The development of Giesemann Rosanna Network Bridge x Raspberry Pi5 x OCXO x I2S HDMI Edition

The development of Giesemann Rosanna Network Bridge x Raspberry Pi5 x OCXO x I2S HDMI Edition 

As you may know, AfterDark. is founded by developing the very first product with Raspberry Pi3+ 1G. We start up the business in a very very small scale, which Adrian is working alone after dark after his daily rountine job in financial industry lately. We found that Raspberry Pi is very interesting product with a lot of combination of sounding with different setup and we gathered a lot of information form audiophiles and start to optimised the sounding in respect to a very unique motherboard from Raspberry Pi3 developed to use in various applications, in very low cost and opensource linux based OS developements.

Then we developed a ultra low noise LPS, a GPIO DC Cable for direct connection to the motherboard, USB cable, Lan Cable, using digital HAT card, adding different Audio Grade Capacitor for sound tuning and we developed a very interesting customer base locally and get some awareness on our very first audio product for all audiophiles. 

This is the very first Pi3 we developed. The copper foil is used for shielding. 

This is surprised for us, we developed a different model of Raspberry Pi3+ 1GB,  Pi4 4GB to the latest Pi5 8GB. The concept has not changed and we hears the sounding is improving from each stage, this is because of developement of CPU, USB, and LAN chips. 

What is I2S?
I2S (Inter-IC Sound Bus) is a bus standard developed by Philips for audio data transmission between digital audio devices. In Philips' I2S standard, it stipulates not only the hardware interface specification, but also the format of digital audio data.

I2S has 3 main signals:

• The serial clock SCLK, also called the bit clock (BCLK), corresponds to each bit of digital audio data, SCLK has one pulse. SCLK frequency = 2 × sampling frequency × number of sampling bits
• The frame clock LRCK is used to switch the data of the left and right channels. If LRCK is "1", it means that the data of the left channel is being transmitted, and if it is "0", it means that the data of the right channel is being transmitted. The frequency of LRCK is equal to the sampling frequency.
• Serial data SDATA is audio data represented by two's complement.

The standard GPIO interface on Raspberry Pi make it very flexible for software and hardware developer to have access the I2S signal for developing different kind of audio HAT. 

TBC.  

This version is made to order for customer to use it on his audiophile system inside the car. 

The native i2S signal will be extracted via GPIO interface on the motherboard