Si4703 extended volume range

[fjansson]

The Si4703 has a configuration bit for extending the volume range, essentially offering 16 additional lower volume levels. Would it be possible to add support for setting this bit? I find the lowest regular volume setting uncomfortably loud on the Si4703 breakout board I have (sparkfun clone).

The bit is called VOLEXT and is present in register 06 = SYSCONFIG3. My suggestion would be to offer more audio level settings and handle the VOLEXT bit in the setVolume function.