I am planning to use the very cheap PT8211 DAC. It is a 16Bit DAC with mediocre performance but I believe it is better than the RPi analog audio and it costs only a few cents.
Currently I am stuck. I found some info at github.com/raspberrypi/linux/tr … nd/soc/bcm
and it seems in essence that copy&paste e.g. hifiberry_dac.c and minor adaptations are sufficient. But I am missing the environment and the source to compile the backend of volumio and I might mistaken with my approach. So any feedback and information are very welcome.
PT8211 From the documentation
PT8211 can be supported wide range of sample frequency, it is compatible with TDA1311 by
functionally. It’s digital input timing format is Least Significant Bit Justified (LSBJ), or so called
Japanese input format. Digital code format is two’s complement and MSB first. PT8211 is available in
8-pin SOP or DIP.
The serial bus input data format ofPT8211 is Japanese or called LSBJ (Least Significant Bit Justified)
format. Each valid DIN data will be shifted to the inputregister in the rising edge of the BCK, only the
first 16bit data ( from MSB) is valid if the input data length is more than 16bits, other data bit will be
truncated. The clock frequency of the BCK could run up to 20MHz and supported to 8× over-sampling
in 48KHz WS clock rate. Both left and right data words are time multiplexed. Please refer to the
diagrams for timing and input signal formats.