global edp

src/epd_utils.py

@@ -1,49 +1,36 @@
 import logging
-from contextlib import contextmanager
-from sys import path
 
 from PIL import Image
 from flask import Response, jsonify
 from filelock import Timeout as FileLockTimeout, FileLock
 
 from models import Mode
 
-path.append('lib')
-# noinspection PyUnresolvedReferences
-from waveshare_epd import epd4in26
 
-@contextmanager
-def get_epd_lock():
-    lock = FileLock('epd.lock', timeout=10)
-    with lock.acquire():
-        yield epd4in26.EPD()
+def display_clear(epd):
+    epd.init()
+    epd.Clear()
+    epd.sleep()
 
-def display_clear():
-    with get_epd_lock() as epd:
+def display_img(epd, image: Image, mode: Mode):
+    if mode == Mode.FOUR_GRAY:
+        epd.init_4GRAY()
+        epd.display_4Gray(epd.getbuffer_4Gray(image))
+    if mode == Mode.PARTIAL:
         epd.init()
-        epd.Clear()
-        epd.sleep()
-
-def display_img(image: Image, mode: Mode):
-    with get_epd_lock() as epd:
-        if mode == Mode.FOUR_GRAY:
-            epd.init_4GRAY()
-            epd.display_4Gray(epd.getbuffer_4Gray(image))
-        if mode == Mode.PARTIAL:
-            epd.init()
-            epd.display_Partial(epd.getbuffer(image))
-        else:
-            epd.init_Fast()
-            epd.display_Fast(epd.getbuffer(image))
-        epd.sleep()
+        epd.display_Partial(epd.getbuffer(image))
+    else:
+        epd.init_Fast()
+        epd.display_Fast(epd.getbuffer(image))
+    epd.sleep()
 
 def handle_epd_error(e: Exception) -> tuple[Response, int]:
     if isinstance(e, IOError):
         logging.error(f'IOError on display write: {str(e)}')
         return jsonify(message='Unexpected error'), 500
     elif isinstance(e, KeyboardInterrupt):
         logging.info('Display write interrupted due to KeyboardInterrupt')
-        epd4in26.epdconfig.module_exit(cleanup=True)
+        #epd4in26.epdconfig.module_exit(cleanup=True)
         return jsonify(message='Cancelled'), 500
     elif isinstance(e, FileLockTimeout):
         logging.info('Could not obtain device lock')

src/server.py

@@ -8,13 +8,20 @@
 from models import Resolution, Rotation, Resize, BackgroundColour, Mode
 
 from img_utils import resize_img, image_changed
-from epd_utils import get_epd_lock, handle_epd_error, display_clear, display_img
+from epd_utils import handle_epd_error, display_clear, display_img
+
+from sys import path
+path.append('lib')
+# noinspection PyUnresolvedReferences
+from waveshare_epd import epd4in26
 
 IMG_PATH = 'img.png'
 DISPLAY_RESOLUTION = Resolution(800, 480)
 
 logging.basicConfig(level=logging.DEBUG)
 
+epd = epd4in26.EPD()
+
 app = Flask(__name__)
 
 
@@ -72,7 +79,7 @@ def show_image() -> tuple[Response, int]:
 
     if update_image:
         try:
-            display_img(image_to_display, mode)
+            display_img(epd, image_to_display, mode)
             image_to_display.save(IMG_PATH)
         except Exception as e:
             return handle_epd_error(e)
@@ -83,7 +90,7 @@ def show_image() -> tuple[Response, int]:
 @app.route("/", methods=['DELETE'])
 def clear_image():
     try:
-        display_clear()
+        display_clear(epd)
         Image.new('1', DISPLAY_RESOLUTION, 255).save(IMG_PATH)
         return jsonify(message='Success'), 200
     except Exception as e: