Refactor power saving logic into display drivers and add ST7789 support

CMakeLists.txt

@@ -56,6 +56,7 @@ add_executable(basic1
     games/lua_bindings.cpp
     games/lua_game_loader.cpp
     lib/st7796/st7796.c 
+    lib/st7789/st7789.c 
     lib/ft6336u/ft6336u.c 
     lib/sd_card/sd_card.c 
     display/low_level_render.cpp 
@@ -102,6 +103,7 @@ target_include_directories(basic1 PRIVATE
     ${CMAKE_CURRENT_LIST_DIR}/lib/lua
     ${CMAKE_CURRENT_LIST_DIR}/lib/fatfs/source
     ${CMAKE_CURRENT_LIST_DIR}/lib/st7796
+    ${CMAKE_CURRENT_LIST_DIR}/lib/st7789
     ${CMAKE_CURRENT_LIST_DIR}/lib/ft6336u
     ${CMAKE_CURRENT_LIST_DIR}/lib/sd_card
     ${CMAKE_CURRENT_LIST_DIR}/display

basic1.cpp

@@ -160,56 +160,31 @@ struct GameConfig {
 #define DIM_TIMEOUT_MS (2 * 60 * 1000)   // 2 minutes to dim
 #define SLEEP_TIMEOUT_MS (10 * 60 * 1000) // 10 minutes to sleep
 #define DIM_CHECK_INTERVAL_MS 10000      // Check every 10 seconds
-#define DIM_BRIGHTNESS 5                 // Dimmed brightness level (0-100)
-#define NORMAL_BRIGHTNESS 100            // Normal brightness level (0-100)
 
 // Display dimming state
 static uint32_t last_interaction_time = 0;  // Last time user interacted
-static bool is_dimmed = false;              // Current dimming state
+static bool is_idle_2min_triggered = false; // Flag for 2min trigger
-static bool is_sleeping = false;            // Current sleep state
+static bool is_idle_10min_triggered = false; // Flag for 10min trigger
-static uint8_t saved_brightness = NORMAL_BRIGHTNESS;  // Brightness before dimming
 static volatile bool dim_check_flag = false;  // Flag set by timer to check dimming
 static LowLevelDisplay* global_display = nullptr;  // Global display pointer for timer callback
 
 /**
- * @brief Update last interaction time and restore display if dimmed
+ * @brief Update last interaction time and notify display driver
  * 
- * Call this whenever the user interacts with the device (touch, button press)
+ * Call this whenever the user interacts with the device (touch, button press).
- * to reset the dimming timer and restore display if it was dimmed/sleeping.
+ * The display driver handles specific wake/restore logic.
- * 
- * For TFT displays: Restores brightness level
- * For e-ink displays: Wakes display from sleep and refreshes screen
  * 
  * @param display Pointer to display interface
  */
 static inline void record_user_interaction(LowLevelDisplay* display) {
     last_interaction_time = to_ms_since_boot(get_absolute_time());
     
-    // If display was sleeping, wake it up
+    // Reset idle flags
-    if (is_sleeping) {
+    is_idle_2min_triggered = false;
-        if (display->get_type() == DISPLAY_TYPE_ST7796) {
+    is_idle_10min_triggered = false;
-            LowLevelDisplayST7796* tft = static_cast<LowLevelDisplayST7796*>(display);
+    
-            tft->wake();
+    // Notify display driver of interaction
-            tft->set_brightness(saved_brightness);
+    display->on_user_interaction();
-            printf("TFT display woken from sleep\n");
-        } else if (display->get_type() == DISPLAY_TYPE_EPAPER) {
-            printf("Waking e-paper display from sleep...\n");
-            LowLevelDisplayEPaper* epaper = static_cast<LowLevelDisplayEPaper*>(display);
-            epaper->init();
-            printf("E-paper display ready\n");
-        }
-        is_sleeping = false;
-        is_dimmed = false;
-    }
-    // If display was dimmed, restore brightness
-    else if (is_dimmed) {
-        if (display->get_type() == DISPLAY_TYPE_ST7796) {
-            LowLevelDisplayST7796* tft = static_cast<LowLevelDisplayST7796*>(display);
-            tft->set_brightness(saved_brightness);
-            printf("TFT display brightness restored\n");
-        }
-        is_dimmed = false;
-    }
 }
 
 /**
@@ -233,12 +208,10 @@ static int64_t dim_check_alarm_callback(alarm_id_t id, void *user_data) {
 }
 
 /**
- * @brief Check if display should be dimmed and apply dimming if needed
+ * @brief Check if idle thresholds have been met and notify display driver
  * 
- * Checks if the timeout has elapsed since last interaction and dims/sleeps
+ * Checks elapsed time since last interaction and calls the appropriate
- * the display based on its type:
+ * display driver methods (on_idle_2min or on_idle_10min).
- * - TFT displays (ST7796): Reduces brightness to minimum
- * - E-ink displays: Puts display to sleep mode (turns off)
  * 
  * @param display Pointer to display interface
  */
@@ -246,33 +219,16 @@ static inline void check_and_apply_dimming(LowLevelDisplay* display) {
     uint32_t current_time = to_ms_since_boot(get_absolute_time());
     uint32_t elapsed = current_time - last_interaction_time;
     
-    // Check for sleep timeout
+    // Check for 10 minute timeout (Sleep)
-    if (!is_sleeping && elapsed >= SLEEP_TIMEOUT_MS) {
+    if (!is_idle_10min_triggered && elapsed >= SLEEP_TIMEOUT_MS) {
-        if (display->get_type() == DISPLAY_TYPE_ST7796) {
+        display->on_idle_10min();
-            LowLevelDisplayST7796* tft = static_cast<LowLevelDisplayST7796*>(display);
+        is_idle_10min_triggered = true;
-            tft->sleep();
+        is_idle_2min_triggered = true; // Implicitly triggered
-            printf("TFT display put to sleep after %d minutes of inactivity\n", 
-                   SLEEP_TIMEOUT_MS / 60000);
-        } else if (display->get_type() == DISPLAY_TYPE_EPAPER) {
-            LowLevelDisplayEPaper* epaper = static_cast<LowLevelDisplayEPaper*>(display);
-            epaper->sleep();
-            printf("E-paper display put to sleep after %d minutes of inactivity\n", 
-                   SLEEP_TIMEOUT_MS / 60000);
-        }
-        is_sleeping = true;
-        is_dimmed = true; // Sleep implies dimmed state
     }
-    // Check for dim timeout
+    // Check for 2 minute timeout (Dim)
-    else if (!is_dimmed && !is_sleeping && elapsed >= DIM_TIMEOUT_MS) {
+    else if (!is_idle_2min_triggered && elapsed >= DIM_TIMEOUT_MS) {
-        if (display->get_type() == DISPLAY_TYPE_ST7796) {
+        display->on_idle_2min();
-            saved_brightness = display->get_brightness();
+        is_idle_2min_triggered = true;
-            LowLevelDisplayST7796* tft = static_cast<LowLevelDisplayST7796*>(display);
-            tft->set_brightness(DIM_BRIGHTNESS);
-            printf("TFT display dimmed after %d minutes of inactivity\n", 
-                   DIM_TIMEOUT_MS / 60000);
-        }
-        // E-paper doesn't support dimming, so we skip it until sleep timeout
-        is_dimmed = true;
     }
 }
 
@@ -582,11 +538,10 @@ int main()
     add_alarm_in_ms(DIM_CHECK_INTERVAL_MS, dim_check_alarm_callback, nullptr, true);
     
     if (display->get_type() == DISPLAY_TYPE_ST7796) {
-        printf("Power saving enabled: Dim after %d min, Sleep after %d min\n", 
+        printf("Power saving: Dim at %d min, Sleep at %d min\n", 
                DIM_TIMEOUT_MS / 60000, SLEEP_TIMEOUT_MS / 60000);
-    } else if (display->get_type() == DISPLAY_TYPE_EPAPER) {
+    } else {
-        printf("Auto-sleep enabled: E-paper will sleep after %d minutes of inactivity\n", 
+        printf("Power saving: Sleep at %d min\n", SLEEP_TIMEOUT_MS / 60000);
-               SLEEP_TIMEOUT_MS / 60000);
     }
     printf("Dimming check timer set to %d seconds\n", DIM_CHECK_INTERVAL_MS / 1000);
     

display/low_level_display.h

@@ -40,6 +40,11 @@ public:
     // Optional: Orientation control (not commonly needed for bitmap displays)
     virtual void set_rotation(uint8_t rotation) { (void)rotation; }
     
+    // Power saving hooks
+    virtual void on_idle_2min() {}
+    virtual void on_idle_10min() {}
+    virtual void on_user_interaction() {}
+
     // Factory method - creates display based on type, using board_config.h for pins
     static LowLevelDisplay* create(DisplayType type, int width, int height);
 };

display/low_level_display_epaper.cpp

@@ -141,3 +141,24 @@ void LowLevelDisplayEPaper::sleep() {
     printf("Putting e-paper display to sleep...\n");
     EPD_4IN2_V2_Sleep();
 }
+
+void LowLevelDisplayEPaper::on_idle_2min() {
+    // E-paper doesn't dim
+}
+
+void LowLevelDisplayEPaper::on_idle_10min() {
+    if (!is_sleeping) {
+        sleep();
+        is_sleeping = true;
+        printf("E-Paper: Entered sleep mode\n");
+    }
+}
+
+void LowLevelDisplayEPaper::on_user_interaction() {
+    if (is_sleeping) {
+        printf("E-Paper: Waking from sleep...\n");
+        init(); // Re-initialize to wake up
+        is_sleeping = false;
+        printf("E-Paper: Ready\n");
+    }
+}

display/low_level_display_epaper.h

@@ -44,6 +44,14 @@ public:
     void clear_display();  // Full clear with refresh
     void full_refresh();   // Force full screen refresh (slower but removes ghosting)
     void sleep();          // Put display in low power mode
+
+    // Power saving hooks
+    void on_idle_2min() override;
+    void on_idle_10min() override;
+    void on_user_interaction() override;
+
+private:
+    bool is_sleeping = false;
 };
 
 #endif // LOW_LEVEL_DISPLAY_EPAPER_H

display/low_level_display_st7789.cpp

@@ -69,11 +69,51 @@ void LowLevelDisplayST7789::refresh() {
 }
 
 void LowLevelDisplayST7789::set_backlight(bool on) {
-    // TODO: Implement
+    set_brightness(on ? 100 : 0);
-    (void)on;
+}
+
+void LowLevelDisplayST7789::set_brightness(uint8_t brightness) {
+    st7789_set_brightness(brightness);
+}
+
+uint8_t LowLevelDisplayST7789::get_brightness() const {
+    return st7789_get_brightness();
 }
 
 void LowLevelDisplayST7789::set_rotation(uint8_t rotation) {
     // TODO: Implement
     (void)rotation;
 }
+
+void LowLevelDisplayST7789::on_idle_2min() {
+    if (!is_dimmed && !is_sleeping) {
+        saved_brightness = get_brightness();
+        set_brightness(5); // Dim to 5%
+        is_dimmed = true;
+        printf("ST7789: Dimmed to 5%%\n");
+    }
+}
+
+void LowLevelDisplayST7789::on_idle_10min() {
+    if (!is_sleeping) {
+        st7789_sleep();
+        is_sleeping = true;
+        is_dimmed = true; // Sleep implies dimmed
+        printf("ST7789: Entered sleep mode\n");
+    }
+}
+
+void LowLevelDisplayST7789::on_user_interaction() {
+    if (is_sleeping) {
+        st7789_wake();
+        // Restore brightness if we have a saved value, or default to 100
+        set_brightness(saved_brightness > 0 ? saved_brightness : 100);
+        is_sleeping = false;
+        is_dimmed = false;
+        printf("ST7789: Woke from sleep\n");
+    } else if (is_dimmed) {
+        set_brightness(saved_brightness > 0 ? saved_brightness : 100);
+        is_dimmed = false;
+        printf("ST7789: Restored brightness\n");
+    }
+}

display/low_level_display_st7789.h

@@ -2,17 +2,7 @@
 #define LOW_LEVEL_DISPLAY_ST7789_H
 
 #include "low_level_display.h"
-
+#include "st7789.h"
-// ST7789 configuration structure (similar to ST7796)
-struct st7789_config {
-    void* spi;           // SPI instance
-    int gpio_din;        // MOSI pin
-    int gpio_clk;        // Clock pin
-    int gpio_cs;         // Chip select pin
-    int gpio_dc;         // Data/Command pin
-    int gpio_rst;        // Reset pin
-    int gpio_bl;         // Backlight pin
-};
 
 class LowLevelDisplayST7789 : public LowLevelDisplay {
 private:
@@ -42,8 +32,22 @@ public:
     // Backlight control
     void set_backlight(bool on) override;
     
+    // Brightness control
+    void set_brightness(uint8_t brightness) override;
+    uint8_t get_brightness() const override;
+
     // Orientation control
     void set_rotation(uint8_t rotation) override;
+
+    // Power saving hooks
+    void on_idle_2min() override;
+    void on_idle_10min() override;
+    void on_user_interaction() override;
+
+private:
+    uint8_t saved_brightness = 100;
+    bool is_dimmed = false;
+    bool is_sleeping = false;
 };
 
 #endif // LOW_LEVEL_DISPLAY_ST7789_H

display/low_level_display_st7796.cpp

@@ -94,3 +94,36 @@ void LowLevelDisplayST7796::set_rotation(uint8_t rotation) {
     // TODO: Add MADCTL register manipulation for rotation
     (void)rotation;
 }
+
+void LowLevelDisplayST7796::on_idle_2min() {
+    if (!is_dimmed && !is_sleeping) {
+        saved_brightness = get_brightness();
+        set_brightness(5); // Dim to 5%
+        is_dimmed = true;
+        printf("TFT: Dimmed to 5%%\n");
+    }
+}
+
+void LowLevelDisplayST7796::on_idle_10min() {
+    if (!is_sleeping) {
+        sleep();
+        is_sleeping = true;
+        is_dimmed = true; // Sleep implies dimmed
+        printf("TFT: Entered sleep mode\n");
+    }
+}
+
+void LowLevelDisplayST7796::on_user_interaction() {
+    if (is_sleeping) {
+        wake();
+        // Restore brightness if we have a saved value, or default to 100
+        set_brightness(saved_brightness > 0 ? saved_brightness : 100);
+        is_sleeping = false;
+        is_dimmed = false;
+        printf("TFT: Woke from sleep\n");
+    } else if (is_dimmed) {
+        set_brightness(saved_brightness > 0 ? saved_brightness : 100);
+        is_dimmed = false;
+        printf("TFT: Restored brightness\n");
+    }
+}

display/low_level_display_st7796.h

@@ -47,6 +47,16 @@ public:
     // Color inversion control
     void set_invert_color(bool inv) { invert_color = inv; }
     bool get_invert_color() const { return invert_color; }
+
+    // Power saving hooks
+    void on_idle_2min() override;
+    void on_idle_10min() override;
+    void on_user_interaction() override;
+
+private:
+    uint8_t saved_brightness = 100;
+    bool is_dimmed = false;
+    bool is_sleeping = false;
 };
 
 #endif // LOW_LEVEL_DISPLAY_ST7796_H

lib/st7789/st7789.c

@@ -12,6 +12,7 @@
 
 #include "hardware/gpio.h"
 #include "hardware/spi.h"
+#include "hardware/pwm.h"
 #include "pico/binary_info.h"
 #include "pico/stdlib.h"
 
@@ -60,6 +61,12 @@ static uint16_t height;
 static uint16_t x_offset;
 static uint16_t y_offset;
 
+// Backlight control
+static uint pwm_slice;
+static uint pwm_channel;
+static uint8_t current_brightness = 100;
+static bool pwm_initialized = false;
+
 static inline void cs_select() {
     if (config->gpio_cs >= 0) {
         asm volatile("nop \n nop \n nop");
@@ -173,10 +180,19 @@ void st7789_init(const struct st7789_config *c, uint16_t w, uint16_t h) {
     gpio_init(config->gpio_rst);
     gpio_set_dir(config->gpio_rst, GPIO_OUT);
 
-    // Initialize backlight pin
+    // Initialize backlight pin with PWM
-    gpio_init(config->gpio_bl);
+    if (config->gpio_bl >= 0) {
-    gpio_set_dir(config->gpio_bl, GPIO_OUT);
+        gpio_set_function(config->gpio_bl, GPIO_FUNC_PWM);
-    gpio_put(config->gpio_bl, 1); // Turn on backlight
+        pwm_slice = pwm_gpio_to_slice_num(config->gpio_bl);
+        pwm_channel = pwm_gpio_to_channel(config->gpio_bl);
+        
+        // Set PWM frequency to ~1kHz
+        pwm_set_wrap(pwm_slice, 65535);
+        pwm_set_chan_level(pwm_slice, pwm_channel, 65535); // 100% duty cycle
+        pwm_set_enabled(pwm_slice, true);
+        
+        pwm_initialized = true;
+    }
 
     // Reset display
     reset_pulse();
@@ -403,3 +419,48 @@ void st7789_draw_line(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1, uint16
         }
     }
 }
+
+void st7789_set_brightness(uint8_t brightness) {
+    if (!pwm_initialized || config->gpio_bl < 0) return;
+    
+    // Clamp brightness
+    if (brightness > 100) brightness = 100;
+    
+    current_brightness = brightness;
+    
+    // Convert 0-100 to 0-65535
+    uint16_t level = (uint16_t)((brightness * 65535) / 100);
+    pwm_set_chan_level(pwm_slice, pwm_channel, level);
+}
+
+uint8_t st7789_get_brightness(void) {
+    return current_brightness;
+}
+
+void st7789_sleep(void) {
+    // Turn off backlight
+    if (pwm_initialized && config->gpio_bl >= 0) {
+        pwm_set_chan_level(pwm_slice, pwm_channel, 0);
+    }
+    
+    // Display off
+    write_command(ST7789_DISPOFF);
+    sleep_ms(10);
+    
+    // Sleep in
+    write_command(ST7789_SLPIN);
+    sleep_ms(120);
+}
+
+void st7789_wake(void) {
+    // Sleep out
+    write_command(ST7789_SLPOUT);
+    sleep_ms(120);
+    
+    // Display on
+    write_command(ST7789_DISPON);
+    sleep_ms(10);
+    
+    // Restore brightness
+    st7789_set_brightness(current_brightness);
+}

lib/st7789/st7789.h

@@ -38,6 +38,11 @@ void st7789_draw_circle(uint16_t x0, uint16_t y0, uint16_t r, uint16_t color);
 void st7789_fill_circle(uint16_t x0, uint16_t y0, uint16_t r, uint16_t color);
 void st7789_draw_line(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1, uint16_t color);
 
+void st7789_sleep(void);
+void st7789_wake(void);
+void st7789_set_brightness(uint8_t brightness);
+uint8_t st7789_get_brightness(void);
+
 #ifdef __cplusplus
 }
 #endif