Update the flake

Add some bounding boxes to keep the animation doing something like the right thing

animation/animation.c

@@ -1,6 +1,17 @@
 #include "animation.h"
 #include <stdio.h>
 
+int bound(int value, uint8_t min, uint8_t max) {
+    if (value > max) {
+        return max;
+    } else if (value < min) {
+        return min;
+    } else {
+        return value;
+    }
+}
+
+
 time_line_t time_line_new(int t0, int y0, int t1, int y1) {
     int dt = t1 - t0;
     int dy = y1 - y0;
@@ -15,7 +26,7 @@ time_line_t time_line_new(int t0, int y0, int t1, int y1) {
         error = de + dt;
     }
 
-    return (time_line_t){ .y = y0, .dt = dt, .de = de, .error = error, .inc = inc, .dy = dy };
+    return (time_line_t){ .y = y0, .dt = dt, .de = de, .error = error, .inc = inc, .dy = dy, .y0 = y0, .y1 = y1 };
 }
 
 int time_line_next(time_line_t *self) {
@@ -28,11 +39,17 @@ int time_line_next(time_line_t *self) {
         }
     } else {
         while (error < 0) {
-            self->y -= self->inc;
+            self->y += self->inc;
             error += 2 * self->dt;
         }
     }
 
+    if (self->y0 < self->y1) {
+        self->y = bound(self->y, self->y0, self->y1);
+    } else {
+        self->y = bound(self->y, self->y1, self->y0);
+    }
+
     self->error = error;
     return self->y;
 }

animation/animation.h

@@ -1,3 +1,6 @@
+
+#include <stdint.h>
+
 #ifndef __ANIMATION_H__
 #define __ANIMATION_H__
 
@@ -12,6 +15,8 @@ typedef struct {
     int inc;
     int dt;
     int dy;
+    int y0;
+    int y1;
 } time_line_t;
 
 // Construct a new line object. x1 must be greater than x0, and dy must be less than dx.
@@ -21,6 +26,6 @@ time_line_t time_line_new(int, int, int, int);
 int time_line_next(time_line_t *);
 
 // Diagnostic printout of the current state of line_t.
-// void line_print(line_t *line);
+void time_line_print(time_line_t *);
 
 #endif

animation/bresenham.c

@@ -1,32 +0,0 @@
-#include <stdlib.h>
-
-void bresenham_time(int t1, int y1, int t2, int y2) {
-    int dt = t2 - t1;
-    int dy = y2 - y1;
-    int m = 2 * dy;
-    int err = 0;
-
-    if (m > 0) {
-        err = m - dt;
-    } else if (m < 0) {
-        err = m + dt;
-    }
-    for (int t = t1, y = y1; t <= t2; t++) {
-        printf("(%d, %d) [%d]\n", t, y, err);
-
-        err += m;
-
-        if (m > 0) {
-            if (err >= 0) {
-                y++;
-                err -= 2 * dt;
-            }
-        } else if (m < 0) {
-            if (err <= 0) {
-                y--;
-                err += 2 * dt;
-            }
-        }
-    }
-}
-

animation/main.c

@@ -1,36 +0,0 @@
-#include <stdlib.h>
-#include <stdio.h>
-#include <animation.h>
-
-int main (void) {
-    {
-        time_line_t line = time_line_new(0, 0, 15, 10);
-        time_line_print(&line);
-        for (int i = 0; i < 15; i++) {
-            time_line_next(&line);
-            time_line_print(&line);
-        }
-    }
-
-    printf("\n");
-
-    {
-        time_line_t line = time_line_new(0, 0, 15, 25);
-        time_line_print(&line);
-        for (int i = 0; i < 15; i++) {
-            time_line_next(&line);
-            time_line_print(&line);
-        }
-    }
-
-    printf("\n");
-
-    {
-        time_line_t line = time_line_new(0, 0, 10, 255);
-        time_line_print(&line);
-        for (int i = 0; i < 10; i++) {
-            time_line_next(&line);
-            time_line_print(&line);
-        }
-    }
-}

dio/dio.h

@@ -3,11 +3,11 @@ Copyright 2022, Savanni D'Gerinel <savanni@luminescent-dreams.com>
 
 This file is part of Savanni's AVR library.
 
-Lumeto is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+This AVR library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
 
-Lumeto is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+This AVR library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 
-You should have received a copy of the GNU General Public License along with Lumeto. If not, see <https://www.gnu.org/licenses/>.
+You should have received a copy of the GNU General Public License along with this AVR library. If not, see <https://www.gnu.org/licenses/>.
 */
 
 #ifndef __BASE_H__
@@ -51,7 +51,7 @@ inline void dio_set(dio_t *line, bool value) {
     }
 }
 
-inline int dio_read(dio_t *line) {
+inline uint8_t dio_read(dio_t *line) {
     return (*(line->pin) & _BV(line->addr)) > 0;
 }
 

display/display.c

@@ -3,14 +3,14 @@ Copyright 2022, Savanni D'Gerinel <savanni@luminescent-dreams.com>
 
 This file is part of Savanni's AVR library.
 
-Lumeto is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+This AVR library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
 
-Lumeto is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+This AVR library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 
-You should have received a copy of the GNU General Public License along with Lumeto. If not, see <https://www.gnu.org/licenses/>.
+You should have received a copy of the GNU General Public License along with this AVR library. If not, see <https://www.gnu.org/licenses/>.
 */
 
-#include <base.h>
+#include <dio.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <util/delay.h>

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1649944829,
+        "lastModified": 1659446231,
-        "narHash": "sha256-wjOgLfjCdyoRamMOrVJceeDJk4LvJsQOxBoT3k16/7Q=",
+        "narHash": "sha256-hekabNdTdgR/iLsgce5TGWmfIDZ86qjPhxDg/8TlzhE=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "2f06b87f64bc06229e05045853e0876666e1b023",
+        "rev": "eabc38219184cc3e04a974fe31857d8e0eac098d",
         "type": "github"
       },
       "original": {

flake.nix

@@ -9,413 +9,279 @@
     let 
       version = builtins.string 0 8 self.lastModifiedDate;
       supportedSystems = [ "x86_64-linux" "avr-none" ];
-      cflags = { mcu, chip_select, f_cpu }: ''-O -finline-functions -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -Wall -Werror -Wstrict-prototypes -DF_CPU=${f_cpu} -std=gnu99 -D__${chip_select}__=1 -mmcu=${mcu}'';
+      mcu_cflags = { mcu, chip_select, f_cpu }: ''-O -finline-functions -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -Wall -Werror -Wstrict-prototypes -DF_CPU=${f_cpu} -std=gnu99 -D__${chip_select}__=1 -mmcu=${mcu}'';
 
       attiny85 = { mcu = "attiny85"; chip_select = "AVR_ATtiny85"; f_cpu = "8000000"; };
       atmega32u4 = { mcu = "atmega32u4"; chip_select = "AVR_ATmega32u4"; f_cpu = "8000000"; };
-      processor = atmega32u4;
+
+      mkLibrary = { pkgs, gcc, cflags, pname, psrc, pbuildInputs ? [] }:
+      pkgs.stdenv.mkDerivation rec {
+        name = pname;
+        src = psrc;
+
+        buildInputs = pbuildInputs;
+
+        include_dirs = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}/include") buildInputs);
+        object_files = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
+
+        dontUnpack = true;
+        dontConfigure = true;
+
+        buildPhase = ''
+          for source in ${src}/*.c; do
+              if [ -e $source ]; then
+                  ${gcc} ${cflags} ${include_dirs} -c $source
+              fi
+          done
+          cp ${src}/*.h . || true
+          '';
+
+        installPhase = ''
+          mkdir -p $out/include $out/lib
+          cp *.h $out/include || true
+          cp *.o $out/lib || true
+          '';
+      };
+
+      mkProgram = { pkgs, gcc, cflags, pname, psrc, pbuildInputs ? [], avr ? false }:
+      let
+        AVR = if avr == true then "1" else "";
+      in pkgs.stdenv.mkDerivation rec {
+        name = pname;
+        src = psrc;
+
+        buildInputs = pbuildInputs;
+
+        include_dirs = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}/include") buildInputs);
+        object_files = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/lib/*.o") buildInputs);
+
+        dontUnpack = true;
+        dontConfigure = true;
+
+        buildPhase = ''
+          for source in ${src}/*.c; do
+              if [ -e $source ]; then
+                  ${gcc} ${cflags} ${include_dirs} -c $source
+              fi
+          done
+
+          ${gcc} -o ${name}.elf ${cflags} ${object_files} *.o
+          if $AVR; then
+            $OBJCOPY -O ihex ${name}.elf ${name}.hex
+          fi
+          '';
+
+        installPhase = ''
+          mkdir -p $out/bin
+          cp ${name}.elf ${name}.hex $out/bin
+          '';
+      };
+
     in rec
     {
       defaultPackage."x86_64-linux" = 
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
+          avr = pkgs.pkgsCross.avr.buildPackages;
         in pkgs.symlinkJoin {
           name = "avr-monorepo";
           paths = [
-            (packages."x86_64-linux"."flame" processor)
+            (packages."x86_64-linux"."prime-tx" { gcc = "${avr.gcc}/bin/avr-gcc"; cflags = mcu_cflags atmega32u4; })
-            (packages."x86_64-linux"."prime-tx" processor)
+            (packages."x86_64-linux"."radio-rx" { gcc = "${avr.gcc}/bin/avr-gcc"; cflags = mcu_cflags atmega32u4; })
-            (packages."x86_64-linux"."radio-rx" processor)
+            (packages."x86_64-linux"."lantern" { gcc = "${avr.gcc}/bin/avr-gcc"; cflags = mcu_cflags atmega32u4; avr = true; })
-            (packages."x86_64-linux"."interrupts" processor)
+            (packages."x86_64-linux"."lantern-controller" { gcc = "${avr.gcc}/bin/avr-gcc"; cflags = mcu_cflags atmega32u4; avr = true; })
           ];
         };
 
-      packages."x86_64-linux"."base-attiny85" = (packages."x86_64-linux"."base" attiny85);
+      packages."x86_64-linux"."dio" =
-
+        { gcc, cflags }:
-      packages."x86_64-linux"."base" =
-        { mcu, chip_select, f_cpu }:
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
-          avr = pkgs.pkgsCross.avr.buildPackages;
+        in mkLibrary {
-        in pkgs.stdenv.mkDerivation rec {
+          pkgs = pkgs;
-          name = "base";
+          gcc = gcc;
-          src = ./.;
+          cflags = cflags;
-
+          pname = "dio";
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
+          psrc = ./dio;
-
-          installPhase = ''
-            mkdir $out
-            cp base/base.h $out/
-            '';
-        };
-
-      packages."x86_64-linux"."rng" =
-        { mcu, chip_select, f_cpu }:
-        let
-          pkgs = import nixpkgs { system = "x86_64-linux"; };
-          avr = pkgs.pkgsCross.avr.buildPackages;
-        in pkgs.stdenv.mkDerivation rec {
-          name = "rng";
-          src = ./.;
-
-          buildInputs = [
-            (packages."x86_64-linux"."base" { inherit mcu chip_select f_cpu; })
-          ];
-
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
-          INCLUDE_DIRS = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-
-          buildPhase = ''
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o rng.o -c ${src}/rng/rng.c
-            '';
-
-          installPhase = ''
-            mkdir $out
-            cp rng/rng.h rng.o $out/
-            '';
         };
 
       packages."x86_64-linux"."animation" =
-        { gcc, mcu, chip_select, f_cpu }:
+        { gcc, cflags }:
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
-        in pkgs.stdenv.mkDerivation rec {
+        in mkLibrary {
-          name = "animation";
+          pkgs = pkgs;
-          src = ./.;
+          gcc = gcc;
-
+          cflags = cflags;
-          # CFLAGS = cflags { inherit mcu chip_select f_cpu; };
+          pname = "animation";
-
+          psrc = ./animation;
-          buildPhase = ''
-            ${gcc} -o animation.o -c ${src}/animation/animation.c
-            '';
-
-          installPhase = ''
-            mkdir $out
-            cp animation/animation.h animation.o $out/
-            '';
-        };
-
-      packages."x86_64-linux"."animation-test" =
-        let
-          pkgs = import nixpkgs { system = "x86_64-linux"; };
-          lib = pkgs.lib;
-        in pkgs.stdenv.mkDerivation rec {
-          name = "animation-test";
-          src = ./.;
-
-          buildInputs = [
-            (packages."x86_64-linux"."animation" { inherit gcc; })
-          ];
-
-          INCLUDE_DIRS = lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-          gcc = "${pkgs.gcc}/bin/gcc";
-
-          buildPhase = ''
-            ${gcc} ${INCLUDE_DIRS} -o main.o -c ${src}/animation/main.c
-            ${gcc} ${INCLUDE_DIRS} -o animation-test main.o ${OBJECT_FILES}
-            '';
-          installPhase = ''
-            mkdir $out
-            cp animation-test $out
-            '';
         };
 
       packages."x86_64-linux"."sk9822" =
-        { mcu, chip_select, f_cpu }:
+        { gcc, cflags }:
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
-          avr = pkgs.pkgsCross.avr.buildPackages;
+        in mkLibrary {
-        in pkgs.stdenv.mkDerivation rec {
+          pkgs = pkgs;
-          name = "sk9822";
+          gcc = gcc;
-          src = ./.;
+          cflags = cflags;
-
+          pname = "sk9822";
-          buildInputs = [
+          psrc = ./sk9822;
-            (packages."x86_64-linux"."base" { inherit mcu chip_select f_cpu; })
+          pbuildInputs = [
+            (packages."x86_64-linux"."dio" { inherit gcc cflags; })
           ];
-
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
-          INCLUDE_DIRS = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-
-          buildPhase = ''
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o sk9822.o -c ${src}/sk9822/sk9822.c
-            '';
-          installPhase = ''
-            mkdir $out
-            cp sk9822/sk9822.h sk9822.o $out/
-            '';
         };
 
       packages."x86_64-linux"."shift-register" =
-        { mcu, chip_select, f_cpu }:
+        { gcc, cflags }:
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
-          avr = pkgs.pkgsCross.avr.buildPackages;
+        in mkLibrary {
-        in pkgs.stdenv.mkDerivation rec {
+          pkgs = pkgs;
-          name = "shift-register";
+          gcc = gcc;
-          src = ./.;
+          cflags = cflags;
-
+          pname = "shift-register";
-          buildInputs = [
+          psrc = ./shift-register;
-            (packages."x86_64-linux"."base" { inherit mcu chip_select f_cpu; })
+          pbuildInputs = [
+            (packages."x86_64-linux"."dio" { inherit gcc cflags; })
           ];
-
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
-          INCLUDE_DIRS = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-
-          buildPhase = ''
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o shift_register.o -c ${src}/shift_register/shift_register.c
-            '';
-          installPhase = ''
-            mkdir $out
-            cp shift_register/shift_register.h shift_register.o $out/
-            '';
         };
 
       packages."x86_64-linux"."spi" =
-        { mcu, chip_select, f_cpu }:
+        { gcc, cflags }:
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
-          avr = pkgs.pkgsCross.avr.buildPackages;
+        in mkLibrary {
-        in pkgs.stdenv.mkDerivation rec {
+          pkgs = pkgs;
-          name = "spi";
+          gcc = gcc;
-          src = ./.;
+          cflags = cflags;
-
+          pname = "spi";
-          buildInputs = [
+          psrc = ./spi;
-            (packages."x86_64-linux"."base" { inherit mcu chip_select f_cpu; })
+          pbuildInputs = [
+            (packages."x86_64-linux"."dio" { inherit gcc cflags; })
           ];
-
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
-          INCLUDE_DIRS = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-
-          buildPhase = ''
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o spi.o -c ${src}/spi/spi.c
-            '';
-          installPhase = ''
-            mkdir $out
-            cp spi/spi.h spi.o $out/
-            '';
         };
 
       packages."x86_64-linux"."rfm" =
-        { mcu, chip_select, f_cpu }:
+        { gcc, cflags }:
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
-          avr = pkgs.pkgsCross.avr.buildPackages;
+        in mkLibrary {
-        in pkgs.stdenv.mkDerivation rec {
+          pkgs = pkgs;
-          name = "rfm";
+          gcc = gcc;
-          src = ./.;
+          cflags = cflags;
-
+          pname = "rfm";
-          buildInputs = [
+          psrc = ./rfm69hcw;
-            (packages."x86_64-linux"."base" { inherit mcu chip_select f_cpu; })
+          pbuildInputs = [
-            (packages."x86_64-linux"."spi" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."dio" { inherit gcc cflags; })
+            (packages."x86_64-linux"."spi" { inherit gcc cflags; })
           ];
-
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
-          INCLUDE_DIRS = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-
-          buildPhase = ''
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o rfm.o -c ${src}/rfm69hcw/rfm.c
-            '';
-          installPhase = ''
-            mkdir $out
-            cp rfm69hcw/rfm.h rfm.o $out/
-            '';
         };
 
       packages."x86_64-linux"."display" =
-        { mcu, chip_select, f_cpu }:
+        { gcc, cflags }:
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
-          avr = pkgs.pkgsCross.avr.buildPackages;
+        in mkLibrary {
-        in pkgs.stdenv.mkDerivation rec {
+          pkgs = pkgs;
-          name = "display";
+          gcc = gcc;
-          src = ./.;
+          cflags = cflags;
-
+          pname = "display";
-          buildInputs = [
+          psrc = ./display;
-            (packages."x86_64-linux"."base" { inherit mcu chip_select f_cpu; })
+          pbuildInputs = [
-            (packages."x86_64-linux"."shift-register" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."dio" { inherit gcc cflags; })
+            (packages."x86_64-linux"."shift-register" { inherit gcc cflags; })
           ];
-
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
-          INCLUDE_DIRS = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-
-          buildPhase = ''
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o display.o -c ${src}/display/display.c
-            '';
-          installPhase = ''
-            mkdir $out
-            cp display/display.h display.o $out/
-            '';
-        };
-
-      packages."x86_64-linux"."flame" =
-        { mcu, chip_select, f_cpu }:
-        let
-          pkgs = import nixpkgs { system = "x86_64-linux"; };
-          lib = pkgs.lib;
-          avr = pkgs.pkgsCross.avr.buildPackages;
-        in pkgs.stdenv.mkDerivation rec {
-          name = "flame";
-          src = ./.;
-
-          buildInputs = [
-            (packages."x86_64-linux"."base" { inherit mcu chip_select f_cpu; })
-            (packages."x86_64-linux"."sk9822" { inherit mcu chip_select f_cpu; })
-            (packages."x86_64-linux"."rng" { inherit mcu chip_select f_cpu; })
-            (packages."x86_64-linux"."animation" { inherit mcu chip_select f_cpu;
-                                                   gcc = "${avr.gcc}/bin/avr-gcc"; })
-          ];
-
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
-          INCLUDE_DIRS = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-
-          buildPhase = ''
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o main.o -c ${src}/flame/main.c
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o flame.elf main.o ${OBJECT_FILES}
-            $OBJCOPY -O ihex flame.elf flame.hex
-            '';
-          installPhase = ''
-            mkdir $out
-            cp flame.elf flame.hex $out
-            '';
         };
 
       packages."x86_64-linux"."prime-tx" =
-        { mcu, chip_select, f_cpu }:
+        { gcc, cflags }:
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
-          lib = pkgs.lib;
+        in mkProgram {
-          avr = pkgs.pkgsCross.avr.buildPackages;
+          pkgs = pkgs;
-        in pkgs.stdenv.mkDerivation rec {
+          gcc = gcc;
-          name = "prime-tx";
+          cflags = cflags;
-          src = ./.;
+          pname = "prime-tx";
-
+          psrc = ./prime-tx;
-          buildInputs = [
+          pbuildInputs = [
-            (packages."x86_64-linux"."base" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."dio" { inherit gcc cflags; })
-            (packages."x86_64-linux"."spi" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."spi" { inherit gcc cflags; })
-            (packages."x86_64-linux"."shift-register" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."shift-register" { inherit gcc cflags; })
-            (packages."x86_64-linux"."rfm" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."rfm" { inherit gcc cflags; })
-            (packages."x86_64-linux"."display" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."display" { inherit gcc cflags; })
           ];
-
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
-          INCLUDE_DIRS = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-
-
-          buildPhase = ''
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o main.o -c ${src}/prime-tx/main.c
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} -o prime-tx.elf main.o ${OBJECT_FILES}
-            $OBJCOPY -O ihex prime-tx.elf prime-tx.hex
-            '';
-
-          installPhase = ''
-            mkdir $out
-            cp prime-tx.elf prime-tx.hex $out
-            '';
         };
 
       packages."x86_64-linux"."radio-rx" =
-        { mcu, chip_select, f_cpu }:
+        { gcc, cflags }:
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
-          lib = pkgs.lib;
+        in mkProgram {
-          avr = pkgs.pkgsCross.avr.buildPackages;
+          pkgs = pkgs;
-        in pkgs.stdenv.mkDerivation rec {
+          gcc = gcc;
-          name = "radio-rx";
+          cflags = cflags;
-          src = ./.;
+          pname = "radio-rx";
-
+          psrc = ./radio-rx;
-          buildInputs = [
+          pbuildInputs = [
-            (packages."x86_64-linux"."base" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."dio" { inherit gcc cflags; })
-            (packages."x86_64-linux"."spi" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."spi" { inherit gcc cflags; })
-            (packages."x86_64-linux"."shift-register" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."shift-register" { inherit gcc cflags; })
-            (packages."x86_64-linux"."rfm" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."rfm" { inherit gcc cflags; })
-            (packages."x86_64-linux"."display" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."display" { inherit gcc cflags; })
           ];
-
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
-          INCLUDE_DIRS = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-
-          buildPhase = ''
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o main.o -c ${src}/radio-rx/main.c
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} -o radio-rx.elf main.o ${OBJECT_FILES}
-            $OBJCOPY -O ihex radio-rx.elf radio-rx.hex
-            '';
-          installPhase = ''
-            mkdir $out
-            cp radio-rx.elf radio-rx.hex $out
-            '';
         };
 
-      packages."x86_64-linux"."interrupts-standalone" = (packages."x86_64-linux"."interrupts" atmega32u4);
+      packages."x86_64-linux"."lantern_" = 
-
+      let
-      packages."x86_64-linux"."interrupts" =
+        pkgs = import nixpkgs { system = "x86_64-linux"; };
-        { mcu, chip_select, f_cpu }:
+        avr = pkgs.pkgsCross.avr.buildPackages;
+      in packages."x86_64-linux"."lantern" { gcc = "${avr.gcc}/bin/avr-gcc"; cflags = mcu_cflags atmega32u4; };
+      packages."x86_64-linux"."lantern" =
+        { gcc, cflags, avr }:
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
-          lib = pkgs.lib;
+        in mkProgram {
-          avr = pkgs.pkgsCross.avr.buildPackages;
+          pkgs = pkgs;
-        in pkgs.stdenv.mkDerivation rec {
+          gcc = gcc;
-          name = "interrupts";
+          cflags = cflags;
-          src = ./.;
+          pname = "lantern";
+          psrc = ./lantern;
+          inherit avr;
 
-          buildInputs = [
+          pbuildInputs = [
-            (packages."x86_64-linux"."base" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."animation" { inherit gcc cflags; })
-            (packages."x86_64-linux"."shift-register" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."dio" { inherit gcc cflags; })
-            (packages."x86_64-linux"."display" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."display" { inherit gcc cflags; })
+            (packages."x86_64-linux"."rfm" { inherit gcc cflags; })
+            (packages."x86_64-linux"."shift-register" { inherit gcc cflags; })
+            (packages."x86_64-linux"."sk9822" { inherit gcc cflags; })
+            (packages."x86_64-linux"."spi" { inherit gcc cflags; })
           ];
-
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
-          INCLUDE_DIRS = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-
-          buildPhase = ''
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o main.o -c ${src}/interrupts/main.c
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} -o interrupts.elf main.o ${OBJECT_FILES}
-            $OBJCOPY -O ihex interrupts.elf interrupts.hex
-            '';
-          installPhase = ''
-            mkdir $out
-            cp interrupts.elf interrupts.hex $out
-            '';
         };
 
-      packages."x86_64-linux"."power-management-standalone" = (packages."x86_64-linux"."power-management" attiny85);
+      packages."x86_64-linux"."lantern-controller_" = 
-
+      let
-      packages."x86_64-linux"."power-management" =
+        pkgs = import nixpkgs { system = "x86_64-linux"; };
-        { mcu, chip_select, f_cpu }:
+        avr = pkgs.pkgsCross.avr.buildPackages;
+      in packages."x86_64-linux"."lantern-controller" { gcc = "${avr.gcc}/bin/avr-gcc"; cflags = mcu_cflags atmega32u4; avr = true; };
+      packages."x86_64-linux"."lantern-controller" =
+        { gcc, cflags, avr }:
         let
           pkgs = import nixpkgs { system = "x86_64-linux"; };
-          lib = pkgs.lib;
+        in mkProgram {
-          avr = pkgs.pkgsCross.avr.buildPackages;
+          pkgs = pkgs;
-        in pkgs.stdenv.mkDerivation rec {
+          gcc = gcc;
-          name = "power-management";
+          cflags = cflags;
-          src = ./.;
+          pname = "lantern-controller";
+          psrc = ./lantern-controller;
+          inherit avr;
 
-          buildInputs = [
+          pbuildInputs = [
-            (packages."x86_64-linux"."base" { inherit mcu chip_select f_cpu; })
+            (packages."x86_64-linux"."dio" { inherit gcc cflags; })
+            (packages."x86_64-linux"."spi" { inherit gcc cflags; })
+            (packages."x86_64-linux"."rfm" { inherit gcc cflags; })
           ];
-
-          CFLAGS = cflags { inherit mcu chip_select f_cpu; };
-          INCLUDE_DIRS = pkgs.lib.concatStringsSep " " (map (dir: "-I${dir}") buildInputs);
-          OBJECT_FILES = pkgs.lib.concatStringsSep " " (map (dir: "${dir}/*.o") buildInputs);
-
-          buildPhase = ''
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} ${INCLUDE_DIRS} -o main.o -c ${src}/power-management/main.c
-            ${avr.gcc}/bin/avr-gcc ${CFLAGS} -o power-management.elf main.o ${OBJECT_FILES}
-            $OBJCOPY -O ihex power-management.elf power-management.hex
-            '';
-          installPhase = ''
-            mkdir $out
-            cp power-management.elf power-management.hex $out
-            '';
         };
 
       devShell."x86_64-linux" =

flame/main.c

@@ -1,7 +1,7 @@
 #include <avr/io.h>
 #include <util/delay.h>
 
-#include <base.h>
+#include <dio.h>
 #include <sk9822.h>
 #include <rng.h>
 #include <animation.h>
@@ -88,14 +88,16 @@ int main (void) {
     PORTB = 0;
     _delay_ms(50);
 
-    dio_t data_pin = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 0 };
+    sk9822_t lights = {
-    dio_t clock_pin = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 2 };
+        .data_pin = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 0 },
+        .clock_pin = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 2 }
+    };
 
     rng_t rng = rng_new(0);
     animation_t animation = animation_new();
     while (1) {
         animation_step(&animation, &rng);
-        send_pixels(data_pin, clock_pin, &animation.lamp, 1);
+        sk9822_send(&lights, &animation.lamp, 1);
         _delay_ms(FRAME_DELAY_MS);
     }
 }

interrupts/main.c

@@ -1,4 +1,4 @@
-#include <base.h>
+#include <dio.h>
 #include <display.h>
 #include <stdbool.h>
 #include <stdio.h>

lantern-controller/main.c

@@ -0,0 +1,90 @@
+#include <avr/interrupt.h>
+#include <avr/sleep.h>
+#include <dio.h>
+#include <rfm.h>
+#include <stdbool.h>
+#include <string.h>
+
+typedef enum {
+    lme_off,
+    lme_normal,
+    lme_spooky,
+    lme_eerie,
+} lantern_msg_e;
+
+dio_t buttons[4] = {
+    { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 5 },
+    { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 6 },
+    { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 7 },
+    { .ddr = &DDRD, .port = &PORTD, .pin = &PIND, .addr = 6 },
+};
+
+typedef struct {
+    bool button_press[4];
+} status_flags_t;
+
+status_flags_t status_flags = {
+    .button_press = { false, false, false, false }
+};
+
+ISR(INT2_vect) {
+    for (int i = 0; i < 4; i++) {
+        status_flags.button_press[i] = dio_read(&buttons[i]);
+    }
+}
+
+int main(void) {
+    EIMSK = 1 << INT2;
+    EICRA |= 1 << ISC21 | 1 << ISC20;
+
+    dio_t int2 = { .ddr = &DDRD, .port = &PORTD, .pin = &PIND, .addr = 2 };
+    dio_set_direction(&int2, LINE_IN);
+    dio_set(&int2, false);
+
+    rfm_t radio = (rfm_t){
+        .spi    = {
+            .clock          = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 1 },
+            .data_out       = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 2 },
+            .data_in        = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 3 },
+            .chip_select    = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 4 },
+        },
+        .irq    = { .ddr = &DDRE, .port = &PORTE, .pin = &PINE, .addr = 6 },
+        .reset  = { .ddr = &DDRD, .port = &PORTD, .pin = &PIND, .addr = 4 },
+    };
+
+    rfm_error_e error;
+    rfm_init(&radio, (uint8_t [4]){ 0xde, 0xca, 0xfb, 0xad }, 4, &error);
+
+    set_sleep_mode(SLEEP_MODE_IDLE);
+    while(1) {
+        sei();
+        sleep_mode();
+        cli();
+
+        uint8_t msg;
+        if (status_flags.button_press[0]) {
+            status_flags.button_press[0] = false;
+            msg = lme_normal;
+        } else if (status_flags.button_press[1]) {
+            status_flags.button_press[1] = false;
+            msg = lme_spooky;
+        } else if (status_flags.button_press[2]) {
+            status_flags.button_press[2] = false;
+            msg = lme_eerie;
+        } else if (status_flags.button_press[3]) {
+            status_flags.button_press[3] = false;
+            msg = lme_off;
+        } else {
+            continue;
+        }
+
+        rfm_transmit(&radio, &msg, 1);
+
+        interrupt_flags_t flags = rfm_interrupts(&radio);
+        while(!flags.packet_sent) {
+            _delay_ms(1);
+            flags = rfm_interrupts(&radio);
+        }
+        rfm_standby(&radio);
+    }
+}

lantern/lantern.c

@@ -0,0 +1,349 @@
+/*
+Copyright 2022, Savanni D'Gerinel <savanni@luminescent-dreams.com>
+
+This file is part of Savanni's AVR library.
+
+This AVR library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+
+This AVR library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with this AVR library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "lantern.h"
+
+uint8_t bound_uint8(int value, uint8_t min, uint8_t max) {
+    if (value > max) {
+        return max;
+    } else if (value < min) {
+        return min;
+    } else {
+        return value;
+    }
+}
+
+uint8_t random_step(uint8_t value, uint8_t min, uint8_t max) {
+    int8_t step = (rand() % 40) - 20;
+    int new_value = value + step;
+
+    return bound_uint8(new_value, min, max);
+}
+
+animation_t animation_new(void) {
+    return (animation_t) {
+        .color = { .brightness = 16, .r = 0, .g = 0, .b = 0 },
+        .red_line = time_line_new(0, 0, 0, 0),
+        .green_line = time_line_new(0, 0, 0, 0),
+        .blue_line = time_line_new(0, 0, 0, 0),
+
+        .frame = 0,
+        .duration = 0,
+    };
+}
+
+void animation_begin(animation_t *self, uint8_t rdest, uint8_t gdest, uint8_t bdest, uint8_t duration) {
+    self->red_line = time_line_new(0, self->color.r, duration, rdest);
+    self->green_line = time_line_new(0, self->color.g, duration, gdest);
+    self->blue_line = time_line_new(0, self->color.b, duration, bdest);
+    self->frame = 0;
+    self->duration = duration;
+}
+
+void animation_step(animation_t *self) {
+    if (self->frame == self->duration) {
+        self->frame = 0;
+        self->duration = 0;
+    } else {
+        self->frame++;
+        self->color.r = bound_uint8(time_line_next(&self->red_line), 0, 255);
+        self->color.g = bound_uint8(time_line_next(&self->green_line), 0, 255);
+        self->color.b = bound_uint8(time_line_next(&self->blue_line), 0, 255);
+    }
+}
+
+bool animation_running(animation_t *self) {
+    return self->frame != self->duration;
+}
+
+lantern_t lantern_new(sk9822_t lights) {
+    sk9822_init(&lights);
+    return (lantern_t){
+        .lights = lights,
+        .color_scheme = cse_off,
+        .animations = {
+            animation_new(),
+            animation_new(),
+            animation_new(),
+            animation_new(),
+            animation_new(),
+            animation_new(),
+            animation_new(),
+            animation_new(),
+            animation_new(),
+        }
+    };
+}
+
+void lantern_start_off(lantern_t *self, int light_idx) {
+    animation_begin(
+            &self->animations[light_idx],
+            0,
+            0,
+            0,
+            1);
+}
+
+void lantern_start_normal(lantern_t *self, int light_idx) {
+    switch (light_idx) {
+        case 0:
+            animation_begin(
+                    &self->animations[0],
+                    random_step(self->animations[0].color.r, 180, 255),
+                    random_step(self->animations[0].color.g, 20, 50),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[3],
+                    random_step(self->animations[3].color.r, 180, 255),
+                    random_step(self->animations[3].color.g, 20, 50),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[6],
+                    random_step(self->animations[3].color.r, 180, 255),
+                    random_step(self->animations[3].color.g, 20, 50),
+                    0,
+                    5);
+            break;
+        case 1:
+            animation_begin(
+                    &self->animations[1],
+                    random_step(self->animations[1].color.r, 160, 230),
+                    random_step(self->animations[1].color.g, 10, 30),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[4],
+                    random_step(self->animations[4].color.r, 160, 230),
+                    random_step(self->animations[4].color.g, 10, 30),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[7],
+                    random_step(self->animations[7].color.r, 160, 230),
+                    random_step(self->animations[7].color.g, 10, 30),
+                    0,
+                    5);
+            break;
+        case 2:
+            animation_begin(
+                    &self->animations[2],
+                    random_step(self->animations[2].color.r, 140, 170),
+                    random_step(self->animations[2].color.g, 0, 10),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[5],
+                    random_step(self->animations[5].color.r, 140, 170),
+                    random_step(self->animations[5].color.g, 0, 10),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[8],
+                    random_step(self->animations[8].color.r, 140, 170),
+                    random_step(self->animations[8].color.g, 0, 10),
+                    0,
+                    5);
+            break;
+    }
+}
+
+void lantern_start_spooky(lantern_t *self, int light_idx) {
+    switch (light_idx) {
+        case 0:
+            animation_begin(
+                    &self->animations[0],
+                    0,
+                    random_step(self->animations[0].color.g, 40, 140),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[3],
+                    0,
+                    random_step(self->animations[3].color.g, 40, 140),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[6],
+                    0,
+                    random_step(self->animations[6].color.g, 40, 140),
+                    0,
+                    5);
+            break;
+        case 1:
+            animation_begin(
+                    &self->animations[1],
+                    0,
+                    random_step(self->animations[1].color.g, 20, 80),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[4],
+                    0,
+                    random_step(self->animations[4].color.g, 20, 80),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[7],
+                    0,
+                    random_step(self->animations[7].color.g, 20, 80),
+                    0,
+                    5);
+            break;
+        case 2:
+            animation_begin(
+                    &self->animations[2],
+                    0,
+                    random_step(self->animations[2].color.g, 10, 40),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[5],
+                    0,
+                    random_step(self->animations[5].color.g, 10, 40),
+                    0,
+                    5);
+            animation_begin(
+                    &self->animations[8],
+                    0,
+                    random_step(self->animations[8].color.g, 10, 40),
+                    0,
+                    5);
+            break;
+    }
+}
+
+void lantern_start_eerie(lantern_t *self, int light_idx) {
+    switch (light_idx) {
+        case 0:
+            animation_begin(
+                    &self->animations[0],
+                    random_step(self->animations[0].color.r, 20, 40),
+                    random_step(self->animations[0].color.g, 20, 40),
+                    random_step(self->animations[0].color.b, 80, 120),
+                    5);
+            animation_begin(
+                    &self->animations[3],
+                    random_step(self->animations[3].color.r, 20, 40),
+                    random_step(self->animations[3].color.g, 20, 40),
+                    random_step(self->animations[3].color.b, 80, 120),
+                    5);
+            animation_begin(
+                    &self->animations[6],
+                    random_step(self->animations[6].color.r, 20, 40),
+                    random_step(self->animations[6].color.g, 20, 40),
+                    random_step(self->animations[6].color.b, 80, 120),
+                    5);
+            break;
+        case 1:
+            animation_begin(
+                    &self->animations[1],
+                    random_step(self->animations[1].color.r, 0, 30),
+                    random_step(self->animations[1].color.g, 0, 30),
+                    random_step(self->animations[1].color.b, 60, 100),
+                    5);
+            animation_begin(
+                    &self->animations[4],
+                    random_step(self->animations[4].color.r, 0, 30),
+                    random_step(self->animations[4].color.g, 0, 30),
+                    random_step(self->animations[4].color.b, 60, 100),
+                    5);
+            animation_begin(
+                    &self->animations[7],
+                    random_step(self->animations[7].color.r, 0, 30),
+                    random_step(self->animations[7].color.g, 0, 30),
+                    random_step(self->animations[7].color.b, 60, 100),
+                    5);
+            break;
+        case 2:
+            animation_begin(
+                    &self->animations[2],
+                    random_step(self->animations[2].color.r, 0, 10),
+                    random_step(self->animations[2].color.g, 0, 10),
+                    random_step(self->animations[2].color.b, 20, 40),
+                    5);
+            animation_begin(
+                    &self->animations[5],
+                    random_step(self->animations[5].color.r, 0, 10),
+                    random_step(self->animations[5].color.g, 0, 10),
+                    random_step(self->animations[5].color.b, 20, 40),
+                    5);
+            animation_begin(
+                    &self->animations[8],
+                    random_step(self->animations[8].color.r, 0, 10),
+                    random_step(self->animations[8].color.g, 0, 10),
+                    random_step(self->animations[8].color.b, 20, 40),
+                    5);
+            break;
+    }
+}
+
+void lantern_set_mode(lantern_t *self, color_scheme_e scheme) {
+    self->color_scheme = scheme;
+}
+
+void lantern_step(lantern_t *self, rgb_t colors[LIGHT_COUNT]) {
+    for (int i = 0; i < LIGHT_COUNT; i++) {
+        if (!animation_running(&self->animations[i])) {
+            switch (self->color_scheme) {
+                case cse_off:
+                    lantern_start_off(self, i);
+                    break;
+                case cse_normal:
+                    lantern_start_normal(self, i);
+                    break;
+                case cse_spooky:
+                    lantern_start_spooky(self, i);
+                    break;
+                case cse_eerie:
+                    lantern_start_eerie(self, i);
+                    break;
+                case cse_flash:
+                    break;
+            }
+        }
+
+        animation_step(&self->animations[i]);
+        colors[i] = self->animations[i].color;
+    }
+}
+
+/*
+void lantern_show(lantern_t *lantern, display_t *display) {
+    char msg1[20];
+    char msg2[20];
+
+    snprintf(msg1, 20, "[%d,%d] %x,%x,%x",
+            lantern->animations[0].frame,
+            lantern->animations[0].duration,
+            lantern->animations[0].color.r,
+            lantern->animations[0].color.g,
+            lantern->animations[0].color.b
+    );
+    snprintf(msg2, 20, "%x,%x,%x %x,%x,%x",
+            lantern->animations[1].color.r,
+            lantern->animations[1].color.g,
+            lantern->animations[1].color.b,
+            lantern->animations[2].color.r,
+            lantern->animations[2].color.g,
+            lantern->animations[2].color.b
+    );
+    display_clear(display);
+    display_write_message(display, msg1);
+    display_set_location(display, 1, 0);
+    display_write_message(display, msg2);
+}
+*/
+

lantern/lantern.h

@@ -0,0 +1,55 @@
+/*
+Copyright 2022, Savanni D'Gerinel <savanni@luminescent-dreams.com>
+
+This file is part of Savanni's AVR library.
+
+This AVR library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+
+This AVR library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with this AVR library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <animation.h>
+#include <display.h>
+#include <sk9822.h>
+
+#ifndef __LANTERN_H__
+#define __LANTERN_H__
+
+#define LIGHT_COUNT         9
+
+typedef struct {
+    rgb_t color;
+
+    time_line_t red_line;
+    time_line_t green_line;
+    time_line_t blue_line;
+
+    uint8_t frame;
+    uint8_t duration;
+} animation_t;
+
+typedef enum {
+    cse_off,
+    cse_normal,
+    cse_spooky,
+    cse_eerie,
+    cse_flash
+} color_scheme_e;
+
+typedef struct {
+    sk9822_t lights;
+
+    color_scheme_e color_scheme;
+    animation_t animations[LIGHT_COUNT];
+} lantern_t;
+
+lantern_t lantern_new(sk9822_t);
+void lantern_set_mode(lantern_t *, color_scheme_e);
+void lantern_step(lantern_t *, rgb_t *);
+
+void lantern_show(lantern_t *, display_t *);
+
+#endif
+

lantern/main.c

@@ -0,0 +1,212 @@
+/*
+Copyright 2022, Savanni D'Gerinel <savanni@luminescent-dreams.com>
+
+This file is part of Savanni's AVR library.
+
+This AVR library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+
+This AVR library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with this AVR library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <avr/interrupt.h>
+#include <avr/sleep.h>
+#include <dio.h>
+#include <display.h>
+#include "lantern.h"
+#include <rfm.h>
+#include <sk9822.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define FPS                 15
+#define TICKS_PER_SECOND    7812
+#define FPS_TIMEOUT         TICKS_PER_SECOND / FPS
+#define FPS_MS              1000 / FPS
+#define PULSE_OFF_COUNT     FPS * 5
+#define PULSE_ON_COUNT      5
+
+typedef enum {
+    lme_off,
+    lme_normal,
+    lme_spooky,
+    lme_eerie,
+} lantern_msg_e;
+
+typedef struct {
+    bool frame_timeout;
+} status_flags_t;
+
+status_flags_t status_flags;
+
+/*
+ISR(TIMER1_COMPA_vect) {
+    status_flags.frame_timeout = true;
+}
+*/
+
+ISR(INT6_vect) {
+}
+
+/*
+void setup_fps_timer(void) {
+    // WGM = 0100: CTC with OCR1nA top
+    // CS = 101: clock / 1024
+    TCCR1A = 0;
+    TCCR1B = _BV(3) | _BV(2) | _BV(0);
+
+    // Set the top for the counter
+    OCR1AH = FPS_TIMEOUT >> 8;
+    OCR1AL = FPS_TIMEOUT & 0xff;
+
+    // Enable compare on A match interrupt
+    TIMSK1 |= _BV(1);
+}
+*/
+
+void startup_animation(sk9822_t *lights, rgb_t *colors) {
+    for (int i = 0; i < LIGHT_COUNT; i++) {
+        colors[i].brightness = 1;
+    }
+
+    for (int i = 0; i < LIGHT_COUNT; i++) {
+        colors[i].b = 0;
+        colors[i].r = 128;
+        sk9822_send(lights, colors, LIGHT_COUNT);
+        _delay_ms(50);
+    }
+
+    for (int i = 0; i < LIGHT_COUNT; i++) {
+        colors[i].r = 0;
+        colors[i].g = 128;
+        sk9822_send(lights, colors, LIGHT_COUNT);
+        _delay_ms(100);
+    }
+
+    for (int i = 0; i < LIGHT_COUNT; i++) {
+        colors[i].g = 0;
+        colors[i].b = 128;
+        sk9822_send(lights, colors, LIGHT_COUNT);
+        _delay_ms(100);
+    }
+}
+
+int main(void) {
+    EIMSK = 1 << INT6 | 1 << INT2;
+    EICRA |= 1 << ISC21 | 1 << ISC20;
+    EICRB |= 1 << ISC61 | 1 << ISC60;
+
+    status_flags.frame_timeout = false;
+
+    // Disable unneeded modules
+    PRR0 = _BV(7) | _BV(5) | _BV(2);
+    PRR1 = _BV(7) | _BV(4) | _BV(3) | _BV(0);
+
+    rfm_t radio = (rfm_t){
+        .spi    = {
+            .clock          = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 1 },
+            .data_out       = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 2 },
+            .data_in        = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 3 },
+            .chip_select    = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 4 },
+        },
+        .irq    = { .ddr = &DDRE, .port = &PORTE, .pin = &PINE, .addr = 6 },
+        .reset  = { .ddr = &DDRD, .port = &PORTD, .pin = &PIND, .addr = 4 },
+    };
+
+    rfm_error_e error;
+    rfm_init(&radio, (uint8_t [4]){ 0xde, 0xca, 0xfb, 0xad }, 4, &error);
+    rfm_listen(&radio);
+
+    sk9822_t lights = {
+        .clock_pin = { .ddr = &DDRC, .port = &PORTC, .pin = &PINC, .addr = 7 },
+        .data_pin = { .ddr = &DDRD, .port = &PORTD, .pin = &PIND, .addr = 6 }
+    };
+
+    rgb_t error_indicator[LIGHT_COUNT] = {
+        { .brightness = 1, .r = 255, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 1, .r = 255, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 1, .r = 255, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+    };
+
+    lantern_t lantern = lantern_new(lights);
+    lantern_set_mode(&lantern, cse_off);
+
+    // setup_fps_timer();
+
+    // set_sleep_mode(SLEEP_MODE_IDLE);
+
+    rgb_t colors[LIGHT_COUNT] = {
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+        { .brightness = 0, .r = 0, .g = 0, .b = 0 },
+    };
+    _delay_ms(1000);
+    startup_animation(&lights, (rgb_t *)&colors);
+
+    while(1) {
+        /*
+        if (status_flags.frame_timeout) {
+            status_flags.frame_timeout = false;
+            lantern_step(&lantern, colors);
+            sk9822_send(&lights, colors, LIGHT_COUNT);
+        }
+        */
+
+        lantern_step(&lantern, colors);
+        sk9822_send(&lights, colors, LIGHT_COUNT);
+
+        interrupt_flags_t flags = rfm_interrupts(&radio);
+        while (flags.fifo_not_empty) {
+            uint8_t msg[60];
+            uint8_t length;
+
+            rfm_receive(&radio, (uint8_t *)msg, &length);
+            if (length == 1) {
+                switch (msg[0]) {
+                    case lme_off:
+                        lantern_set_mode(&lantern, cse_off);
+                        break;
+                    case lme_normal:
+                        lantern_set_mode(&lantern, cse_normal);
+                        break;
+                    case lme_spooky:
+                        lantern_set_mode(&lantern, cse_spooky);
+                        break;
+                    case lme_eerie:
+                        lantern_set_mode(&lantern, cse_eerie);
+                        break;
+                    default:
+                        break;
+                }
+            }
+            flags = rfm_interrupts(&radio);
+        }
+
+        _delay_ms(FPS_MS);
+        /*
+        sei();
+        sleep_mode();
+        cli();
+        */
+    }
+
+    sk9822_send(&lights, error_indicator, LIGHT_COUNT);
+    _delay_ms(1000);
+
+    return 0;
+}

morse/morse.c

@@ -72,29 +72,29 @@ const struct morse_codepoint * morse_lookup(char val) {
     return &MORSE[idx];
 }
 
-void send_codepoint(gpio_t *gpio, const struct morse_codepoint *codepoint) {
+void send_codepoint(dio_t *dio, const struct morse_codepoint *codepoint) {
-    const uint8_t one = 1 << gpio->addr;
+    const uint8_t one = 1 << dio->addr;
     for (size_t i = 0; i < codepoint->length; i++) {
-        *gpio->port = *(gpio->port) | one;
+        *dio->port = *(dio->port) | one;
         if (codepoint->values[i] == DOT) {
             _delay_ms(DOT * SCALE);
         } else {
             _delay_ms(DASH * SCALE);
         }
-        *gpio->port = *(gpio->port) & ~one;
+        *dio->port = *(dio->port) & ~one;
         _delay_ms(DIVIDER * SCALE);
     }
     _delay_ms(INTERCHAR * SCALE);
 }
 
-void send_morse(gpio_t *gpio, char *message) {
+void send_morse(dio_t *dio, char *message) {
     for (size_t i = 0; i < strlen(message); i++) {
         if (message[i] == ' ') {
             _delay_ms(INTERWORD * SCALE);
         }
         const struct morse_codepoint *codepoint = morse_lookup(message[i]);
         if (codepoint != NULL) {
-            send_codepoint(gpio, codepoint);
+            send_codepoint(dio, codepoint);
         }
     }
 }

morse/morse.h

@@ -16,7 +16,7 @@ You should have received a copy of the GNU General Public License along with Lum
 
 #include <stdint.h>
 #include <stdlib.h>
-#include <base.h>
+#include <dio.h>
 
 /* TODO: make this parameterizable */
 #define DOT 1
@@ -26,6 +26,6 @@ You should have received a copy of the GNU General Public License along with Lum
 #define INTERWORD 4
 #define SCALE 100
 
-void send_morse(gpio_t *gpio, char *message);
+void send_morse(dio_t *dio, char *message);
 
 #endif

power-management/main.c

@@ -1,4 +1,4 @@
-#include <base.h>
+#include <dio.h>
 
 #define TIMEOUT 1
 

prime-tx/main.c

@@ -1,5 +1,5 @@
 #include <avr/io.h>
-#include <base.h>
+#include <dio.h>
 #include <display.h>
 #include <rfm.h>
 #include <spi.h>

radio-rx/main.c

@@ -1,5 +1,5 @@
 #include <avr/io.h>
-#include <base.h>
+#include <dio.h>
 #include <display.h>
 #include <rfm.h>
 #include <spi.h>
@@ -50,9 +50,9 @@ void status(display_t *display, rfm_t *radio, int clock) {
 int main(void) {
     display_t display = {
         .reg = {
-            .output         = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 7 },
+            .output         = { .ddr = &DDRF, .port = &PORTF, .pin = &PINF, .addr = 7 },
-            .shift_clock    = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 6 },
+            .shift_clock    = { .ddr = &DDRF, .port = &PORTF, .pin = &PINF, .addr = 6 },
-            .latch_clock    = { .ddr = &DDRB, .port = &PORTB, .pin = &PINB, .addr = 5 },
+            .latch_clock    = { .ddr = &DDRF, .port = &PORTF, .pin = &PINF, .addr = 5 },
         },
     };
 
@@ -132,8 +132,13 @@ int main(void) {
             char msg[16];
             snprintf(msg, 15, "[%d]: %d", length, packet[0]);
 
+            char msg_2[16];
+            snprintf(msg_2, 15, "RSSI: %d", rfm_rssi(&radio));
+
             display_clear(&display);
             display_write_message(&display, msg);
+            display_set_location(&display, 1, 0);
+            display_write_message(&display, msg_2);
             _delay_ms(1000);
         }
 

rfm69hcw/rfm.c

@@ -196,7 +196,7 @@ void rfm_transmit(rfm_t *rfm, uint8_t *data, uint8_t length) {
     rfm_set_mode(rfm, (op_mode_t){ .listen_on = false, .mode = standby });
     _rfm_set_low_power(rfm);
     _rfm_write(rfm, REG_FIFO, &length, 1);
-    _rfm_write(rfm, REG_FIFO, data, length);
+    _rfm_write(rfm, REG_FIFO, (uint8_t *)data, length);
     _rfm_write(rfm, REG_DIO_MAPPING1, (uint8_t [1]){ 0x00 }, 1);
     rfm_set_mode(rfm, (op_mode_t){ .listen_on = false, .mode = tx });
 }
@@ -206,13 +206,13 @@ void rfm_receive_mode(rfm_t *rfm) {
     rfm_set_mode(rfm, (op_mode_t){ .listen_on = false, .mode = rx });
 }
 
-void rfm_receive(rfm_t *rfm, uint8_t data[66], uint8_t *length) {
+void rfm_receive(rfm_t *rfm, uint8_t *data, uint8_t *length) {
     _rfm_write(rfm, REG_DIO_MAPPING1, (uint8_t [1]){ _BV(6) }, 1);
     rfm_set_mode(rfm, (op_mode_t){ .listen_on = false, .mode = rx });
     _rfm_read(rfm, REG_FIFO, length, 1);
 
     if (*length > 0) {
-        _rfm_read(rfm, 0x00, data, *length);
+        _rfm_read(rfm, 0x00, (uint8_t *)data, *length);
     }
 }
 
@@ -327,14 +327,16 @@ interrupt_flags_t rfm_interrupts(rfm_t *rfm) {
 }
 
 uint8_t rfm_rssi(rfm_t *rfm) {
-    uint8_t rssi_reg;
+    // uint8_t rssi_reg;
     uint8_t rssi_value;
 
+    /*
     _rfm_write(rfm, REG_RSSI_CONFIG, (uint8_t [1]){ _BV(0) }, 1);
 
     while(!(rssi_reg & _BV(1))) {
         _rfm_read(rfm, REG_RSSI_CONFIG, &rssi_reg, 1);
     }
+    */
 
     _rfm_read(rfm, REG_RSSI_VALUE, &rssi_value, 1);
 

rfm69hcw/rfm.h

@@ -13,7 +13,7 @@ You should have received a copy of the GNU General Public License along with Lum
 #ifndef __RFM_H__
 #define __RFM_H__
 
-#include <base.h>
+#include <dio.h>
 #include <spi.h>
 #include <stdbool.h>
 
@@ -76,7 +76,7 @@ void rfm_sleep(rfm_t *);
 void rfm_standby(rfm_t *);
 void rfm_receive_mode(rfm_t *);
 void rfm_transmit(rfm_t *rfm, uint8_t *data, uint8_t length);
-void rfm_receive(rfm_t *rfm, uint8_t data[66], uint8_t *length);
+void rfm_receive(rfm_t *rfm, uint8_t *data, uint8_t *length);
 
 op_mode_t rfm_mode(rfm_t *rfm);
 void rfm_set_mode(rfm_t *rfm, op_mode_t mode);

rng/rng.c

@@ -1,24 +0,0 @@
-/*
-Copyright 2022, Savanni D'Gerinel <savanni@luminescent-dreams.com>
-
-This file is part of Savanni's AVR library.
-
-Lumeto is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
-
-Lumeto is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License along with Lumeto. If not, see <https://www.gnu.org/licenses/>.
-*/
-
-#include "rng.h"
-
-rng_t rng_new(uint8_t seed) {
-    rng_t rng = { .mod = 255, .a = 253, .c = 41, .seed = seed };
-    return rng;
-}
-
-uint8_t rng_sample(rng_t *state) {
-    state->seed = (state->a * state->seed + state->c) % state->mod;
-    return state->seed;
-}
-

rng/rng.h

@@ -1,18 +0,0 @@
-#include <base.h>
-#include <stdlib.h>
-
-#ifndef __RNG_H__
-#define __RNG_H__
-
-typedef struct RNG {
-    uint8_t mod;
-    int8_t a;
-    int8_t c;
-    uint8_t seed;
-} rng_t;
-
-rng_t rng_new(uint8_t seed);
-
-uint8_t rng_sample(rng_t *state);
-
-#endif

shift-register/shift_register.c

@@ -11,7 +11,7 @@ You should have received a copy of the GNU General Public License along with Lum
 */
 
 #include <util/delay.h>
-#include <base.h>
+#include <dio.h>
 #include "shift_register.h"
 
 void sr_strobe_line(dio_t *line) {

shift-register/shift_register.h

@@ -14,7 +14,7 @@ You should have received a copy of the GNU General Public License along with Lum
 #ifndef __REG_H__
 #define __REG_H__
 
-#include <base.h>
+#include <dio.h>
 
 typedef struct SHIFT_REGISTER {
     dio_t output;

sk9822/sk9822.c

@@ -22,6 +22,7 @@ void send_byte(dio_t data_pin, dio_t clock_pin, uint8_t byte) {
 }
 
 void send_start(dio_t data_pin, dio_t clock_pin) {
+    dio_set(&clock_pin, 0);
     send_byte(data_pin, clock_pin, 0);
     send_byte(data_pin, clock_pin, 0);
     send_byte(data_pin, clock_pin, 0);
@@ -33,15 +34,21 @@ void send_term(dio_t data_pin, dio_t clock_pin) {
     send_byte(data_pin, clock_pin, 0xff);
     send_byte(data_pin, clock_pin, 0xff);
     send_byte(data_pin, clock_pin, 0xff);
+    dio_set(&clock_pin, 1);
 }
 
-void send_pixels(dio_t data_pin, dio_t clock_pin, rgb_t * pixels, uint8_t count) {
+void sk9822_init(sk9822_t *lights) {
-    send_start(data_pin, clock_pin);
+    dio_set_direction(&lights->data_pin, LINE_OUT);
-    for (uint8_t i = 0; i < count; i++) {
+    dio_set_direction(&lights->clock_pin, LINE_OUT);
-        send_byte(data_pin, clock_pin, 0xe0 + pixels[i].brightness);
+}
-        send_byte(data_pin, clock_pin, pixels[i].r);
+
-        send_byte(data_pin, clock_pin, pixels[i].b);
+void sk9822_send(sk9822_t *lights, rgb_t * pixels, uint8_t count) {
-        send_byte(data_pin, clock_pin, pixels[i].g);
+    send_start(lights->data_pin, lights->clock_pin);
-    }
+    for (uint8_t i = 0; i < count; i++) {
-    send_term(data_pin, clock_pin);
+        send_byte(lights->data_pin, lights->clock_pin, 0xe0 + pixels[i].brightness);
+        send_byte(lights->data_pin, lights->clock_pin, pixels[i].r);
+        send_byte(lights->data_pin, lights->clock_pin, pixels[i].b);
+        send_byte(lights->data_pin, lights->clock_pin, pixels[i].g);
+    }
+    send_term(lights->data_pin, lights->clock_pin);
 }

sk9822/sk9822.h

@@ -3,15 +3,15 @@ Copyright 2022, Savanni D'Gerinel <savanni@luminescent-dreams.com>
 
 This file is part of Savanni's AVR library.
 
-Lumeto is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+This AVR library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
 
-Lumeto is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+This AVR library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 
-You should have received a copy of the GNU General Public License along with Lumeto. If not, see <https://www.gnu.org/licenses/>.
+You should have received a copy of the GNU General Public License along with this AVR library. If not, see <https://www.gnu.org/licenses/>.
 */
 
 #include <avr/io.h>
-#include <base.h>
+#include <dio.h>
 
 #ifndef __SK9822_H__
 #define __SK9822_H__
@@ -23,6 +23,13 @@ typedef struct RGB_s {
     uint8_t b;
 } rgb_t;
 
-void send_pixels(dio_t data_pin, dio_t clock_pin, rgb_t *pixels, uint8_t count);
+typedef struct SK9822 {
+    dio_t data_pin;
+    dio_t clock_pin;
+} sk9822_t;
+
+void sk9822_init(sk9822_t *lights);
+
+void sk9822_send(sk9822_t *lights, rgb_t *pixels, uint8_t count);
 
 #endif

spi/spi.h

@@ -14,7 +14,7 @@ You should have received a copy of the GNU General Public License along with Lum
 #ifndef __MORSE_H__
 #define __MORSE_H__
 
-#include <base.h>
+#include <dio.h>
 #include <stdlib.h>
 
 typedef struct SPI {

timer/timer.h

@@ -0,0 +1,56 @@
+/*
+Copyright 2022, Savanni D'Gerinel <savanni@luminescent-dreams.com>
+
+This file is part of Savanni's AVR library.
+
+This AVR library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+
+This AVR library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with Lumeto. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef __TIMER_H__
+#define __TIMER_H__
+
+#include <avr/io.h>
+
+// ATmega16U4/32U4 Datasheet, table 14.4, page 133
+typedef enum {
+    normal,
+    pwm_phasecorrect_8bit,
+    pwm_phasecorrect_9bit,
+    pwm_phasecorrect_10bit,
+    ctc,
+    fast_pwm_8bit,
+    fast_pwm_9bit,
+    fast_pwm_10bit,
+    pwm_phase_and_frequency_correct_icrtop,
+    pwm_phase_and_frequency_correct_ocrtop,
+    pwm_phase_correct_icrtop,
+    pwm_phase_correct_ocrtop,
+    ctc_icr,
+    fast_pwm_icrtop,
+    fast_pwm_ocrtop,
+} timer_mode_t;
+
+// Clock prescaler selector, ATmega16U4/32U4 Datasheet, table 14.5, page 1354p
+typedef enum {
+    none,
+    clk_1,
+    clk_8,
+    clk_64,
+    clk_256,
+    clk_1024,
+    external_falling_edge,
+    external_rising_edge,
+} clock_select_t;
+
+typedef struct {
+    volatile uint8_t count_msb;
+    volatile uint8_t count_lsb;
+    volatile uint8_t top_msb;
+    volatile uint8_t top_lsb;
+} timer_16bit_t;
+
+#endif