The front panel buttons/knob are working pretty good now. It seems like the knob has a bit too aggressive debounce on it, as spinning fast seems to drop out. It's understandable though with the mechanical rotary encoder, it's just that the squeezeboxserver has some velocity sensitive stuff that's pretty nice but if I try to get it to kick in the knob is holding me back.

Next up is the DSP equalizer. I've figured out how to read/write it, but I can't find information on how to calculate the constants. I've searched both the 7705 datasheet and user guide but it doesn't seem to have these. I can kind of figure out how to stuff the freq, Q, and gain into word1 and word2 but I don't know how to calculate the actual constants.