diff --git a/src/button.cpp b/src/button.cpp
new file mode 100644
index 0000000..32e2466
--- /dev/null
+++ b/src/button.cpp
@@ -0,0 +1,38 @@
+#include "button.h"
+
+#include <Arduino.h>
+#include "countdown.h"
+
+bool buttonLastState = false;
+
+bool buttonLongPressed = false;
+
+unsigned long buttonLastMillis = 0;
+
+void buttonSetup() {
+  pinMode(25, INPUT_PULLUP);
+  buttonLastState = digitalRead(25) == LOW;
+  buttonLastMillis = millis();
+}
+
+void buttonLoop() {
+  const auto currentMillis = millis();
+  const auto durationMillis = currentMillis - buttonLastMillis;
+  if (durationMillis >= 100) {
+    const auto currentState = digitalRead(25) == LOW;
+    if (buttonLastState != currentState) {
+      buttonLastState = currentState;
+      buttonLastMillis = currentMillis;
+      buttonLongPressed = false;
+      if (!buttonLastState) {
+        if (durationMillis < 1000) {
+          countdownShortPress();
+        }
+      }
+    }
+  }
+  if (buttonLastState && currentMillis - buttonLastMillis >= 1000 && !buttonLongPressed) {
+    buttonLongPressed = true;
+    countdownLongPress();
+  }
+}
\ No newline at end of file
diff --git a/src/button.h b/src/button.h
new file mode 100644
index 0000000..61b71bb
--- /dev/null
+++ b/src/button.h
@@ -0,0 +1,8 @@
+#ifndef WS2812B_BUTTON_H
+#define WS2812B_BUTTON_H
+
+void buttonSetup();
+
+void buttonLoop();
+
+#endif
diff --git a/src/countdown.cpp b/src/countdown.cpp
new file mode 100644
index 0000000..db422bf
--- /dev/null
+++ b/src/countdown.cpp
@@ -0,0 +1,173 @@
+#include "countdown.h"
+
+#include "display.h"
+
+enum State {
+  CONFIG, READY, RUNNING, PAUSED, END
+};
+
+State state = CONFIG;
+
+long configMillis = 6 * 60 * 1000;
+
+long rest = configMillis;
+
+unsigned long last = 0;
+
+void updateTime() {
+  if (state != RUNNING) {
+    return;
+  }
+  const auto now = max(1UL, millis());
+  if (last != 0) {
+    const auto diff = now - last;
+    rest -= (long) diff;
+    if (rest < 0) {
+      rest = 0;
+    }
+  }
+  last = now;
+}
+
+void drawDashes() {
+  displayClear();
+  drawChar(0, '-', true, RED);
+  drawChar(1, '-', true, RED);
+  drawChar(2, '-', true, RED);
+  drawChar(3, '-', true, RED);
+  displayShow();
+}
+
+void drawWhite() {
+  displayClear();
+  drawChar(0, '8', true, WHITE);
+  drawChar(1, '8', true, WHITE);
+  drawDots(WHITE, WHITE, WHITE, WHITE);
+  drawChar(2, '8', true, WHITE);
+  drawChar(3, '8', true, WHITE);
+  displayShow();
+}
+
+void drawBlack() {
+  displayClear();
+  displayShow();
+}
+
+void drawSequence() {
+  for (int x = 0; x < 3; ++x) {
+    for (int i = 0; i < 2; ++i) {
+      drawWhite();
+      delay(100);
+      drawBlack();
+      delay(100);
+    }
+    drawDashes();
+    delay(500);
+  }
+}
+
+void setState(State newState) {
+  if (state == newState) {
+    return;
+  }
+
+  state = newState;
+  const char *name;
+  switch (state) {
+    case CONFIG:
+      rest = configMillis;
+      name = "CONFIG";
+      break;
+    case READY:
+      rest = configMillis;
+      name = "READY";
+      break;
+    case RUNNING:
+      last = millis();
+      name = "RUNNING";
+      break;
+    case PAUSED:
+      name = "PAUSED";
+      break;
+    case END:
+      name = "END";
+      break;
+    default:
+      name = "[???]";
+      break;
+  }
+  Serial.printf("Mode: %s\n", name);
+}
+
+void countdownUpdate() {
+  switch (state) {
+    case CONFIG:
+      drawMillis(rest, MAGENTA);
+      break;
+    case READY:
+      drawMillis(rest, GREEN);
+      break;
+    case RUNNING: {
+      if (rest > 0) {
+        const auto color = rest >= 60000 ? WHITE : (rest >= 10000 ? YELLOW : RED);
+        drawMillis(rest, color);
+      } else {
+        drawSequence();
+        setState(END);
+      }
+      break;
+    }
+    case PAUSED:
+      drawMillis(rest, BLUE);
+      break;
+    case END:
+      drawDashes();
+      break;
+  }
+}
+
+void countdownSetup() {
+  setState(READY);
+}
+
+void countdownLoop() {
+  updateTime();
+  countdownUpdate();
+}
+
+void countdownLongPress() {
+  switch (state) {
+    case CONFIG:
+      setState(READY);
+      break;
+    case READY:
+    case END:
+      setState(CONFIG);
+      break;
+    case RUNNING:
+    case PAUSED:
+      setState(READY);
+      break;
+  }
+}
+
+void countdownShortPress() {
+  switch (state) {
+    case CONFIG: {
+      auto seconds = (configMillis / 30000) * 30 % (15 * 60) + 30;
+      configMillis = seconds * 1000;
+      rest = configMillis;
+      break;
+    }
+    case RUNNING:
+      setState(PAUSED);
+      break;
+    case READY:
+    case PAUSED:
+      setState(RUNNING);
+      break;
+    case END:
+      setState(READY);
+      break;
+  }
+}
\ No newline at end of file
diff --git a/src/countdown.h b/src/countdown.h
new file mode 100644
index 0000000..6e3997b
--- /dev/null
+++ b/src/countdown.h
@@ -0,0 +1,12 @@
+#ifndef WS2812B_COUNTDOWN_H
+#define WS2812B_COUNTDOWN_H
+
+void countdownSetup();
+
+void countdownLoop();
+
+void countdownLongPress();
+
+void countdownShortPress();
+
+#endif
diff --git a/src/display.cpp b/src/display.cpp
index af40895..a93fccf 100644
--- a/src/display.cpp
+++ b/src/display.cpp
@@ -1,11 +1,18 @@
 #include "display.h"
 
+#define DIGIT_COUNT         4
 #define SEGMENTS_PER_DIGIT  7
 #define LEDS_PER_SEGMENT    6
 #define LEDS_PER_DOT        2
 #define DOT_COUNT           4
 #define DOTS_AFTER_DIGIT    1
 
+#define GPIO                26
+#define PIXELS              (DIGIT_COUNT * SEGMENTS_PER_DIGIT * LEDS_PER_SEGMENT + DOT_COUNT * LEDS_PER_DOT)
+#define BRIGHTNESS          32
+
+Adafruit_NeoPixel pixels(PIXELS, GPIO, NEO_GRB + NEO_KHZ800);
+
 uint8_t CHARS[] = {
     0b11111100, // 0
     0b00110000, // 1
@@ -50,11 +57,26 @@ uint8_t mapChar(char c) {
   return 0;
 }
 
-void drawChar(Adafruit_NeoPixel& pixels, int digit, char c, const Color& color) {
-  drawChar(pixels, digit, c, true, color);
+void displaySetup() {
+  pixels.begin();
+  pixels.setBrightness(BRIGHTNESS);
+  pixels.clear();
+  pixels.show();
 }
 
-void drawChar(Adafruit_NeoPixel& pixels, int digit, char c, bool showIfZero, const Color& color) {
+void displayClear() {
+  pixels.clear();
+}
+
+void displayShow() {
+  pixels.show();
+}
+
+void drawChar(int digit, char c, const Color& color) {
+  drawChar(digit, c, true, color);
+}
+
+void drawChar(int digit, char c, bool showIfZero, const Color& color) {
   if (c == '0' && !showIfZero) {
     return;
   }
@@ -75,55 +97,57 @@ void drawChar(Adafruit_NeoPixel& pixels, int digit, char c, bool showIfZero, con
   }
 }
 
-void drawNumber(Adafruit_NeoPixel& pixels, int digit, int number, bool zero, const Color& color) {
+void drawNumber(int digit, int number, bool zero, const Color& color) {
   const char ten = '0' + (number / 10 % 10);
   const char one = '0' + (number % 10);
-  drawChar(pixels, digit + 0, ten, zero, color);
-  drawChar(pixels, digit + 1, one, true, color);
+  drawChar(digit + 0, ten, zero, color);
+  drawChar(digit + 1, one, true, color);
 }
 
-void drawDot(Adafruit_NeoPixel& pixels, int dot, const Color& c) {
+void drawDot(int dot, const Color& c) {
   int index = 2 * SEGMENTS_PER_DIGIT * LEDS_PER_SEGMENT + dot * LEDS_PER_DOT;
   pixels.setPixelColor(index + 0, c.r, c.g, c.b);
   pixels.setPixelColor(index + 1, c.r, c.g, c.b);
 }
 
-void drawDots(Adafruit_NeoPixel& pixels, const Color& bottom, const Color& middleBottom, const Color& middleTop, const Color& top) {
-  drawDot(pixels, 0, bottom);
-  drawDot(pixels, 1, middleBottom);
-  drawDot(pixels, 2, middleTop);
-  drawDot(pixels, 3, top);
+void drawDots(const Color& bottom, const Color& middleBottom, const Color& middleTop, const Color& top) {
+  drawDot(0, bottom);
+  drawDot(1, middleBottom);
+  drawDot(2, middleTop);
+  drawDot(3, top);
 }
 
-void drawMillis(Adafruit_NeoPixel& pixels, const unsigned long millisTotal, const Color& color) {
+void drawMillisDeci(unsigned long millisTotal, const Color& color) {
   const auto secondsTotal = millisTotal / 1000;
   const auto minutes = (int) secondsTotal / 60;
   const auto seconds = (int) secondsTotal % 60;
+  const auto deci = (int) millisTotal / 100 % 10;
 
+  pixels.clear();
   if (minutes > 0) {
-    static auto lastSeconds = -1;
-    if (lastSeconds == seconds) {
-      return;
-    }
-    lastSeconds = seconds;
-
-    Serial.printf("%2d:%02d\n", minutes, seconds);
-
-    pixels.clear();
-    drawNumber(pixels, 0, minutes, false, color);
-    drawDots(pixels, BLACK, color, color, BLACK);
-    drawNumber(pixels, 2, seconds, true, color);
-    pixels.show();
+    drawNumber(0, minutes, false, color);
+    drawDots(BLACK, color, color, BLACK);
+    drawNumber(2, seconds, true, color);
   } else {
-    const auto deci = (int) millisTotal / 100 % 10;
-    Serial.printf("%2d.%02d\n", seconds, deci);
-
-    pixels.clear();
     if (seconds > 0) {
-      drawNumber(pixels, 0, seconds, false, color);
-      drawDots(pixels, color, BLACK, BLACK, BLACK);
+      drawNumber(0, seconds, false, color);
+      drawDots(color, BLACK, BLACK, BLACK);
     }
-    drawChar(pixels, 2, '0' + deci, true, color);
-    pixels.show();
+    drawChar(2, '0' + deci, true, color);
   }
+  pixels.show();
+}
+
+void drawMillis(unsigned long millisTotal, const Color& color) {
+  const auto secondsTotal = (unsigned long) ceil(millisTotal / 1000.0);
+  const auto minutes = (int) secondsTotal / 60;
+  const auto seconds = (int) secondsTotal % 60;
+
+  pixels.clear();
+  if (minutes > 0) {
+    drawNumber(0, minutes, false, color);
+    drawDots(BLACK, color, color, BLACK);
+  }
+  drawNumber(2, seconds, minutes > 0, color);
+  pixels.show();
 }
diff --git a/src/display.h b/src/display.h
index b2d00cf..713233b 100644
--- a/src/display.h
+++ b/src/display.h
@@ -5,14 +5,22 @@
 
 #include "Color.h"
 
-void drawChar(Adafruit_NeoPixel& pixels, int digit, char c, const Color& color);
+void displaySetup();
 
-void drawChar(Adafruit_NeoPixel& pixels, int digit, char c, bool showIfZero, const Color& color);
+void displayClear();
 
-void drawNumber(Adafruit_NeoPixel& pixels, int digit, int number, bool zero, const Color& color);
+void displayShow();
 
-void drawDots(Adafruit_NeoPixel& pixels, const Color& bottom, const Color& middleBottom, const Color& middleTop, const Color& top);
+void drawChar(int digit, char c, const Color& color);
 
-void drawMillis(Adafruit_NeoPixel& pixels, unsigned long millisTotal, const Color& color);
+void drawChar(int digit, char c, bool showIfZero, const Color& color);
+
+void drawNumber(int digit, int number, bool zero, const Color& color);
+
+void drawDots(const Color& bottom, const Color& middleBottom, const Color& middleTop, const Color& top);
+
+void drawMillisDeci(unsigned long millisTotal, const Color& color);
+
+void drawMillis(unsigned long millisTotal, const Color& color);
 
 #endif
diff --git a/src/main.cpp b/src/main.cpp
index f8f791f..64376c9 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,93 +1,17 @@
 #include "display.h"
-
-#define GPIO        26
-#define PIXELS      (4 * 7 * 6 + 4 * 4)
-#define BRIGHTNESS  32
-
-Adafruit_NeoPixel pixels(PIXELS, GPIO, NEO_GRB + NEO_KHZ800);
+#include "button.h"
+#include "countdown.h"
 
 void setup() {
   delay(500);
   Serial.begin(115200);
   Serial.println("\n\n\nstartup");
-  pixels.begin();
-  pixels.setBrightness(BRIGHTNESS);
-  pixels.clear();
-  pixels.show();
-}
-
-long configCountdownMillis = 6 * 60 * 1000;
-
-long rest = configCountdownMillis;
-
-unsigned long last = 0;
-
-void updateTime() {
-  const auto now = max(1UL, millis());
-  if (last != 0) {
-    const auto diff = now - last;
-    rest -= (long) diff;
-    if (rest < 0) {
-      rest = 0;
-    }
-  }
-  last = now;
-}
-
-bool running = true;
-
-void dashes() {
-  pixels.clear();
-  drawChar(pixels, 0, '-', true, RED);
-  drawChar(pixels, 1, '-', true, RED);
-  drawChar(pixels, 2, '-', true, RED);
-  drawChar(pixels, 3, '-', true, RED);
-  pixels.show();
-}
-
-void white() {
-  pixels.clear();
-  drawChar(pixels, 0, '8', true, WHITE);
-  drawChar(pixels, 1, '8', true, WHITE);
-  drawDots(pixels, WHITE, WHITE, WHITE, WHITE);
-  drawChar(pixels, 2, '8', true, WHITE);
-  drawChar(pixels, 3, '8', true, WHITE);
-  pixels.show();
-}
-
-void black() {
-  pixels.clear();
-  pixels.show();
-}
-
-void endSequence() {
-  for (int x = 0; x < 3; ++x) {
-    for (int i = 0; i < 2; ++i) {
-      white();
-      delay(100);
-      black();
-      delay(100);
-    }
-    dashes();
-    delay(500);
-  }
-}
-
-void showTime() {
-  if (!running) {
-    return;
-  }
-  if (rest > 0) {
-    const auto color = rest >= 60000 ? WHITE : (rest >= 10000 ? YELLOW : RED);
-    drawMillis(pixels, rest, color);
-  } else {
-    running = false;
-    Serial.println("END");
-    endSequence();
-  }
+  buttonSetup();
+  displaySetup();
+  countdownSetup();
 }
 
 void loop() {
-  updateTime();
-  showTime();
+  buttonLoop();
+  countdownLoop();
 }