Added a menu to check info

include/menu.h

@@ -0,0 +1,28 @@
+#ifndef MENU_H
+#define MENU_H
+
+#include <Arduino.h>
+#include <U8g2lib.h>
+
+enum class MenuAction
+{
+  ShowHelloWorld,
+  BackToCarousel
+};
+
+class Menu
+{
+public:
+  Menu();
+  void draw(U8G2 &u8g2);
+  void nextOption();
+  MenuAction select();
+  bool consumeDirty();
+  void requestRedraw();
+
+private:
+  size_t selectedIndex_;
+  bool dirty_;
+};
+
+#endif

include/screens.h

@@ -6,6 +6,7 @@
 #include "am2302_sensor.h"
 
 void drawScreen1(U8G2 &u8g2);
+void drawHelloWorldScreen(U8G2 &u8g2);
 void setEnvironmentReading(Am2302Reading reading);
 void drawEnvironmentScreen(U8G2 &u8g2);
 void drawWeatherIconScreen(U8G2 &u8g2);

src/main.cpp

@@ -4,23 +4,37 @@
 
 #include "am2302_sensor.h"
 #include "carousel.h"
+#include "menu.h"
 #include "screens.h"
 
 U8G2_SH1106_128X64_NONAME_F_HW_I2C u8g2(U8G2_R2, U8X8_PIN_NONE);
 
 int lastButtonNextState = LOW;
+int lastButtonSelectState = LOW;
 uint8_t buttonNext = A4;
+uint8_t buttonSelect = A5;
 Am2302Sensor am2302(A3);
 
+enum class AppMode
+{
+  Carousel,
+  Menu,
+  HelloWorld
+};
+
 Screen screens[] = {
   { drawScreen1 },
   { drawEnvironmentScreen },
   { drawWeatherIconScreen }
 };
 Carousel carousel(screens, sizeof(screens) / sizeof(screens[0]));
+Menu menu;
+AppMode appMode = AppMode::Carousel;
+bool appDirty = true;
 
 void setup() {
   pinMode(buttonNext, INPUT);
+  pinMode(buttonSelect, INPUT);
   am2302.begin();
 
   u8g2.begin();
@@ -28,24 +42,117 @@ void setup() {
   u8g2.sendBuffer();
 }
 
+void openMenu()
+{
+  appMode = AppMode::Menu;
+  menu.requestRedraw();
+  appDirty = true;
+}
+
+void selectMenuOption()
+{
+  switch (menu.select()) {
+    case MenuAction::ShowHelloWorld:
+      appMode = AppMode::HelloWorld;
+      break;
+    case MenuAction::BackToCarousel:
+      appMode = AppMode::Carousel;
+      carousel.requestRedraw();
+      break;
+  }
+
+  appDirty = true;
+}
+
+void handleNextButton()
+{
+  switch (appMode) {
+    case AppMode::Carousel:
+      carousel.nextScreen();
+      break;
+    case AppMode::Menu:
+      menu.nextOption();
+      break;
+    case AppMode::HelloWorld:
+      break;
+  }
+}
+
+void handleSelectButton()
+{
+  switch (appMode) {
+    case AppMode::Carousel:
+    case AppMode::HelloWorld:
+      openMenu();
+      break;
+    case AppMode::Menu:
+      selectMenuOption();
+      break;
+  }
+}
+
+bool displayNeedsRedraw()
+{
+  if (appDirty) {
+    appDirty = false;
+    return true;
+  }
+
+  switch (appMode) {
+    case AppMode::Carousel:
+      return carousel.consumeDirty();
+    case AppMode::Menu:
+      return menu.consumeDirty();
+    case AppMode::HelloWorld:
+      return false;
+  }
+
+  return false;
+}
+
+void drawActiveView()
+{
+  switch (appMode) {
+    case AppMode::Carousel:
+      carousel.draw(u8g2);
+      break;
+    case AppMode::Menu:
+      menu.draw(u8g2);
+      break;
+    case AppMode::HelloWorld:
+      drawHelloWorldScreen(u8g2);
+      break;
+  }
+}
+
 void loop(){
   const unsigned long now = millis();
-  carousel.update(now);
+  if (appMode == AppMode::Carousel) {
+    carousel.update(now);
+  }
 
   if (am2302.update(now)) {
     setEnvironmentReading(am2302.reading());
-    carousel.requestRedraw();
+    if (appMode == AppMode::Carousel) {
+      carousel.requestRedraw();
+    }
   }
 
-  const int currentButtonState = digitalRead(buttonNext);
-  if (lastButtonNextState == LOW && currentButtonState == HIGH) {
-      carousel.nextScreen();
+  const int currentButtonNextState = digitalRead(buttonNext);
+  if (lastButtonNextState == LOW && currentButtonNextState == HIGH) {
+      handleNextButton();
   }
-  lastButtonNextState = currentButtonState;
+  lastButtonNextState = currentButtonNextState;
 
-  if (carousel.consumeDirty()) {
+  const int currentButtonSelectState = digitalRead(buttonSelect);
+  if (lastButtonSelectState == LOW && currentButtonSelectState == HIGH) {
+      handleSelectButton();
+  }
+  lastButtonSelectState = currentButtonSelectState;
+
+  if (displayNeedsRedraw()) {
     u8g2.clearBuffer();
-    carousel.draw(u8g2);
+    drawActiveView();
     u8g2.sendBuffer();
   }
 

src/menu.cpp

@@ -0,0 +1,64 @@
+#include "menu.h"
+
+namespace
+{
+const char *menuOptions[] = {
+  "Hello world",
+  "Back"
+};
+
+const size_t menuOptionCount = sizeof(menuOptions) / sizeof(menuOptions[0]);
+
+MenuAction actionForIndex(size_t index)
+{
+  switch (index) {
+    case 0:
+      return MenuAction::ShowHelloWorld;
+    default:
+      return MenuAction::BackToCarousel;
+  }
+}
+}
+
+Menu::Menu()
+    : selectedIndex_(0),
+      dirty_(true) {}
+
+void Menu::draw(U8G2 &u8g2)
+{
+  u8g2.setFont(u8g2_font_6x12_tr);
+  u8g2.drawStr(0, 12, "Menu");
+
+  for (size_t i = 0; i < menuOptionCount; i++) {
+    const uint8_t y = 32 + (i * 18);
+    if (i == selectedIndex_) {
+      u8g2.drawStr(0, y, ">");
+    }
+    u8g2.drawStr(12, y, menuOptions[i]);
+  }
+
+  dirty_ = false;
+}
+
+void Menu::nextOption()
+{
+  selectedIndex_ = (selectedIndex_ + 1) % menuOptionCount;
+  dirty_ = true;
+}
+
+MenuAction Menu::select()
+{
+  return actionForIndex(selectedIndex_);
+}
+
+bool Menu::consumeDirty()
+{
+  const bool d = dirty_;
+  dirty_ = false;
+  return d;
+}
+
+void Menu::requestRedraw()
+{
+  dirty_ = true;
+}

src/screens.cpp

@@ -33,6 +33,13 @@ void drawScreen1(U8G2 &u8g2)
   u8g2.drawStr(0, 20, "Screen 1");
 }
 
+void drawHelloWorldScreen(U8G2 &u8g2)
+{
+  u8g2.setFont(u8g2_font_ncenB14_tr);
+  u8g2.drawStr(0, 30, "Hello");
+  u8g2.drawStr(0, 54, "world");
+}
+
 void setEnvironmentReading(Am2302Reading reading)
 {
   environmentReading = reading;