C6L: Integrate UIColor framework, add variant README, improve comments

Author: vistalba

src/helpers/ui/DisplayDriver.h

@@ -3,19 +3,27 @@
 #include <stdint.h>
 #include <string.h>
 
+// MarqueeScroller: Handles text scrolling for small displays (e.g., 64x48 OLED)
+// Used by companion radio UI to display long messages that don't fit on screen
 struct MarqueeScroller {
-  int offset = 0;
-  unsigned long next_time = 0;
-  bool paused = true;
+  int offset = 0;              // Current scroll offset in pixels
+  unsigned long next_time = 0; // Next scroll update time (millis)
+  bool paused = true;          // Scroll paused state
 
+  // Reset scroller to initial state
   void reset() {
     offset = 0;
     next_time = 0;
     paused = true;
   }
 
-  // Call once per loop iteration to advance the scroll.
-  // textW/displayW in pixels, now = millis().
+  // Update scroll position - call once per loop iteration
+  // Parameters:
+  //   textW - width of text in pixels
+  //   displayW - width of display in pixels
+  //   now - current time from millis()
+  //   speed_ms - milliseconds between scroll steps (default: 150ms)
+  //   pause_ms - milliseconds to pause before scrolling starts (default: 2000ms)
   void update(int textW, int displayW, unsigned long now,
               unsigned long speed_ms = 150, unsigned long pause_ms = 2000) {
     int maxScroll = textW - displayW;
@@ -35,13 +43,32 @@ struct MarqueeScroller {
   }
 };
 
+// UIColor framework: Provides consistent color definitions across different display types
+// Each display driver defines its own UIColor values based on its color capabilities
+// For monochrome displays: 0 = BLACK, 1 = WHITE
+// For color displays: 16-bit RGB values
+using ColorVal = uint16_t;
+
+class UIColor {
+public:
+  // UI element color definitions
+  // Each display driver implements these with appropriate values for its display
+  static ColorVal window_bkg;      // Background color for windows/panels
+  static ColorVal title_bkg;       // Background color for title bars
+  static ColorVal title_txt;       // Text color for titles
+  static ColorVal primary_txt;     // Primary text color (main content)
+  static ColorVal secondary_txt;   // Secondary text color (metadata, timestamps)
+  static ColorVal warning_txt;     // Warning/alert text color
+  static ColorVal popup_bkg;       // Background color for popups/dialogs
+  static ColorVal popup_txt;       // Text color for popups/dialogs
+  static ColorVal corp_blue;       // Corporate/brand color (blue)
+};
+
 class DisplayDriver {
   int _w, _h;
 protected:
   DisplayDriver(int w, int h) { _w = w; _h = h; }
 public:
-  enum Color { DARK=0, LIGHT, RED, GREEN, BLUE, YELLOW, ORANGE }; // on b/w screen, colors will be !=0 synonym of light
-
   int width() const { return _w; }
   int height() const { return _h; }
 
@@ -50,9 +77,9 @@ class DisplayDriver {
   virtual void turnOn() = 0;
   virtual void turnOff() = 0;
   virtual void clear() = 0;
-  virtual void startFrame(Color bkg = DARK) = 0;
+  virtual void startFrame(ColorVal bkg = UIColor::window_bkg) = 0;
   virtual void setTextSize(int sz) = 0;
-  virtual void setColor(Color c) = 0;
+  virtual void setColor(ColorVal c) = 0;
   virtual void setCursor(int x, int y) = 0;
   virtual void print(const char* str) = 0;
   virtual void printWordWrap(const char* str, int max_width) { print(str); }   // fallback to basic print() if no override
@@ -83,7 +110,7 @@ class DisplayDriver {
       if (c >= 32 && c <= 126) {
         dest[j++] = c;  // ASCII printable
       } else if (c >= 0x80) {
-        dest[j++] = '\xDB';  // CP437 full block ¦
+        dest[j++] = '\xDB';  // CP437 full block �
         while (src[i+1] && (src[i+1] & 0xC0) == 0x80) 
           i++;  // skip UTF-8 continuation bytes
       }

src/helpers/ui/SSD1306SPIDisplay.cpp

@@ -1,5 +1,16 @@
 #include "SSD1306SPIDisplay.h"
 
+// UIColor definitions for 64x48 OLED (black/white display)
+ColorVal UIColor::window_bkg = 0;       // BLACK
+ColorVal UIColor::title_bkg = 0;        // BLACK
+ColorVal UIColor::title_txt = 1;        // WHITE
+ColorVal UIColor::primary_txt = 1;      // WHITE
+ColorVal UIColor::secondary_txt = 1;    // WHITE
+ColorVal UIColor::warning_txt = 1;      // WHITE
+ColorVal UIColor::popup_bkg = 0;        // BLACK
+ColorVal UIColor::popup_txt = 1;        // WHITE
+ColorVal UIColor::corp_blue = 1;        // WHITE (B/W display)
+
 // Check if SPI is ready (set by radio_init in target.cpp)
 #if defined(P_LORA_SCLK)
   extern bool spi_initialized;
@@ -67,10 +78,10 @@ void SSD1306SPIDisplay::clear() {
   display.display();
 }
 
-void SSD1306SPIDisplay::startFrame(Color bkg) {
+void SSD1306SPIDisplay::startFrame(ColorVal bkg) {
   if (!lazyInit()) return;
   display.clearDisplay();  // TODO: apply 'bkg'
-  _color = SSD1306_WHITE;
+  _color = 1;  // WHITE
   display.setTextColor(_color);
   display.setFont(NULL);  // Default 6x8 font
   display.setTextSize(1);
@@ -82,8 +93,8 @@ void SSD1306SPIDisplay::setTextSize(int sz) {
   display.setTextSize(sz);
 }
 
-void SSD1306SPIDisplay::setColor(Color c) {
-  _color = (c != 0) ? SSD1306_WHITE : SSD1306_BLACK;
+void SSD1306SPIDisplay::setColor(ColorVal c) {
+  _color = (c != 0) ? 1 : 0;  // WHITE or BLACK
   display.setTextColor(_color);
 }
 

src/helpers/ui/SSD1306SPIDisplay.h

@@ -25,9 +25,9 @@ class SSD1306SPIDisplay : public DisplayDriver {
   void turnOn() override;
   void turnOff() override;
   void clear() override;
-  void startFrame(Color bkg = DARK) override;
+  void startFrame(ColorVal bkg = UIColor::window_bkg) override;
   void setTextSize(int sz) override;
-  void setColor(Color c) override;
+  void setColor(ColorVal c) override;
   void setCursor(int x, int y) override;
   void print(const char* str) override;
   void fillRect(int x, int y, int w, int h) override;

variants/m5stack_unit_c6l/README.md

@@ -0,0 +1,54 @@
+# M5Stack Unit C6L - MeshCore Variant
+
+## Overview
+
+Compact ESP32-C6 LoRa module with integrated SX1262 radio, 64x48 OLED display, and PI4IO I/O expander.
+
+## Hardware
+
+- **MCU:** ESP32-C6 (WiFi 6 + Bluetooth 5 LE)
+- **LoRa:** SX1262 (SPI)
+- **Display:** 64x48 SSD1306 OLED (SPI)
+- **I/O Expander:** PI4IO (I2C)
+- **LED:** NeoPixel (GPIO 2)
+- **Buzzer:** GPIO 11
+
+## Pin Configuration
+
+| Function | GPIO |
+|----------|------|
+| LoRa SCLK | 20 |
+| LoRa MISO | 22 |
+| LoRa MOSI | 21 |
+| LoRa NSS | 23 |
+| LoRa DIO1 | 7 |
+| Display CS | 6 |
+| Display DC | 18 |
+| Display RST | 15 |
+| I2C SDA | 10 |
+| I2C SCL | 8 |
+| NeoPixel | 2 |
+| Buzzer | 11 |
+| GPS RX | 4 |
+| GPS TX | 5 |
+
+## Firmware Environments
+
+| Environment | Interface | Use Case |
+|-------------|-----------|----------|
+| `m5stack_unit_c6l_companion_radio_usb` | USB Serial | Connect via USB |
+| `m5stack_unit_c6l_companion_radio_ble` | BLE | Connect via Bluetooth |
+| `m5stack_unit_c6l_repeater` | LoRa | Network extender |
+| `m5stack_unit_c6l_room_server` | LoRa | BBS server |
+| `m5stack_unit_c6l_kiss_modem` | USB Serial | KISS TNC |
+
+## Build
+
+```bash
+pio run -e m5stack_unit_c6l_companion_radio_usb
+```
+
+## Resources
+
+- [M5Stack Unit C6L Product Page](https://docs.m5stack.com/en/unit/Unit_C6L)
+- [MeshCore Documentation](https://docs.meshcore.io)

variants/m5stack_unit_c6l/companion/UITask.h

@@ -3,12 +3,13 @@
 #include <Arduino.h>
 #include <helpers/ui/DisplayDriver.h>
 #include <helpers/SensorManager.h>
+#include <helpers/MultiSerialInterface.h>
 #include "../../examples/companion_radio/NodePrefs.h"
 #include "../../examples/companion_radio/AbstractUITask.h"
 
 class UITask : public AbstractUITask {
 public:
-  UITask(mesh::MainBoard* board, BaseSerialInterface* serial)
+  UITask(mesh::MainBoard* board, MultiSerialInterface* serial)
     : AbstractUITask(board, serial), _display(NULL) {}
 
   void begin(DisplayDriver* display, SensorManager* sensors, NodePrefs* node_prefs);