Fix #207 adjust OLED Brightness by attachDuringLongPress

adjust the OLED Brightness by "attachDuringLongPress" from "OneButton". It will cycle trough 0 to 254 as long as the button is pressed

src/main.cpp

@@ -136,6 +136,9 @@ Periodic ledPeriodic(ledBlinker);
 void userButtonPressed() {
     powerFSM.trigger(EVENT_PRESS);
 }
+void userButtonPressedLong(){
+    screen.adjustBrightness();
+}
 
 #ifndef NO_ESP32
 void initWifi()
@@ -197,10 +200,12 @@ void setup()
 #ifdef BUTTON_PIN
     userButton = OneButton(BUTTON_PIN, true, true);
     userButton.attachClick(userButtonPressed);
+    userButton.attachDuringLongPress(userButtonPressedLong);
 #endif
 #ifdef BUTTON_PIN_ALT
     userButtonAlt = OneButton(BUTTON_PIN_ALT, true, true);
     userButtonAlt.attachClick(userButtonPressed);
+    userButton.attachDuringLongPress(userButtonPressedLong);
 #endif
 #ifdef LED_PIN
     pinMode(LED_PIN, OUTPUT);

src/screen.cpp

@@ -514,6 +514,9 @@ void Screen::setup()
     // Store a pointer to Screen so we can get to it from static functions.
     ui.getUiState()->userData = this;
 
+    // Set the utf8 conversion function
+    dispdev.setFontTableLookupFunction(customFontTableLookup);
+
     // Add frames.
     static FrameCallback bootFrames[] = {drawBootScreen};
     static const int bootFrameCount = sizeof(bootFrames) / sizeof(bootFrames[0]);
@@ -720,9 +723,24 @@ void DebugInfo::drawFrame(OLEDDisplay *display, OLEDDisplayUiState *state, int16
     }
 
     const char *fields[] = {channelStr, nullptr};
-    uint32_t yo = drawRows(display, x, y + 12, fields);
+    uint32_t yo = drawRows(display, x, y + FONT_HEIGHT, fields);
 
     display->drawLogBuffer(x, yo);
 }
 
+//adjust Brightness cycle trough 1 to 254 as long as attachDuringLongPress is true
+void Screen::adjustBrightness(){
+    if (brightness == 254)
+    {
+        brightness = 0;
+    } else {
+        brightness++;    
+    }
+    int width = brightness / 1.984375;
+    dispdev.drawRect( 0, 30, 128, 4);
+    dispdev.fillRect(0, 30, width, 4);
+    dispdev.display();
+    dispdev.setBrightness(brightness);
+}
+
 } // namespace meshtastic

src/screen.h

@@ -117,6 +117,10 @@ class Screen : public PeriodicTask
     /// Handles a button press.
     void onPress() { enqueueCmd(CmdItem{.cmd = Cmd::ON_PRESS}); }
 
+    // Implementation to Adjust Brightness
+    void adjustBrightness();
+    int brightness = 150;
+
     /// Starts showing the Bluetooth PIN screen.
     //
     // Switches over to a static frame showing the Bluetooth pairing screen
@@ -149,6 +153,37 @@ class Screen : public PeriodicTask
         }
     }
 
+    /// Overrides the default utf8 character conversion, to replace empty space with question marks
+    static char customFontTableLookup(const uint8_t ch) {
+        // UTF-8 to font table index converter
+        // Code form http://playground.arduino.cc/Main/Utf8ascii
+        static uint8_t LASTCHAR;
+        static bool SKIPREST;   // Only display a single unconvertable-character symbol per sequence of unconvertable characters
+
+        if (ch < 128) { // Standard ASCII-set 0..0x7F handling
+            LASTCHAR = 0;
+            SKIPREST = false;
+            return ch;
+        }
+
+        uint8_t last = LASTCHAR;   // get last char
+        LASTCHAR = ch;
+
+        switch (last) {    // conversion depnding on first UTF8-character
+            case 0xC2: { SKIPREST = false; return (uint8_t) ch; }
+            case 0xC3: { SKIPREST = false; return (uint8_t) (ch | 0xC0); }
+        }
+
+        // We want to strip out prefix chars for two-byte char formats
+        if (ch == 0xC2 || ch == 0xC3 || ch == 0x82) return (uint8_t) 0;
+
+        // If we already returned an unconvertable-character symbol for this unconvertable-character sequence, return NULs for the rest of it
+        if (SKIPREST) return (uint8_t) 0;
+        SKIPREST = true;
+
+        return (uint8_t) 191; // otherwise: return ¿ if character can't be converted (note that the font map we're using doesn't stick to standard EASCII codes)
+    }
+
     /// Returns a handle to the DebugInfo screen.
     //
     // Use this handle to set things like battery status, user count, GPS status, etc.