{
  description = "Wearables";

  inputs = {
    nixpkgs.url = "nixpkgs/nixos-21.11";
  };

  outputs = { self, nixpkgs }:
    let 
      version = builtins.string 0 8 self.lastModifiedDate;
      supportedSystems = [ "x86_64-linux" "avr-none" ];
    in
    {
      /*
      packages.base."x86_64-linux" =
        let pkgs = import nixpkgs { system = "x86_64-linux"; };
        in pkgs.stdenv.mkDerivation rec {
          name = "wearables-base";
          src = "./base";

          installPhase = ''
            mkdir -p $out/include
            cp include/base.h $out/include
            '';
        };
        */

      defaultPackage."x86_64-linux" =
        let
          pkgs = import nixpkgs { system = "x86_64-linux"; };
          avr = pkgs.pkgsCross.avr.buildPackages;
        in pkgs.stdenv.mkDerivation rec {
          name = "pwm";
          src = ./.;

          buildInputs = [ pkgs.simavr ];

          MCU = "attiny85";
          CHIP_SELECT = "AVR_ATtiny85";
          F_CPU = "8000000";
          CFLAGS = ''-O -finline-functions -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -Wall -Wstrict-prototypes -DF_CPU=${F_CPU} -std=gnu99 -D__${CHIP_SELECT}__=1 -mmcu=${MCU}'';

          buildPhase = ''
            ${avr.gcc}/bin/avr-gcc ${CFLAGS} -I${src}/base/include/ -E -o main.post-cc ${src}/pwm/src/main.c
            ${avr.gcc}/bin/avr-gcc ${CFLAGS} -I${src}/base/include/ -o main.elf ${src}/pwm/src/main.c
            $OBJCOPY -O ihex main.elf main.hex
            '';
          installPhase = ''
            mkdir $out
            cp main.post-cc $out
            cp main.elf main.hex $out
            '';
        };

      devShell."x86_64-linux" =
        let
          pkgs = import nixpkgs { system = "x86_64-linux"; };
          avr = with pkgs.pkgsCross.avr.buildPackages; [
            binutils
            gcc
            avrdude
            simavr
          ];
        in
        pkgs.mkShell {
          name = "Wearables-shell";
          buildInputs = avr;
        };
    };
}