RasPi3b+ OctoPrint config with GPIO

configuration.nix

{ config, pkgs, lib, ... }:
{
  imports = [
    ./hardware-configuration.nix
    ./update-uboot.nix
    ./secrets.nix # Only sets `services.octoprint.extraConfig.api.key`
    ./octoprint.nix
  ];

  boot.kernelPackages = pkgs.linuxKernel.packages.linux_rpi3;
  boot.kernelParams = [ "cma=256M" ];

  boot.loader.raspberryPi.enable = true;
  boot.loader.raspberryPi.version = 3;
  boot.loader.raspberryPi.uboot.enable = true;
  boot.loader.raspberryPi.firmwareConfig = ''
    gpu_mem=256
  '';
  boot.loader.grub.enable = false;
  boot.loader.generic-extlinux-compatible.enable = true;
  boot.extraModprobeConfig = ''
    options cf680211 ieee80211_regdom="DE"
  '';

  hardware.enableRedistributableFirmware = true;
  hardware.firmware = [ pkgs.wireless-regdb ];

  networking.hostName = "octonix"; # Define your hostname.
  networking.wireless = {
    enable = false;
    interfaces = [ "wlan0" ];
  };

  environment.systemPackages = with pkgs; [ libraspberrypi libgpiod ];

  networking.useDHCP = false;
  networking.interfaces.eth0.useDHCP = true;
  networking.interfaces.wlan0.useDHCP = true;

  users.groups."gpio" = { };

  services.udev.extraRules = ''
    SUBSYSTEM=="gpio", KERNEL=="gpiochip*", GROUP="gpio", MODE="0660"
  '';

  system.stateVersion = "21.05";

}

hardware-configuration.nix

{ config, lib, pkgs, modulesPath, ... }:
{
  imports = [ (modulesPath + "/installer/scan/not-detected.nix") ];
  boot.initrd.includeDefaultModules = false; # Needed because the ahci module is not available for _rpi* kernel
  boot.initrd.availableKernelModules = [ "usbhid" "mmc_block" ];
  boot.initrd.kernelModules = [ ];
  boot.kernelModules = [ ];
  boot.extraModulePackages = [ ];

  fileSystems."/" = {
    device = "/dev/disk/by-label/NIXOS_SD";
    fsType = "ext4";
  };

  swapDevices = [ ];

  powerManagement.cpuFreqGovernor = lib.mkDefault "ondemand";
}

octoprint.nix

{ config, pkgs, lib, ... }: {
# TODO: Split file
  networking.firewall = {
    allowedTCPPorts = [ config.services.octoprint.port 5050 ];
  };
  
  systemd.services.octoprint = {
    path = [ pkgs.libraspberrypi ];
    serviceConfig.AmbientCapabilities = [ "CAP_NET_BIND_SERVICE" ];
  };
  
  users.users.octoprint.extraGroups = [ "gpio" "dialout" ];
  
  services = {
    octoprint = {
      enable = true;
      port = 80;

      extraConfig = {
        serial = {
          port = "/run/klipper/tty";
          baudrate = "250000";
          autoconnect = true;
          disconnectOnErrors = false;
        };
        plugins = {
          pi_support = {
            vcgencmd_throttle_check_command =
              "${pkgs.libraspberrypi}/bin/vcgencmd get_throttled";
          };
          dashboard = { showWebCam = true; };
          psucontrol = {
            autoOn = true;
            disconnectOnPowerOff = true;
            enablePseudoOnOff = true;
            offSysCommand = "${pkgs.libgpiod}/bin/gpioset -l 0 4=0";
            onSysCommand = "${pkgs.libgpiod}/bin/gpioset -l 0 4=1";
            postOnDelay = "2";
            switchingMethod = "SYSTEM";
          };
          marlingcodedocumentation = {
            include_source_reprap = false;
            show_sources_checkboxes = false;
          };
        };
        webcam = {
          snapshot = "http://127.0.0.1:5050/?action=snapshot";
          stream = "http://192.168.10.6:5050/?action=stream";
        };
        temperatures.profiles = [
          {
            name = "PETG";
            extruder = 230;
            bed = 80;
            chamber = 0;
          }
          {
            name = "PLA";
            extruder = 180;
            bed = 60;
            chamber = 0;
          }
        ];
      };

      plugins = p:
        with p; [
          abl-expert
          displayprogress
          displaylayerprogress
          marlingcodedocumentation
          titlestatus
          octoprint-dashboard

          psucontrol
          printtimegenius

          octoklipper

          (buildPlugin rec {
            pname = "FirmwareUpdater";
            version = "1.12.0";

            src = pkgs.fetchFromGitHub {
              owner = "OctoPrint";
              repo = "OctoPrint-${pname}";
              rev = version;
              sha256 = "1xjxjblxvqzqb5nn4ixygyzmxcw2wl5c2zdzfxx4xr26adq2dhhq";
            };

            meta = with pkgs.lib; {
              description =
                "The Firmware Updater plugin can be used to flash pre-compiled firmware images to your printer from a local file or URL.";
              homepage =
                "https://github.com/OctoPrint/OctoPrint-FirmwareUpdater#supported-boards";
              license = licenses.agpl3Plus;
            };
          })

          (buildPlugin rec {
            pname = "BedLevelingWizard";
            version = "0.2.4";

            src = pkgs.fetchFromGitHub {
              owner = "jneilliii";
              repo = "OctoPrint-${pname}";
              rev = version;
              sha256 = "149rnkvqvjxgxv99sqjmkw3w4jmlz8mr25c7rsyyamgcjbl0w663";
            };

            meta = with pkgs.lib; {
              description =
                "This plugin implements a guided leveling approach to manual bed leveling.";
              homepage =
                "https://github.com/jneilliii/OctoPrint-BedLevelingWizard";
            };
          })

          (buildPlugin rec {
            pname = "CalibrationCompanion";
            version = "1.0.1";

            src = pkgs.fetchFromGitHub {
              owner = "iFrostizz";
              repo = "OctoPrint-${pname}";
              rev = version;
              sha256 = "1abx7h7fzcdmrgmp01b91gaqig5dh84rrjx0gh9fpy12a197nv6w";
            };

            meta = with pkgs.lib; {
              description =
                "This plugin was created to calibrate 3D printer settings easily.";
              homepage =
                "https://github.com/iFrostizz/OctoPrint-CalibrationCompanion";
            };
          })

          (buildPlugin rec {
            pname = "BedLevelVisualizer";
            version = "1.1.0";

            src = pkgs.fetchFromGitHub {
              owner = "jneilliii";
              repo = "OctoPrint-${pname}";
              rev = version;
              sha256 = "1ixm780n631wy4xp0m3kfvrq53yxghn5s0k51vdyn3mj66sy3aj8";
            };

            propagatedBuildInputs = with pythonPackages; [ numpy flask ];

            meta = with pkgs.lib; {
              description = "Displays 3D mesh of bed topography report";
              homepage =
                "https://github.com/jneilliii/OctoPrint-BedLevelVisualizer";
              license = licenses.agpl3;
            };
          })

          (buildPlugin rec {
            pname = "GCodeSystemCommands";
            version = "1.0.1";

            src = pkgs.fetchFromGitHub {
              owner = "kantlivelong";
              repo = "OctoPrint-GCodeSystemCommands";
              rev = "${version}";
              sha256 = "07nvc5l0q9n7cbdrw40ljkwv9b85d2kpbh3ziza1f28mh6y7iszg";
            };

            meta = with pkgs.lib; {
              description =
                "This OctoPrint plugin adds the ability to define GCode commands that execute local system commands.";
              homepage =
                "https://github.com/kantlivelong/OctoPrint-GCodeSystemCommands";
              license = licenses.agpl3Only;
            };
          })
        ];
    };

    mjpg-streamer = { enable = true; };

    klipper = {
      enable = true;
      octoprintIntegration = config.services.octoprint.enable;
      settings = let
        rotDist =
          { steps_per_mm, microsteps ? 16, full_steps_per_rotation ? 200 }:
          (full_steps_per_rotation * microsteps / steps_per_mm);
        buildMultiLineStr = l: "\n    " + lib.concatStringsSep "\n    " l;
      in {
        mcu = {
          serial =
            "/dev/serial/by-id/usb-Klipper_stm32f103xe_33FFDB054E43383415522043-if00";
        };

        printer = {
          kinematics = "cartesian";
          max_velocity = 300;
          max_accel = 3000;
          max_z_velocity = 5;
          max_z_accel = 100;
        };

        "static_digital_output usb_pullup_enable" = { pins = "!PC13"; };

        board_pins = {
          aliases = ''
            EXP1_1=PA15, EXP1_3=PA9,   EXP1_5=PA10, EXP1_7=PB8, EXP1_9=<GND>, EXP1_2=PB6,  EXP1_4=<RST>, EXP1_6=PB9,  EXP1_8=PB7, EXP1_10=<5V>
          '';
        };

        display = {
          lcd_type = "st7920";
          cs_pin = "EXP1_7";
          sclk_pin = "EXP1_6";
          sid_pin = "EXP1_8";
          encoder_pins = "^EXP1_5, ^EXP1_3";
          click_pin = "^!EXP1_2";
        };
        "output_pin beeper".pin = "EXP1_1";

        fan.pin = "PA8";

        gcode_arcs.resolution = 1.0;

        heater_bed = {
          heater_pin = "PC9";
          sensor_type = "EPCOS 100K B57560G104F";
          sensor_pin = "PC3";
          control = "pid";
          # PID-Tuning with
          # $ PID_CALIBRATE HEATER=heater_bed TARGET=80
          pid_Kp = 66.136;
          pid_Ki = 1.263;
          pid_Kd = 865.552;
          min_temp = 0;
          max_temp = 90;
        };

        extruder = {
          step_pin = "PB0";
          dir_pin = "!PC5";
          enable_pin = "!PB1";
          microsteps = "16";
          nozzle_diameter = "0.400";
          filament_diameter = "1.750";
          heater_pin = "PC8";
          sensor_type = "NTC 100K beta 3950";
          sensor_pin = "PA0";
          control = "pid";

          rotation_distance = rotDist { steps_per_mm = 100.2; };

          pid_Kp = 11.56;
          pid_Ki = 0.72;
          pid_Kd = 46.32;

          min_temp = 0;
          max_temp = 260;
        };

        "tmc5160 extruder" = {
          cs_pin = "PD2";
          run_current = 0.7;
          hold_current = 0.5;
          stealthchop_threshold = 999999;
          spi_bus = "spi3";
          sense_resistor = 7.5e-2;
        };

        stepper_x = {
          step_pin = "PC6";
          dir_pin = "!PB15";
          enable_pin = "!PC7";
          microsteps = 16;
          rotation_distance = rotDist { steps_per_mm = 80; };
          endstop_pin = "tmc5160_stepper_x:virtual_endstop";
          position_min = -20;
          position_endstop = -20;
          position_max = 235;
          homing_speed = 30;
        };

        "tmc5160 stepper_x" = {
          cs_pin = "PC10";
          run_current = 0.6;
          hold_current = 0.4;
          stealthchop_threshold = 999999;
          spi_bus = "spi3";
          sense_resistor = 7.5e-2;
          driver_SGT = 5; # Sensitivity
          diag1_pin = "^!PC1";
        };

        stepper_y = {
          step_pin = "PB13";
          dir_pin = "!PB12";
          enable_pin = "!PB14";
          microsteps = 16;
          rotation_distance = rotDist { steps_per_mm = 80.523; };
          endstop_pin = "tmc5160_stepper_y:virtual_endstop";
          position_min = -38;
          position_endstop = -38;
          position_max = 190;
          homing_speed = 30;
        };

        "tmc5160 stepper_y" = {
          cs_pin = "PC11";
          run_current = 0.6;
          hold_current = 0.4;
          stealthchop_threshold = 999999;
          spi_bus = "spi3";
          sense_resistor = 7.5e-2;
          driver_SGT = 5; # Sensitivity
          diag1_pin = "^!PC0";
        };

        stepper_z = {
          step_pin = "PB10";
          dir_pin = "PB2";
          enable_pin = "!PB11";
          microsteps = 16;
          rotation_distance = rotDist { steps_per_mm = 400; };
          endstop_pin = "^PC15";
          position_endstop = 0;
          #endstop_pin = "probe:z_virtual_endstop";
          #position_min = -3;
          position_max = 200;
        };

        "tmc5160 stepper_z" = {
          cs_pin = "PC12";
          run_current = 0.6;
          hold_current = 0.4;
          stealthchop_threshold = 999999;
          spi_bus = "spi3";
          sense_resistor = 7.5e-2;
          driver_SGT = 6; # Sensitivity
        };

        pause_resume = { };

        "gcode_macro PARK" = {
          gcode = buildMultiLineStr [
            "G91"
            "G1 E-30 F2100"
            "G1 Z10"
            "G90"
            "G1 X-15 Y-20 F6000"
          ];
        };
        "gcode_macro FILAMENT_LOAD" = {
          gcode = buildMultiLineStr [ "G91" "G1 E49 F500" "G90" ];
        };

        "gcode_macro FILAMENT_UNLOAD" = {
          gcode = buildMultiLineStr [
            "G91"
            "G1 E0.5 F1000"
            "G1 E-0.5 F1000"
            "G1 E1.0 F1000"
            "G1 E-1.0 F1000"
            "G1 E1.5 F1000"
            "G1 E-1.5 F1000"
            "G1 E2.0 F1000"
            "G1 E-2 F500"
            "G1 E-49 F3000"
            "G90"
          ];
        };

        "gcode_macro M600" = {
          gcode = buildMultiLineStr [
            "SAVE_GCODE_STATE NAME=M600_state"
            "PARK"
            "FILAMENT_UNLOAD"
            "PAUSE" # Swap filament here, then do FILAMENT_LOAD and RESUME
            "FILAMENT_LOAD"

            "G91"
            "G1 Z-10"
            "G90"

            "RESTORE_GCODE_STATE NAME=M600_state"
          ];
        };
      };
    };
  };
}

update-uboot.nix

{ pkgs, ... }: {
  fileSystems."/boot/firmware" = {
    device = "/dev/disk/by-label/FIRMWARE";
    fsType = "vfat";
  };

  systemd.services."uboot-updater" = {
    enable = true;
    description = "u-boot updater";

    wantedBy = [ "multi-user.target" ];
    after = [ "multi-user.target" "boot-firmware.mount" ];
    serviceConfig.Type = "oneshot";

    path = [ pkgs.diffutils ];
    script = ''
      CURRENT="/boot/firmware/u-boot-rpi3.bin"
      UPDATE="${pkgs.ubootRaspberryPi3_64bit}/u-boot.bin"

      cmp --silent -- "$CURRENT" "$UPDATE"; 
      if [ "$?" == "1" ]; then
        echo "Updating u-boot with $UPDATE";
        cp -v -- "$UPDATE" "$CURRENT";
      else
        echo "No update required (Version: ${
          toString pkgs.ubootRaspberryPi3_64bit.version
        })"
      fi
    '';
  };
}