC – especially with the module muted or off but still USB powered.

Turns out the top and bottom ground planes of the USB-PSU PCB are not connected. The bottom ground plane floats off the USB socket case-ground. There are a dozen or so through holes in the PCB between the top and bottom planes however they are not connected. It appears the bottom plane is capacitive coupling/radiating noise from the connected unearthed USB shield to parts of the audio/RF module.

Because of the heavy quality coating on the PCB, even bolts going through the PCB don’t connect the grounds and I have 4 more for mounting the Module to the main chassis on standoffs. I connected both sides and the noise is greatly reduced on workshop tower PC.

This DAB module is mounted next to the PC case in the car. It shares not only a common chassis but a ground strap from the Sound IO Input shield of the PC to the RF shield on the module and another strap from the shield to the main case that holds the PC case, DAB module and PSU components. Lead lengths are in inches, so I had virtually no noise at all unless the radio was muted and the volume was cranked to full on the AMP.

However I was pleased to note that a few weak DAB signals are now much higher in strength.

Might be worth checking the ground planes, it may make a difference, especially with longer leads.

BTW – Mine was the last model released, it’s about 8 months old.

photos

Photo? There is not much to see in a picture of the PCB.

Howdy all, been away from this for a while, but a question has come up for me.

With TBM's plugin, where is the function to scan for station on DAB+ ? There is a new station launched since I tuned it last (on the old plugin I think) which I am keen to get. I've had a poke around but can't seem to find it.

Cheers

EDIT: Also, does the plugin support CF4?

Quote:

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Originally Posted by soyfish

... function to scan for station on DAB+ ? ...

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I scanned using the standalone DAB tool. The stations are then available in CF.

Re. CF4 I don't know. But I am interested like you since the DAB plugin is my No. 1 app.

what's the difference with plug ins?

I quickly installed CF4 the other day and the plug-in seems to work ... sort of. The radio plays when you select it from the home screen and it turns off when you go back to an MP3, but nothing seems to display on the main pane, like the station name or frequency etc.

I realized today that I didn't do the complete uninstall procedure for CF4 and it twigged my memory that the DAB Radio plugin was already in CF4 when I first started it up. So I have to un-install and re-install CF properly to work out some other things and hopefully doing that then adding the plug-in should sort it out. Will let you know.

The plug in dose work in 4.0, I've been using it alot. Only thing thats getting on my nerve is the hanging when sent to sleep/hibernation, same thing happens with the stand alone program.

Dose anybody have an idea how to fix this?

Thanks Redgy

It seems to be the luck of the draw with OS installation and Hardware (MB etc) allowing some to Hibernate/Sleep and others to fail. My new MB-OS install will not suspend with the DAB-FM module Port open. All I can think of is the Driver does not like data been fed to it from the radio as its suspending. Nothing worked including removing and reloading the interface driver. Hardware wise the module is located 4 inches from the MB USB port.

I wrote my own DAB-FM Interface and when I installed the new MB and OS I re-coded the FE to close the DAB-FM module and USB (com) Port on Sleep and Hibernate. The FE is coded to restart the DAB-FM module if had been running at suspend so it’s seamless to the user (me) and suspend/resume is now perfect.

Just coded compatibility for this in FreeICE now. Will be in Alpha 8 release. It's being tested at the mo.

Steve