Initial scaffold: NixOS + SvelteKit dashboard + Python renderer

2026-06-07 18:15:06 +02:00
commit 50256fa384
25 changed files with 4491 additions and 0 deletions
@@ -0,0 +1,54 @@
+{ config, lib, pkgs, modulesPath, ... }:
+
+{
+  # Pi 4 aarch64. Boot from the official NixOS sd-image; we don't generate
+  # the image from this flake — flash the upstream aarch64 sd-image once,
+  # then `nixos-rebuild switch --flake .#dayplanner --target-host` swaps
+  # the running system over and comin takes over from there.
+  imports = [
+    "${modulesPath}/installer/sd-card/sd-image-aarch64.nix"
+  ];
+
+  # Drop the default channel; we deploy from the flake.
+  sdImage.compressImage = false;
+
+  boot.loader.grub.enable = false;
+  boot.loader.generic-extlinux-compatible.enable = true;
+
+  # The Waveshare 12.48" HAT is driven entirely from userspace Python via
+  # /dev/spidev*. We only need SPI enabled in the device tree and the
+  # gpio/spi groups available to the renderer user.
+  boot.kernelParams = [ "console=serial0,115200" "console=tty1" ];
+
+  # Enable SPI0 (CE0/CE1) and the extra GPIOs the HAT needs.
+  # See: https://www.waveshare.com/wiki/12.48inch_e-Paper_Module
+  hardware.deviceTree = {
+    enable = true;
+    overlays = [
+      {
+        name = "spi-on";
+        dtsText = ''
+          /dts-v1/;
+          /plugin/;
+          / {
+            compatible = "brcm,bcm2711";
+            fragment@0 {
+              target = <&spi0>;
+              __overlay__ {
+                status = "okay";
+              };
+            };
+          };
+        '';
+      }
+    ];
+  };
+
+  users.groups.spi = {};
+  users.groups.gpio = {};
+
+  services.udev.extraRules = ''
+    SUBSYSTEM=="spidev", GROUP="spi", MODE="0660"
+    SUBSYSTEM=="gpio", GROUP="gpio", MODE="0660"
+  '';
+}