first setup of piano-visualizer on pianonix

hosts/pianonix/default.nix

@@ -88,6 +88,9 @@
       enable = true;
       overrideSettings = true;
     };
+    pianoLEDVisualizer = {
+      enable = true;
+    };
   };
 
   # Enable the Desktop Environment.
@@ -196,4 +199,39 @@
   # boot.loader.raspberryPi.firmwareConfig = ''
   #   dtparam=audio=on
   # '';
+
+  ## Enable SPI
+  hardware.raspberry-pi."4".apply-overlays-dtmerge.enable = true;
+  hardware.deviceTree = {
+    enable = true;
+    filter = "*-rpi-*.dtb";
+    overlays = [
+      {
+        name = "spi";
+        dtsoFile = ./spi0-0cd.dtso;
+      }
+    ];
+  };
+
+  users.groups.spi = {};
+
+  # services.udev.extraRules = ''
+  #   SUBSYSTEM=="spidev", KERNEL=="spidev0.0", GROUP="spi", MODE="0660"
+  # '';
+
+  ## Use GPIO as non-root
+  # Create gpio group
+  users.groups.gpio = {};
+
+  # Change permissions gpio devices
+  services.udev.extraRules = ''
+    SUBSYSTEM=="spidev", KERNEL=="spidev0.0", GROUP="spi", MODE="0660"
+
+    SUBSYSTEM=="bcm2835-gpiomem", KERNEL=="gpiomem", GROUP="gpio",MODE="0660"
+    SUBSYSTEM=="gpio", KERNEL=="gpiochip*", ACTION=="add", RUN+="${pkgs.bash}/bin/bash -c 'chown root:gpio /sys/class/gpio/export /sys/class/gpio/unexport ; chmod 220 /sys/class/gpio/export /sys/class/gpio/unexport'"
+    SUBSYSTEM=="gpio", KERNEL=="gpio*", ACTION=="add",RUN+="${pkgs.bash}/bin/bash -c 'chown root:gpio /sys%p/active_low /sys%p/direction /sys%p/edge /sys%p/value ; chmod 660 /sys%p/active_low /sys%p/direction /sys%p/edge /sys%p/value'"
+  '';
+
+  # Add user to group
+  users.users.julian.extraGroups = ["gpio"];
 }