Enable recording with four channels with Behringer UMC404HD sound card (#30)

* Enable recording with four channels with Behringer UMC404HD sound card

- Add udev rule to enable capture on 4 channels and set volume to max
- Move audio-recorder.nix to modules/audio-recorder/
- Update flake inputs

Signed-off-by: Satu Koskinen <satu.a.koskinen@gmail.com>

* Rename modules/audio-recorder/audio-recorder.nix to default.nix

Signed-off-by: Satu Koskinen <satu.a.koskinen@gmail.com>

---------

Signed-off-by: Satu Koskinen <satu.a.koskinen@gmail.com>

flake.lock

@@ -7,11 +7,11 @@
         "utils": "utils"
       },
       "locked": {
-        "lastModified": 1694158470,
-        "narHash": "sha256-yWx9eBDHt6WR3gr65+J85KreHdMypty/P6yM35tIYYM=",
+        "lastModified": 1694513707,
+        "narHash": "sha256-wE5kHco3+FQjc+MwTPwLVqYz4hM7uno2CgXDXUFMCpc=",
         "owner": "serokell",
         "repo": "deploy-rs",
-        "rev": "d0cfc042eba92eb206611c9e8784d41a2c053bab",
+        "rev": "31c32fb2959103a796e07bbe47e0a5e287c343a8",
         "type": "github"
       },
       "original": {
@@ -41,11 +41,11 @@
         "systems": "systems"
       },
       "locked": {
-        "lastModified": 1692799911,
-        "narHash": "sha256-3eihraek4qL744EvQXsK1Ha6C3CR7nnT8X2qWap4RNk=",
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "f9e7cf818399d17d347f847525c5a5a8032e4e44",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
         "type": "github"
       },
       "original": {
@@ -93,11 +93,11 @@
     },
     "nixos-hardware": {
       "locked": {
-        "lastModified": 1693718952,
-        "narHash": "sha256-+nGdJlgTk0MPN7NygopipmyylVuAVi7OItIwTlwtGnw=",
+        "lastModified": 1694591211,
+        "narHash": "sha256-NPP7XGZH+Q5ey7nE2zGLrBrzKmLYPhj8YgsTSdhH0D4=",
         "owner": "NixOS",
         "repo": "nixos-hardware",
-        "rev": "793de77d9f83418b428e8ba70d1e42c6507d0d35",
+        "rev": "3ccd87fcdae4732fe33773cefa4375c641a057e7",
         "type": "github"
       },
       "original": {
@@ -141,11 +141,11 @@
     },
     "nixpkgs_3": {
       "locked": {
-        "lastModified": 1694183432,
-        "narHash": "sha256-YyPGNapgZNNj51ylQMw9lAgvxtM2ai1HZVUu3GS8Fng=",
+        "lastModified": 1694422566,
+        "narHash": "sha256-lHJ+A9esOz9vln/3CJG23FV6Wd2OoOFbDeEs4cMGMqc=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "db9208ab987cdeeedf78ad9b4cf3c55f5ebd269b",
+        "rev": "3a2786eea085f040a66ecde1bc3ddc7099f6dbeb",
         "type": "github"
       },
       "original": {

flake.nix

@@ -39,7 +39,7 @@
         specialArgs = {inherit pkgs;};
         modules = [
           ./targets/raspberry-pi-4
-          ./modules/audio-recorder.nix
+          ./modules/audio-recorder
           ./modules/real-time-clock/i2c-rtc.nix
           ./modules/shutdown-button/service.nix
           nixos-hardware.nixosModules.raspberry-pi-4
@@ -53,7 +53,7 @@
         specialArgs = {inherit pkgs;};
         modules = [
           ./targets/raspberry-pi-3
-          ./modules/audio-recorder.nix
+          ./modules/audio-recorder
           ./modules/real-time-clock/i2c-rtc.nix
           hydrophonitor-gps.nixosModules.hydrophonitor-gps
           "${nixpkgs}/nixos/modules/installer/sd-card/sd-image-aarch64.nix"

modules/audio-recorder/default.nix

@@ -41,6 +41,14 @@
   };
 
   config = lib.mkIf config.services.audio-recorder.enable {
+    # Configure the Behringer UMC404HD to turn capture on for all four mics and set the mic volume to max
+    # Sound card idVendor and idProduct fields can be checked from /proc/asound/card1/usbid (when card number is 1, check with arecord -l)
+    services.udev.extraRules = ''
+      # Behringer Uphoria UMC404HD rules
+      # On connect, turn capture on for all mics and set the mic volume to max
+      SUBSYSTEMS=="usb", ATTRS{idVendor}=="1397", ATTRS{idProduct}=="0509", RUN+="${pkgs.writeShellScriptBin "umc404hd-autocapture" (builtins.readFile ./umc404hd-autocapture.sh)}"
+    '';
+
     systemd.services.audio-recorder = {
       description = "Audio Recording Service";
       wantedBy = ["multi-user.target"];

modules/audio-recorder/umc404hd-autocapture.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+# Enable capture and set input volume to 100% on all Behringer Uphoria 404HD inputs
+set -ex
+CARD=$(aplay -l | grep "USB Audio" | sed -e 's/^card\ \([0-9]\+\).*/\1/')
+amixer -c $CARD cset "name=Mic Capture Switch,index=0" 1,1,1,1
+amixer -c $CARD cset "name=Mic Capture Switch,index=1" 1
+amixer -c $CARD cset "name=Mic Capture Volume,index=0" 127,127,127,127
+amixer -c $CARD cset "name=Mic Capture Volume,index=1" 127

targets/raspberry-pi-4/default.nix

@@ -41,7 +41,7 @@ in {
     sample-rate = 192000;
     sample-format = "S32_LE";
     channels = 4;
-    max-file-time-secs = 300;
+    max-file-time-secs = 60;
   };
 
   services.gps-recorder = {