Show "sleeping" on eink while in deep sleep

src/graphics/Screen.cpp

@@ -85,13 +85,16 @@ static uint16_t displayWidth, displayHeight;
 #define SCREEN_TRANSITION_MSECS 300
 #endif
 
-static void drawBootScreen(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y)
+/**
+ * Draw the icon with extra info printed around the corners
+ */
+static void drawIconScreen(const char *upperMsg, OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y)
 {
     // draw an xbm image.
     // Please note that everything that should be transitioned
     // needs to be drawn relative to x and y
 
-    // draw centered left to right and centered above the one line of app text
+    // draw centered icon left to right and centered above the one line of app text
     display->drawXbm(x + (SCREEN_WIDTH - icon_width) / 2, y + (SCREEN_HEIGHT - FONT_HEIGHT_MEDIUM - icon_height) / 2 + 2,
                      icon_width, icon_height, (const uint8_t *)icon_bits);
 
@@ -101,15 +104,31 @@ static void drawBootScreen(OLEDDisplay *display, OLEDDisplayUiState *state, int1
     display->drawString(x + getStringCenteredX(title), y + SCREEN_HEIGHT - FONT_HEIGHT_MEDIUM, title);
     display->setFont(FONT_SMALL);
 
-    const char *region = myRegion ? myRegion->name : NULL;
-    if (region)
-        display->drawString(x + 0, y + 0, region);
+    // Draw region in upper left
+    if (upperMsg)
+        display->drawString(x + 0, y + 0, upperMsg);
 
+    // Draw version in upper right
     char buf[16];
     snprintf(buf, sizeof(buf), "%s",
              xstr(APP_VERSION)); // Note: we don't bother printing region or now, it makes the string too long
     display->drawString(x + SCREEN_WIDTH - display->getStringWidth(buf), y + 0, buf);
     screen->forceDisplay();
+
+    // FIXME - draw serial # somewhere?
+}
+
+static void drawBootScreen(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y)
+{
+    // Draw region in upper left
+    const char *region = myRegion ? myRegion->name : NULL;
+    drawIconScreen(region, display, state, x, y);
+}
+
+/// Used on eink displays while in deep sleep
+static void drawSleepScreen(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y)
+{
+    drawIconScreen("Sleeping...", display, state, x, y);
 }
 
 static void drawFrameBluetooth(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y)
@@ -600,6 +619,21 @@ Screen::Screen(uint8_t address, int sda, int scl) : OSThread("Screen"), cmdQueue
     cmdQueue.setReader(this);
 }
 
+/**
+ * Prepare the display for the unit going to the lowest power mode possible.  Most screens will just
+ * poweroff, but eink screens will show a "I'm sleeping" graphic, possibly with a QR code
+ */
+void Screen::doDeepSleep()
+{
+#ifdef HAS_EINK
+    static FrameCallback sleepFrames[] = {drawSleepScreen};
+    static const int sleepFrameCount = sizeof(sleepFrames) / sizeof(sleepFrames[0]);
+    ui.setFrames(sleepFrames, sleepFrameCount);
+    ui.update();
+#endif
+    setOn(false);
+}
+
 void Screen::handleSetOn(bool on)
 {
     if (!useDisplay)

src/graphics/Screen.h

@@ -99,6 +99,12 @@ class Screen : public concurrency::OSThread
             enqueueCmd(ScreenCmd{.cmd = on ? Cmd::SET_ON : Cmd::SET_OFF});
     }
 
+    /**
+     * Prepare the display for the unit going to the lowest power mode possible.  Most screens will just 
+     * poweroff, but eink screens will show a "I'm sleeping" graphic, possibly with a QR code
+     */
+    void doDeepSleep();
+
     /// Handles a button press.
     void onPress() { enqueueCmd(ScreenCmd{.cmd = Cmd::ON_PRESS}); }
 

src/sleep.cpp

@@ -149,7 +149,7 @@ void doDeepSleep(uint64_t msecToWake)
     waitEnterSleep();
     notifyDeepSleep.notifyObservers(NULL);
 
-    screen->setOn(false); // datasheet says this will draw only 10ua
+    screen->doDeepSleep(); // datasheet says this will draw only 10ua
 
     nodeDB.saveToDisk();