Audio output over Inter-IC Sound (I²S)
Inter-IC Sound (I²S) is another type of data interface but for audio. Essentially, it has three lines for the following:
- Data, Data-In (DIN), or Data-Out (DOUT)
- Clock or bit clock (BCLK)
- Channel select, Word Select (WS), or Left-Right Clock (LRCLK)
The interface is standard; however, the naming is not, as we see above. The data line carries stereo audio data for both the left (channel 0) and right (channel 1) channels. The channel select signal level indicates which channel’s data is currently being transferred: it is low for the left channel and high for the right channel. Finally, the clock line is a common clock for both ends provided by the master, which is usually the sending party in this type of communication.
In audio projects, we normally need a Digital-Analog Converter (DAC) to convert digital audio data to its analog counterpart and an amplifier to forward the analog output to a...
