I began mapping the ALSA device names into english terms that describe the physical connections on the board. My list is incomplete though I think it would be quick to improve with more eyes. Here is what I have so far. Some may be incorrect.
To get a list output to your screen of all devices on the card, type this:
amixer -Dhw:0 controls
There are 542 controls. Which is totally cool. But quite the adventure when the goal is to do something like "record sound" in less than an 8 hour hacking session.
| ALSA Device Name | English Name |
|---|---|
| HPOUT1 | Headphone Output (Black 3.5mm jack) |
| HPOUT2 | Line Out (Green 3.5mm jack) |
| SPDIF | S/PDIF related controls (Orange and White RCA jacks) |
| AIF | DAC/ADC related controls to interface with the RPi |
| Headset Mic | Headphone mic (Black 3.5mm jack with TRS cable) |
| EPOUT | |
| DRE | |
| Mic Input | |
| DSP | |
| ASRC | |
| DMIC | On board stereo microphones |
| DRC | |
| High Performance | 24bit/192khz recording |
| IN3 | Line In (Pink 3.5mm jack) |
| SLIM | |
| LHPF | Low/High Pass Filter |
| ISRC | |
| PWM | |
| EQ | Parametric Equalizer controls |