New (Car) Multimedia Cape

Hello everybody,

I have just received first sample boards of my CarStreamer cape for Beaglebone.
CarStreamer includes:

4x50W(RMS) Class-D Audio Amplifier (FDA450) connected to McASP0 and I2C
Stereo Audio Codec with 2x LineOut, 2x LineIn and 1x Mic In (TLV320AIC3104)
FM/DAB receiver circuit (with RDS support, …) connected to McASP1 and UART
5V 3A Step-Down Power Supply
Infrared Remote Control receiver

My plan is to use it as Car Radio replacement in my classic cars, so I can have high fidelity audio playback and latest media connectivity (via USB, SD-Card and Bluetooth) without destroying the look of my dashboard with one of these ugly aftermarket car radios.
But of course the cape can also be used to extend your BeagleBone to a powerful home hifi system.

The user interface is displayed on my Smartphone (I have started to develop an Android App for this based on Qt for Android which already works quite well) and I can benefit from, the phone’s Navigation and voice recognition feature.
Of course I can use CarStreamer as Hands-Free Telephony system with integrated Echo Cancellation and Noise Reduction feature.
The hardware was designed according to Automotive OEMs requirements, so should very reliable and ruggedized.

Carstreamer firmware is based on kernel 3.8 with an extension to the existing device tree.
The main SW is written using the Qt framework for the application part and the audio framework is using PulseAudio. I have written a Plugin that integrates a powerful Audio Equalizing scheme incl. standard filters such as Bass, Mid, Treble, Graphics EQs but also Speaker Frequency Gain correction, Dynamic Bass boost and Limiters.
It also integrates the EC/NR for Telephony and handles things like sample rate conversion and Bluetooth AADP audio.
Next step for the Application is to integrate a Media Parser and Playback Engine for SD and USB media (any recommendations for libs/frameworks from your side) ?

If anybody is interested in working on this project (the Android app or the Linux firmware) or on sample boards, please let me know.
If am planning to release schematics and gerber files as soon as I have verified all parts of the boards.

Currently more or less all peripherals of the Cape are working as expected (so yes, I can hear DAB radio stations through the speaker outputs of the Class-D amp :-)) but I had to integrate some tweaks and patches to the 3.8 kernel (e.g. enabling multi-serializer support on the McASP).

Please let me know if you have any suggestions / proposals for enhancements or if you wish to know more about it.
I am really planning to release the cape hardware and a aluminium extrusion housing as complete product in Q3/2014.


With the CAN network it could be possible to have information as vehicle speed and engine speed.

This could allow to adapt the volume with the engine / vehicle speed.

Very cool project sebastian - would definitely be interested in purchasing a cape and checkout out the firmware.


Man, you’ve been reading my thoughts and seeing my dreams. I was thinking the other day my MGB GT could benefit from something like this, and here it is.

I’m not much of a code monkey, so let me know when you have boards closer to release.


Sebastian how do you feed the analog amplifier? 150W is damn a lot

Hi - that’s correct - I am planning a CAN transceiver (Low speed CAN) for the next board revision.

Directly from the car battery / the existing car radio supply. As I integrated a Class-D amplifier instead of a Class-AB which is normally built-into existing car radios, I can get more audio output power from the same current consumption, e.g. a 10A current supply will give me ~120W audio output power, a 15A current supply up to 175W.
But remember: Normally you don’t need these high output power for a longer period (nobody listens to white noise or sinewaves for a longer period of time) - music is normally 10 times lower in terms of energy density.