screen auto off in 30s

README.md

@@ -0,0 +1,61 @@
+# eInk API for Raspberry Pi Pico
+
+This firmware drives a Waveshare 4.2" e-Paper display from a Raspberry Pi Pico / Pico W. It launches the e-paper driver on core 1 while core 0 acts as a simple serial command processor, giving you an interactive API for drawing primitives, text, and editor-mode logs over USB.
+
+## Features
+
+- Lightweight C implementation built on the official Pico SDK and Waveshare e-Paper drivers.
+- Core 1 renders directly to a framebuffer and updates the display with both full and partial refreshes.
+- Serial command queue exposes operations such as clearing, drawing geometry, writing text, and entering an editor mode.
+- Automatic display shutdown after 30 seconds of inactivity to preserve the panel.
+
+## Requirements
+
+- Raspberry Pi Pico or Pico W (project sets `PICO_BOARD` to `pico_w`).
+- Waveshare 4.2" e-Paper V2 display, wired to SPI + compatible GPIOs defined in `DEV_Config.h`.
+- Pico SDK (2.2.0) installed and available via `PICO_SDK_PATH`.
+- `cmake`, `ninja`, and `picotool` (or the Pico toolchain) for flashing.
+
+## Building
+
+```sh
+# configure the build
+cmake -S . -B build
+
+# build the UF2 image
+cmake --build build
+```
+
+After building, flash the firmware to your Pico (e.g. by copying `build/eink_api.uf2` to the Pico's mass storage device or using `picotool load build/eink_api.uf2`).
+
+## Usage
+
+1. Open a serial terminal (115200 baud) over the Pico's USB CDC interface.
+2. Type commands followed by `Enter`. The firmware echoes the command buffer and executes the operation on core 1.
+3. Most commands require the display to be initialized (`init`). The device automatically turns off the screen after ~30 seconds of inactivity, so send another command to revive it.
+4. If `editor` mode is enabled, keystrokes are batched and rendered directly on the display until inactivity ends the mode.
+
+### Supported Commands
+
+| Command | Description |
+| --- | --- |
+| `init` | Initializes the e-Paper panel and allocates the framebuffer. |
+| `clear` | Clears the current framebuffer to white (requires display on). |
+| `display` | Pushes the framebuffer to the panel (requires display on). |
+| `draw_test` | Draws a hard-coded Waveshare demo pattern. |
+| `draw_text x y text` | Writes `text` at `(x,y)` using the current font. |
+| `draw_point x y` | Draws a black point at the given coordinates. |
+| `draw_line x1 y1 x2 y2` | Draws a black line between two points. |
+| `draw_rectangle x1 y1 x2 y2` | Draws an empty rectangle. |
+| `draw_circle x y r` | Draws an empty circle with radius `r`. |
+| `draw_num x y num` | Draws `num` using the default numeric font. |
+| `set_pixel x y color` | Sets a single pixel to `color` (0=white, 1=black). |
+| `close` | Sends the panel to deep sleep and frees the framebuffer. |
+| `editor` | Enables editor mode; text typed is rendered live on-screen until inactivity. |
+
+## Notes
+
+- The project imports the Waveshare e-Paper libraries from `Pico_ePaper_Code/c/lib/*` for configuration, fonts, GUI primitives, and the panel driver.
+- USB serial I/O is enabled (`pico_enable_stdio_usb`), while UART stdio is disabled to avoid conflicts (`pico_enable_stdio_uart` set to `0`).
+- The firmware allocates the framebuffer via `malloc` and frees it when the display goes to sleep; avoid running out of heap on severely constrained Pico builds.
+- Editor-mode inactivity is 10 seconds before automatically exiting back to command mode.

eink_api.c

@@ -21,6 +21,7 @@ void process_command(char *cmd);
 void core1_entry();
 
 bool screen_on = false;
+uint32_t screen_last_ts = 0;
 
 int epaper_init()
 {
@@ -47,7 +48,7 @@ int epaper_init()
 }
 
 bool editor_mode = false;
-int editor_last_ts = 0;
+uint32_t editor_last_ts = 0;
 char screen_log[2000];
 int screen_log_i = 0;
 sFONT *current_font = &Font16;
@@ -211,6 +212,8 @@ void core1_entry() {
             if(!screen_on){
                 epaper_init();
             }
+            absolute_time_t time = get_absolute_time();
+            screen_last_ts = to_ms_since_boot(time);
             if(editor_mode){
                 bool overflow = false;
                 Paint_Clear(WHITE);
@@ -243,6 +246,14 @@ void core1_entry() {
             }
             
         }
+        if(screen_on){
+            absolute_time_t time = get_absolute_time();
+            uint32_t ms = to_ms_since_boot(time);
+            if(screen_last_ts + 30000 < ms){
+                printf("Turning off screen due to inactivity (30s)");
+                epaper_close();
+            }
+        }
     }
 }