rgb_led.hpp

Go to the documentation of this file.

/**
 * @file rgb_led.hpp
 * @brief RGB LED component — state holder with 8-bit color depth
 * @ingroup components
 *
 * RgbLed stores per-channel duty cycle (0-255). The output backend
 * (SoftPwm for BCM, or GPIO for bang-bang) reads state via state().
 *
 * The 3-bit Color enum provides the 8 RGB cube corners at full brightness.
 * For intermediate colors, use set_rgb().
 *
 * Usage:
 *   sbl::components::display::RgbLed led;
 *   led.set_color(sbl::components::display::Color::Red);
 *   led.set_rgb(128, 0, 255);  // purple at half red
 *   auto s = led.state();      // {128, 0, 255}
 */
 
#ifndef SBL_COMPONENTS_DISPLAY_RGB_LED_HPP_
#define SBL_COMPONENTS_DISPLAY_RGB_LED_HPP_
 
#include <cstdint>
 
namespace sbl {
namespace components {
namespace display {
 
/**
 * @brief 3-bit color enum — all 8 RGB combinations
 *
 * Bit layout: [R:G:B] where bit 2=R, bit 1=G, bit 0=B.
 * Maps to full brightness (255) per active channel.
 */
enum class Color : uint8_t {
    Off     = 0,  // 000
    Blue    = 1,  // 001
    Green   = 2,  // 010
    Cyan    = 3,  // 011
    Red     = 4,  // 100
    Magenta = 5,  // 101
    Yellow  = 6,  // 110
    White   = 7,  // 111
};
 
struct RgbLedState {
    uint8_t r;
    uint8_t g;
    uint8_t b;
};
 
/**
 * @brief RGB LED state holder with 8-bit per-channel duty cycle
 *
 * @note All public methods are ISR-safe — pure state machine with no hardware I/O.
 */
class RgbLed {
public:
    RgbLed() : r_(0), g_(0), b_(0) {}
 
    /** @brief Set per-channel duty cycle (0-255) */
    void set_rgb(uint8_t r, uint8_t g, uint8_t b) {
        r_ = r;
        g_ = g;
        b_ = b;
    }
 
    /** @brief Set from Color enum (full brightness per active channel) */
    void set_color(Color color) {
        uint8_t c = static_cast<uint8_t>(color);
        r_ = (c & 4) ? 255 : 0;
        g_ = (c & 2) ? 255 : 0;
        b_ = (c & 1) ? 255 : 0;
    }
 
    /** @brief Turn off all channels */
    void off() {
        r_ = 0;
        g_ = 0;
        b_ = 0;
    }
 
    /** @brief Current state */
    RgbLedState state() const { return {r_, g_, b_}; }
 
private:
    uint8_t r_;
    uint8_t g_;
    uint8_t b_;
};
 
} // namespace display
} // namespace components
} // namespace sbl
 
#endif // SBL_COMPONENTS_DISPLAY_RGB_LED_HPP_