commit 00ba6d1af6b2edfcdd0cf9fe0c91fcb5ec69b342
Author: Patrick Haßel <git@patrick-hassel.de>
Date:   Thu Aug 7 10:18:39 2025 +0200

    ModeTimer on console (no real leds, no wifi)

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..03f4a3c
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.pio
diff --git a/platformio.ini b/platformio.ini
new file mode 100644
index 0000000..4c3e9c8
--- /dev/null
+++ b/platformio.ini
@@ -0,0 +1,9 @@
+[env:MatrixDisplay2025]
+platform = espressif32
+board = esp32dev
+framework = arduino
+lib_deps = https://github.com/adafruit/Adafruit_NeoPixel
+upload_port = /dev/ttyACM0
+upload_speed = 921600
+monitor_port = /dev/ttyACM0
+monitor_speed = 115200
diff --git a/src/Button.h b/src/Button.h
new file mode 100644
index 0000000..a1b28b1
--- /dev/null
+++ b/src/Button.h
@@ -0,0 +1,71 @@
+#ifndef BUTTON_H
+#define BUTTON_H
+
+#include <Arduino.h>
+
+enum ButtonEvent {
+  BUTTON_PRESSED,
+  BUTTON_PRESSED_LONG,
+  BUTTON_RELEASED,
+  BUTTON_RELEASED_SHORT,
+  BUTTON_RELEASED_LONG,
+};
+
+class Button {
+
+public:
+
+  typedef void (*callback_t)(ButtonEvent event);
+
+private:
+
+  const uint8_t pin;
+
+  const callback_t callback;
+
+  bool lastState = false;
+
+  bool pressedLong = false;
+
+  unsigned long lastMillis = 0;
+
+public:
+
+  explicit Button(const uint8_t pin, const callback_t callback) : pin(pin), callback(callback) {
+    //
+  }
+
+  void setup() {
+    pinMode(pin, INPUT_PULLUP);
+    lastMillis = millis();
+    lastState = digitalRead(pin) == LOW;
+  }
+
+  void loop() {
+    const auto currentMillis = millis();
+    const auto currentState = digitalRead(pin) == LOW;
+    const auto duration = currentMillis - lastMillis;
+    if (lastState != currentState && duration >= 200) {
+      if (currentState) {
+        callback(BUTTON_PRESSED);
+      } else {
+        callback(BUTTON_RELEASED);
+        if (pressedLong) {
+          callback(BUTTON_RELEASED_LONG);
+        } else {
+          callback(BUTTON_RELEASED_SHORT);
+        }
+        pressedLong = false;
+      }
+      lastState = currentState;
+      lastMillis = currentMillis;
+    }
+    if (lastState && duration >= 3000 && !pressedLong) {
+      pressedLong = true;
+      callback(BUTTON_PRESSED_LONG);
+    }
+  }
+
+};
+
+#endif
diff --git a/src/Display.cpp b/src/Display.cpp
new file mode 100644
index 0000000..9eb7866
--- /dev/null
+++ b/src/Display.cpp
@@ -0,0 +1,414 @@
+#include "Display.h"
+
+#define __ false // NOLINT(*-reserved-identifier)
+#define XX true
+
+Color WHITE = {255, 255, 255};
+
+Color BLACK = {0, 0, 0};
+
+Color RED = {255, 0, 0};
+
+Color GREEN = {0, 255, 0};
+
+Color BLUE = {0, 0, 255};
+
+Color YELLOW = {255, 255, 0};
+
+Color CYAN = {0, 255, 255};
+
+Color MAGENTA = {255, 0, 255};
+
+Color ORANGE = {255, 127, 0};
+
+Color GREY = {128, 128, 128};
+
+const bool DOT7[][7][1] = {
+  {
+    {__},
+    {__},
+    {__},
+    {__},
+    {__},
+    {__},
+    {XX},
+  },
+  {
+    {__},
+    {__},
+    {__},
+    {__},
+    {__},
+    {XX},
+    {XX},
+  },
+  {
+    {__},
+    {XX},
+    {__},
+    {__},
+    {__},
+    {XX},
+    {__},
+  },
+  {
+    {__},
+    {XX},
+    {__},
+    {__},
+    {__},
+    {XX},
+    {XX},
+  },
+};
+
+const bool SPECIAL7[][7][3] = {
+  {
+    {__,__,__},
+    {__,__,__},
+    {__,__,__},
+    {__,__,__},
+    {__,__,__},
+    {__,__,__},
+    {__,__,__},
+  },
+  {
+    {__,__,__},
+    {__,__,__},
+    {__,__,__},
+    {XX,XX,XX},
+    {__,__,__},
+    {__,__,__},
+    {__,__,__},
+  },
+};
+
+const bool NUM7[][7][4] = {
+  {
+    {__, XX, XX, __},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {__, XX, XX, __},
+  },
+  {
+    {__, __, XX, XX},
+    {__, XX, __, XX},
+    {XX, __, __, XX},
+    {__, __, __, XX},
+    {__, __, __, XX},
+    {__, __, __, XX},
+    {__, __, __, XX},
+  },
+  {
+    {__, XX, XX, __},
+    {XX, __, __, XX},
+    {__, __, __, XX},
+    {__, __, XX, __},
+    {__, XX, __, __},
+    {XX, __, __, __},
+    {XX, XX, XX, XX},
+  },
+  {
+    {__, XX, XX, __},
+    {XX, __, __, XX},
+    {__, __, __, XX},
+    {__, __, XX, __},
+    {__, __, __, XX},
+    {XX, __, __, XX},
+    {__, XX, XX, __},
+  },
+  {
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, XX, XX, XX},
+    {__, __, __, XX},
+    {__, __, __, XX},
+    {__, __, __, XX},
+  },
+  {
+    {XX, XX, XX, XX},
+    {XX, __, __, __},
+    {XX, __, __, __},
+    {XX, XX, XX, __},
+    {__, __, __, XX},
+    {__, __, __, XX},
+    {XX, XX, XX, __},
+  },
+  {
+    {__, XX, XX, __},
+    {XX, __, __, __},
+    {XX, __, __, __},
+    {XX, XX, XX, __},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {__, XX, XX, __},
+  },
+  {
+    {XX, XX, XX, XX},
+    {__, __, __, XX},
+    {__, __, XX, __},
+    {__, XX, __, __},
+    {XX, __, __, __},
+    {XX, __, __, __},
+    {XX, __, __, __},
+  },
+  {
+    {__, XX, XX, __},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {__, XX, XX, __},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {__, XX, XX, __},
+  },
+  {
+    {__, XX, XX, __},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {__, XX, XX, XX},
+    {__, __, __, XX},
+    {__, __, __, XX},
+    {__, XX, XX, __},
+  },
+};
+
+const bool ALPHA7[][7][4] = {
+  {
+    {__, XX, XX, __},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, XX, XX, XX},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {XX, XX, XX, XX},
+    {XX, __, __, __},
+    {XX, __, __, __},
+    {XX, XX, XX, __},
+    {XX, __, __, __},
+    {XX, __, __, __},
+    {XX, XX, XX, XX},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {XX, XX, XX, __},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, XX, XX, __},
+    {XX, __, __, __},
+    {XX, __, __, __},
+    {XX, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, XX, XX, __},
+    {XX, __, __, __},
+    {XX, __, __, __},
+    {__, XX, XX, __},
+    {__, __, __, XX},
+    {__, __, __, XX},
+    {__, XX, XX, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {XX, __, __, XX},
+    {__, XX, XX, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+  {
+    {__, __, __, __},
+    {__, __, __, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, XX, XX, __},
+    {__, __, __, __},
+    {__, __, __, __},
+  },
+};
diff --git a/src/Display.h b/src/Display.h
new file mode 100644
index 0000000..97c2efb
--- /dev/null
+++ b/src/Display.h
@@ -0,0 +1,244 @@
+#ifndef DISPLAY_H
+#define DISPLAY_H
+
+#include <Adafruit_NeoPixel.h>
+
+enum Align {
+  ALIGN_LEFT, ALIGN_CENTER, ALIGN_RIGHT
+};
+
+enum Font {
+  FONT5, FONT7
+};
+
+struct Color {
+  uint8_t r, g, b;
+};
+
+extern Color WHITE;
+
+extern Color BLACK;
+
+extern Color RED;
+
+extern Color GREEN;
+
+extern Color BLUE;
+
+extern Color YELLOW;
+
+extern Color CYAN;
+
+extern Color MAGENTA;
+
+extern Color ORANGE;
+
+extern Color GREY;
+
+extern const bool DOT7[][7][1];
+
+extern const bool SPECIAL7[][7][3];
+
+extern const bool NUM7[][7][4];
+
+extern const bool ALPHA7[][7][4];
+
+class Display {
+
+  Adafruit_NeoPixel leds;
+
+  bool pixels[8 * 32]{};
+
+  static int mapPixel(const int x, const int y) {
+    return y * 32 + (y % 2 == 0 ? x : 31 - x);
+  }
+
+public:
+
+  explicit Display(const uint8_t pin): leds(8 * 32, pin,NEO_GRB + NEO_KHZ800) {
+    //
+  }
+
+  void setBrightness(int i) {
+#if LEDS_ENABLED
+    leds.setBrightness(max(0, min(i, 255)));
+#endif
+  }
+
+  void setup() {
+#if LEDS_ENABLED
+    leds.begin();
+#endif
+    for (int y = 0; y < 8; y++) {
+      for (int x = 0; x < 32; x++) {
+        pixels[mapPixel(x, y)] = false;
+      }
+    }
+    setBrightness(32);
+    clear();
+    show();
+  }
+
+  void show() {
+#if LEDS_ENABLED
+    leds.show();
+#endif
+  }
+
+  void setPixel(const int x, const int y, const Color &color) {
+    const auto index = mapPixel(x, y);
+    if (index >= 8 * 32) {
+      Serial.printf("[ERROR] No pixel at (%d, %d) = %d >= %d\n", x, y, index, 8 * 32);
+      return;
+    }
+#if LEDS_ENABLED
+    leds.setPixelColor(index, color.r, color.g, color.b);
+#endif
+    pixels[index] = color.r > 0 || color.g > 0 || color.b > 0;
+  }
+
+  void rect(const int x0, const int y0, const int w, const int h, const Color &color) {
+    for (int y = y0; y < y0 + h; y++) {
+      for (int x = x0; x < x0 + w; x++) {
+        setPixel(x, y, color);
+      }
+    }
+  }
+
+  void print(int x, const int y, const Align align, const Font font, const Color &color, const char *format, ...) {
+    char text[32];
+    va_list args;
+    va_start(args, format);
+    vsnprintf(text, sizeof text, format, args);
+    va_end(args);
+    const auto width = measure(text, font);
+    x = align == ALIGN_LEFT ? x : align == ALIGN_RIGHT ? x - width : x - width / 2;
+    for (const char *c = text; *c; c++) {
+      x += printChar(x, y, *c, font, color) + 1;
+    }
+  }
+
+  int printChar(const int x, const int y, const char c, const Font font, const Color &color) {
+    if (isDot(c)) {
+      if (c == '.') {
+        return printSymbol(x, y, 0, color, DOT7);
+      }
+      if (c == ',') {
+        return printSymbol(x, y, 1, color, DOT7);
+      }
+      if (c == ':') {
+        return printSymbol(x, y, 2, color, DOT7);
+      }
+      if (c == ';') {
+        return printSymbol(x, y, 3, color, DOT7);
+      }
+    }
+    if (isSpecial(c)) {
+      if (c == ' ') {
+        return printSymbol(x, y, 0, color, SPECIAL7);
+      }
+      if (c == '-') {
+        return printSymbol(x, y, 1, color, SPECIAL7);
+      }
+    }
+    if (isNumber(c)) {
+      return printSymbol(x, y, c - '0', color, NUM7);
+    }
+    if (isLower(c)) {
+      return printSymbol(x, y, c - 'a', color, ALPHA7);
+    }
+    if (isUpper(c)) {
+      return printSymbol(x, y, c - 'A', color, ALPHA7);
+    }
+    Serial.printf("UNKNOWN SYMBOL '%c'\n", c);
+    return 0;
+  }
+
+  template<int symbolHeight, int symbolWidth>
+  int printSymbol(const int x, const int y, const int index, const Color &color, const bool symbols[][symbolHeight][symbolWidth]) {
+    for (int innerY = 0; innerY < symbolHeight; innerY++) {
+      for (int innerX = 0; innerX < symbolWidth; innerX++) {
+        if (symbols[index][innerY][innerX]) {
+          setPixel(x + innerX, y + innerY, color);
+        }
+      }
+    }
+    return symbolWidth;
+  }
+
+  void clear() {
+    rect(0, 0, 32, 8, BLACK);
+  }
+
+  void log() const {
+    Serial.print("+");
+    for (int x = 0; x < 32; x++) {
+      Serial.print("--");
+    }
+    Serial.print("+\n");
+
+    for (int y = 0; y < 8; y++) {
+      Serial.print("|");
+      for (int x = 0; x < 32; x++) {
+        if (pixels[mapPixel(x, y)]) {
+          Serial.print("##");
+        } else {
+          Serial.print("  ");
+        }
+      }
+      Serial.print("|\n");
+    }
+
+    Serial.print("+");
+    for (int x = 0; x < 32; x++) {
+      Serial.print("--");
+    }
+    Serial.print("+\n");
+
+    Serial.print('\n');
+  }
+
+  static uint8_t measure(const char *text, const Font font) {
+    uint8_t width = 0;
+    for (const char *c = text; *c; c++) {
+      if (c != text) {
+        width++; // space between chars
+      }
+      width += getWidth(*c, font);
+    }
+    return width;
+  }
+
+  static uint8_t getWidth(const char c, const Font font) {
+    if (isDot(c)) {
+      return 1;
+    }
+    if (isSpecial(c)) {
+      return 3;
+    }
+    return font == FONT5 ? 3 : 4;
+  }
+
+  static bool isDot(const char c) {
+    return c == ':' || c == ';' || c == '.' || c == ',';
+  }
+
+  static bool isSpecial(const char c) {
+    return c == ' ' || c == '-';
+  }
+
+  static bool isNumber(const char c) {
+    return c >= '0' && c <= '9';
+  }
+
+  static bool isLower(const char c) {
+    return c >= 'a' && c <= 'z';
+  }
+
+  static bool isUpper(const char c) {
+    return c >= 'A' && c <= 'Z';
+  }
+
+};
+
+#endif
diff --git a/src/beep.h b/src/beep.h
new file mode 100644
index 0000000..fb6270f
--- /dev/null
+++ b/src/beep.h
@@ -0,0 +1,15 @@
+#ifndef BEEP_H
+#define BEEP_H
+
+#include <Arduino.h>
+
+inline void beepSet(const bool state) {
+  digitalWrite(2, state ? HIGH : LOW);
+}
+
+inline void beepSetup() {
+  pinMode(2,OUTPUT);
+  beepSet(false);
+}
+
+#endif
diff --git a/src/main.cpp b/src/main.cpp
new file mode 100644
index 0000000..c08ff2d
--- /dev/null
+++ b/src/main.cpp
@@ -0,0 +1,47 @@
+#include <WiFi.h>
+#include "Button.h"
+#include "mode/Mode.h"
+#include "mode/ModeTimer.h"
+
+Display display(33);
+
+ModeTimer mode;
+
+void buttonCallback(const ButtonEvent event) {
+  if (event == BUTTON_PRESSED) {
+    mode.buttonOK();
+  }
+  if (BUTTON_PRESSED_LONG) {
+    mode.buttonESC();
+  }
+}
+
+Button button(23, buttonCallback);
+
+void setup() {
+  WiFi.disconnect();
+  delay(500);
+  Serial.begin(115200);
+  Serial.println("\n\n\nStartup!");
+  beepSetup();
+  display.setup();
+  mode.init();
+}
+
+void loop() {
+  const uint64_t now = millis();
+  static uint64_t lastMillis = 0;
+  const uint64_t deltaMillis = now - lastMillis;
+  lastMillis = now;
+
+  mode.step(deltaMillis);
+  mode.draw(display);
+
+  const auto code = Serial.read();
+  if (code == ' ') {
+    mode.buttonOK();
+  }
+  if (code == 'x') {
+    mode.buttonESC();
+  }
+}
diff --git a/src/mode/Mode.h b/src/mode/Mode.h
new file mode 100644
index 0000000..8a3b474
--- /dev/null
+++ b/src/mode/Mode.h
@@ -0,0 +1,53 @@
+#ifndef MODE_H
+#define MODE_H
+
+#include <WString.h>
+#include <Preferences.h>
+
+#include "Display.h"
+
+class Mode {
+
+public:
+
+  virtual ~Mode() = default;
+
+  String getName() const {
+    return name;
+  }
+
+  virtual void init() {
+    //
+  }
+
+  virtual void step(uint64_t deltaMillis) {
+    //
+  }
+
+  virtual void draw(Display &display) {
+    //
+  }
+
+  virtual void buttonOK() {
+    //
+  }
+
+  virtual void buttonESC() {
+    //
+  }
+
+  virtual void stop() {
+    //
+  }
+
+protected:
+
+  const char *name;
+
+  explicit Mode(const char *name) : name(name) {
+    //
+  }
+
+};
+
+#endif
diff --git a/src/mode/ModeTimer.h b/src/mode/ModeTimer.h
new file mode 100644
index 0000000..2fd7717
--- /dev/null
+++ b/src/mode/ModeTimer.h
@@ -0,0 +1,193 @@
+#ifndef MODE_TIMER_H
+#define MODE_TIMER_H
+
+#include "beep.h"
+#include "Mode.h"
+#include "Rest.h"
+#include "Timer.h"
+
+enum Stage {
+  FIRST_HALF, SECOND_HALF, LAST_MINUTE, FINALE
+};
+
+class ModeTimer final : public Mode {
+
+  Timer countdown;
+
+  Timer flash;
+
+  Timer pause;
+
+  Timer beep;
+
+  bool dirty = true;
+
+  bool dirtyPrint = true;
+
+  Rest rest{0};
+
+  Rest last{0};
+
+public:
+
+  explicit ModeTimer()
+    : Mode("Timer"),
+      countdown("countdown", [this]() {
+        flash.start();
+        dirty = true;
+        dirtyPrint = true;
+      }),
+      flash("flash", [this]() {
+        dirty = true;
+        dirtyPrint = true;
+      }),
+      pause("pause", [this]() {
+        dirty = true;
+        dirtyPrint = true;
+      }),
+      beep("beep", [this]() { beepSet(beep.isEven()); }) {
+    //
+  }
+
+  void init() override {
+    Serial.printf("Mode INIT: %s\n", name);
+
+    Preferences preferences;
+    preferences.begin("Timer", true);
+    const auto configMillis = preferences.getULong("configMillis", 40 * 1000);
+    preferences.end();
+
+    beepSet(false);
+
+    countdown.stop();
+    flash.stop();
+    pause.stop();
+    beep.stop();
+
+    countdown.countConfig(configMillis, 1);
+    flash.countConfig(100, 19);
+    beep.countConfig(200, 1);
+    pause.foreverConfig(500);
+
+    dirty = true;
+    dirtyPrint = true;
+  }
+
+  void step(const uint64_t deltaMillis) override {
+    flash.step(deltaMillis);
+    pause.step(deltaMillis);
+    beep.step(deltaMillis);
+    if (!pause.isRunning()) {
+      countdown.step(deltaMillis);
+    }
+  }
+
+  void buttonOK() override {
+    if (flash.isRunning()) {
+      return;
+    }
+    if (!countdown.isRunning()) {
+      countdown.start();
+    } else {
+      pause.toggle();
+    }
+    dirty = true;
+    dirtyPrint = true;
+  }
+
+  void buttonESC() override {
+    init();
+  }
+
+  void draw(Display &display) override {
+    rest = Rest(countdown.getRestMillis());
+
+    display.clear();
+    if (flash.isRunning()) {
+      const auto state = flash.isEven();
+      if (state) {
+        display.rect(0, 0, 32, 8, WHITE);
+      }
+      beepSet(true);
+    } else {
+      if (countdown.isRunning()) {
+        if (pause.isRunning() && pause.isEven()) {
+          display.print(15, 0, ALIGN_CENTER, FONT7, BLUE, "PAUSE");
+        } else {
+          drawTime(display);
+        }
+      } else {
+        beepSet(false);
+        display.print(15, 0, ALIGN_CENTER, FONT7, RED, "-- : --");
+      }
+    }
+    if (dirty) {
+      dirty = false;
+      display.show();
+      if (dirtyPrint) {
+        dirtyPrint = false;
+        rest.log();
+        display.log();
+      }
+    }
+    last = rest;
+  }
+
+private:
+
+  void doBeep(const uint32_t count) {
+    beepSet(true);
+    beep.startCount(count * 2 - 1);
+  }
+
+  void drawTime(Display &display) {
+    Color color = RED;
+    Stage stage = FINALE;
+    if (rest.millisTotal > countdown.getConfigMillis() / 2) {
+      color = WHITE;
+      stage = FIRST_HALF;
+    } else if (rest.millisTotal > 15 * 1000) {
+      color = YELLOW;
+      stage = SECOND_HALF;
+    } else if (rest.millisTotal > 10 * 1000) {
+      color = ORANGE;
+      stage = LAST_MINUTE;
+    }
+
+    static int lastStage = stage;
+    if (lastStage != stage) {
+      if (stage == SECOND_HALF) {
+        doBeep(1);
+      } else if (stage == LAST_MINUTE) {
+        doBeep(2);
+      }
+      lastStage = stage;
+    }
+
+    if (rest.secondChanged(last)) {
+      if (stage == FINALE) {
+        doBeep(1);
+      }
+    }
+
+    if (rest.daysTotal > 0) {
+      display.print(16, 0, ALIGN_CENTER, FONT7, color, "%3d. %2d", rest.daysPart, rest.hoursPart);
+      dirty |= rest.hourChanged(last);
+      dirtyPrint = true;
+    } else if (rest.hoursTotal > 0) {
+      display.print(16, 0, ALIGN_CENTER, FONT7, color, "%2d:%02d:%02d", rest.hoursPart, rest.minutesPart, rest.secondsPart);
+      dirty |= rest.secondChanged(last);
+      dirtyPrint = true;
+    } else if (rest.minutesTotal > 0) {
+      display.print(16, 0, ALIGN_CENTER, FONT7, color, "%2d:%02d", rest.minutesPart, rest.secondsPart);
+      dirty |= rest.secondChanged(last);
+      dirtyPrint = true;
+    } else {
+      display.print(16, 0, ALIGN_CENTER, FONT7, color, "%2d.%d", rest.secondsPart, rest.decisPart);
+      dirty |= rest.deciChanged(last);
+      dirtyPrint |= rest.secondChanged(last);
+    }
+  }
+
+};
+#endif
diff --git a/src/mode/Rest.h b/src/mode/Rest.h
new file mode 100644
index 0000000..04a13dc
--- /dev/null
+++ b/src/mode/Rest.h
@@ -0,0 +1,66 @@
+#ifndef REST_H
+#define REST_H
+
+#include <cstdint>
+
+#include "ModeTimer.h"
+#include "ModeTimer.h"
+
+struct Rest {
+
+  uint64_t millisTotal;
+
+  uint64_t decisTotal;
+
+  uint64_t secondsTotal;
+
+  uint64_t minutesTotal;
+
+  uint64_t hoursTotal;
+
+  uint64_t daysTotal;
+
+  uint32_t decisPart;
+
+  uint32_t secondsPart;
+
+  uint32_t minutesPart;
+
+  uint32_t hoursPart;
+
+  uint32_t daysPart;
+
+  explicit Rest(const uint32_t millisTotal)
+    : millisTotal(millisTotal),
+      decisTotal(millisTotal / 100),
+      secondsTotal(decisTotal / 10),
+      minutesTotal(secondsTotal / 60),
+      hoursTotal(minutesTotal / 60),
+      daysTotal(hoursTotal / 24),
+      decisPart(decisTotal % 10),
+      secondsPart(secondsTotal % 60),
+      minutesPart(minutesTotal % 60),
+      hoursPart(hoursTotal % 24),
+      daysPart(daysTotal) {
+    //
+  }
+
+  bool deciChanged(const Rest &rest) const {
+    return decisTotal != rest.decisTotal;
+  }
+
+  bool secondChanged(const Rest &last) const {
+    return secondsTotal != last.secondsTotal;
+  }
+
+  bool hourChanged(const Rest &rest) const {
+    return hoursTotal != rest.hoursTotal;
+  }
+
+  void log() const {
+    Serial.printf("%3d.%02d:%02d:%02d.%d\n", daysPart, hoursPart, minutesPart, secondsPart, decisPart);
+  }
+
+};
+
+#endif
diff --git a/src/mode/Timer.h b/src/mode/Timer.h
new file mode 100644
index 0000000..2440514
--- /dev/null
+++ b/src/mode/Timer.h
@@ -0,0 +1,126 @@
+#ifndef TIMER_H
+#define TIMER_H
+
+class Timer {
+
+  const char *name;
+
+  std::function<void()> callback;
+
+  bool running = false;
+
+  bool forever = false;
+
+  uint64_t configCount = 0;
+
+  uint64_t configMillis = 0;
+
+  uint64_t restMillis = 0;
+
+  uint64_t restCount = 0;
+
+  uint64_t doneCount = 0;
+
+public:
+
+  explicit Timer(const char *name, std::function<void()> callback): name(name), callback(std::move(callback)) {
+    //
+  }
+
+  void foreverConfig(const uint64_t configMillis) {
+    this->configMillis = configMillis;
+    this->configCount = 1;
+    this->forever = true;
+    // Serial.printf("Timer(%s) CONFIG: %lld ms, FOREVER\n", name, configMillis);
+  }
+
+  void countConfig(const uint64_t configMillis, const uint64_t configCount) {
+    this->configMillis = configMillis;
+    this->configCount = configCount;
+    this->forever = false;
+    // Serial.printf("Timer(%s) CONFIG: %lld ms x %lld\n", name, configMillis, configCount);
+  }
+
+  void startCount(const uint64_t count) {
+    configCount = count;
+    start();
+  }
+
+  void start() {
+    if (configCount > 0 && configMillis > 0) {
+      doneCount = 0;
+      restCount = configCount;
+      restMillis = configMillis;
+      running = true;
+      // Serial.printf("Timer(%s) START\n", name);
+    } else {
+      // Serial.printf("Timer(%s) CANNOT START ZERO INTERVAL", name);
+      stop();
+    }
+  }
+
+  void stop() {
+    if (running || restCount > 0 || restMillis > 0) {
+      restCount = 0;
+      restMillis = 0;
+      running = false;
+      // Serial.printf("Timer(%s) STOP\n", name);
+    }
+  }
+
+  void step(uint64_t deltaMillis) {
+    auto ticks = 0;
+    while (running && restCount > 0 && deltaMillis > 0) {
+      if (restMillis > deltaMillis) {
+        restMillis -= deltaMillis;
+        break;
+      }
+      ticks++;
+      doneCount++;
+      if (forever) {
+        // Serial.printf("Timer(%s) TICK\n", name);
+      } else {
+        restCount--;
+        // Serial.printf("Timer(%s) TICK %lld/%lld\n", name, configCount - restCount, configCount);
+      }
+      deltaMillis -= restMillis;
+      restMillis = configMillis;
+      if (restCount == 0) {
+        stop();
+      }
+      if (callback) {
+        callback();
+      }
+    }
+    if (ticks > 1) {
+      // Serial.printf("[WARN] Skipped %d ticks\n", ticks - 1);
+    }
+  }
+
+  bool isRunning() const {
+    return running;
+  }
+
+  uint64_t getRestMillis() const {
+    return restMillis;
+  }
+
+  uint64_t getConfigMillis() const {
+    return configMillis;
+  }
+
+  void toggle() {
+    if (running) {
+      stop();
+    } else {
+      start();
+    }
+  }
+
+  bool isEven() const {
+    return doneCount % 2 == 0;
+  }
+
+};
+
+#endif