mic mute button

README.md

@@ -310,6 +310,17 @@ Only external microphones work.
 Mic in browser didn't work, but then it started to work at some point,
 without me seemingly changing anything.
 
+#### Mic mute button
+
+Create `/etc/acpi/events/lenovo-mutemic` with the following content:
+```
+event=button/micmute MICMUTE 00000080 00000000 K
+action=amixer --card 1 set 'Capture' toggle
+```
+where card number is the one obtained in previous section; and event could be determined by running `acpi_listen` and pressing mic button.
+
+Then, after `doas rc-service acpid restart`, mic button should control internal mic capture in alsa and switch internal mic led on and off.
+
 ### Webcam
 
 Should work after following the steps for "Audio".