allow switching screens with input buttons

camp_small.py

 from manager import Manager
 import util
 
-url = "http://ubabot.frubar.net"
+#url = "http://ubabot.frubar.net"
+url = "http://www.xythobuz.de"
 
 # Need to import InputWrapper before initializing RGB Matrix on Pi
 i = InputWrapper()
 
 # UbaBot is online
 success = Manager(t)
-success.add(ImageScreen(t, "drinka.gif", 0.2, 2, 20.0))
+success.add(ImageScreen(t, "drinka.gif", 0.2, 2, 20.0, (0, 0, 0)))
 success.add(Solid(t, 1.0))
 success.add(QRScreen(t, url, 30.0, "Drinks:", "tom-thumb", (255, 255, 255), (0, 0, 0)))
 success.add(Solid(t, 1.0))
 # UbaBot is offline
 fail = Manager(t)
 fail.add(ImageScreen(t, "attention.gif", 0.2, 2, 20.0, (0, 0, 0)))
+fail.add(Solid(t, 1.0))
 fail.add(ScrollText(t, "The UbaBot Cocktail machine is currently closed. Please come back later for more drinks!", "lemon", 2, 75, camp_pink))
 fail.add(Solid(t, 1.0))
 fail.add(GameOfLife(t, 20, (0, 255, 0), (0, 0, 0), None, 2.0))
 d.fail(fail)
 
 # Main "Menu"
-m = Manager(t)
+m = Manager(t, i)
 m.add(ScrollText(t, "#CCCAMP23", "lemon", 1, 75, camp_green))
 m.add(Solid(t, 1.0))
 m.add(ImageScreen(t, "Favicon.png", 0, 1, 10.0))

gamepad.py

                         self.keys["x"] = v
                     elif (event.code == ecodes.KEY_ENTER) or (event.code == ecodes.BTN_Y) or (event.code == ecodes.BTN_TOP):
                         self.keys["y"] = v
-                    elif event.code == ecodes.BTN_PINKIE:
+                    elif (event.code == ecodes.BTN_PINKIE) or (event.code == ecodes.KEY_D):
                         self.keys["r"] = v
-                    elif event.code == ecodes.BTN_TOP2:
+                    elif (event.code == ecodes.BTN_TOP2) or (event.code == ecodes.KEY_A):
                         self.keys["l"] = v
                     elif event.code == ecodes.BTN_BASE4:
                         self.keys["start"] = v

image.py

 from PIL import Image
 import time
 import os
-import util
+
+# GIF images contain Palletes for each frame.
+# These can be different between frames.
+# So the library is converting them to RGB.
+# This means we can not replace the background easily
+# for all but the first frame in animations.
+# This setting changes that to keep the same palette, as long as possible.
+# This works with some GIFs, but not all of them.
+from PIL import GifImagePlugin
+GifImagePlugin.LOADING_STRATEGY = GifImagePlugin.LoadingStrategy.RGB_AFTER_DIFFERENT_PALETTE_ONLY
 
 class ImageScreen:
-    def __init__(self, g, p, t = 0.2, i = 1, to = 10.0, bg = None):
+    def __init__(self, g, p, t = 0.2, i = 1, to = 5.0, bg = None):
         self.gui = g
         self.time = t
         self.iterations = i
 
             # keep the aspect ratio and fit within visible area
             ratio = self.image.width / self.image.height
-            width = self.gui.width
-            height = self.gui.height
-            if width < height:
-                width = self.gui.width
-                height = int(width / ratio)
-            else:
+            max_width = int(ratio * self.gui.height)
+            max_height = int(self.gui.width / ratio)
+            if (max_height >= self.gui.height) or (((self.gui.width - max_width) < (self.gui.height - max_height)) and ((self.gui.width - max_width) >= 0)):
+                width = max_width
                 height = self.gui.height
-                width = int(ratio * height)
+            else:
+                width = self.gui.width
+                height = max_height
 
             # resize
             self.image = self.image.resize((width, height),
     def finished(self):
         if self.done >= self.iterations:
             return True
-        return (time.time() - self.start) >= self.timeout
+
+        # only apply timeout for static images
+        if self.image.is_animated:
+            return False
+        else:
+            return (time.time() - self.start) >= self.timeout
 
     def draw(self):
         if self.image.is_animated:
                     self.gui.set_pixel(x + self.xOff, y + self.yOff, v)
 
 if __name__ == "__main__":
+    import sys
+
     import util
     t = util.getTarget()
 
         if filename != "Favicon.png":
             continue
 
-        # dump generated image to console, for embedding in Pico script
-        print()
-        print("Dumping image to img_tmp.py")
-        with open("img_tmp.py", "w") as f:
-            f.write("# Image \"" + filename + "\"" + os.linesep)
-            f.write("# size:" + str(d.image.width) + "x" + str(d.image.height) + os.linesep)
-            f.write("img_data = [" + os.linesep)
-            for y in range(0, d.image.height):
-                f.write("    [" + os.linesep)
-                for x in range(0, d.image.width):
-                    s = str(d.image.getpixel((x, y)))
-                    f.write("        " + s + "," + os.linesep)
-                f.write("    ]," + os.linesep)
-            f.write("]" + os.linesep)
-        print()
+        try:
+            # dump generated image to console, for embedding in Pico script
+            print()
+            print("Dumping image to img_tmp.py")
+            with open("img_tmp.py", "w") as f:
+                f.write("# Image \"" + filename + "\"" + os.linesep)
+                f.write("# size:" + str(d.image.width) + "x" + str(d.image.height) + os.linesep)
+                f.write("img_data = [" + os.linesep)
+                for y in range(0, d.image.height):
+                    f.write("    [" + os.linesep)
+                    for x in range(0, d.image.width):
+                        s = str(d.image.getpixel((x, y)))
+                        f.write("        " + s + "," + os.linesep)
+                    f.write("    ]," + os.linesep)
+                f.write("]" + os.linesep)
+            print()
+        except Exception as e:
+            print()
+            if hasattr(sys, "print_exception"):
+                sys.print_exception(e)
+            else:
+                print(e)
+                print()
 
     m.restart()
     t.loop(m.draw)

img_tmp.py

 # Image "Favicon.png"
-# size:32x32
+# size:32x24
 img_data = [
     [
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (73, 21, 57),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (63, 18, 49),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (238, 68, 186),
-        (0, 0, 0),
-    ],
-    [
-        (0, 0, 0),
-        (0, 0, 0),
-        (44, 13, 35),
-        (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
+        (3, 1, 2),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
-        (66, 19, 51),
+        (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
-        (213, 61, 166),
+        (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
     ],
     [
         (0, 0, 0),
-        (245, 70, 191),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
+        (249, 71, 194),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (234, 67, 183),
+        (21, 6, 16),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (0, 0, 0),
-        (251, 72, 196),
+        (53, 15, 42),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
+        (177, 51, 138),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (249, 71, 194),
-        (251, 72, 196),
-        (251, 72, 196),
-        (4, 1, 3),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
         (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-    ],
-    [
-        (0, 0, 0),
-        (251, 72, 196),
-        (251, 72, 196),
-        (126, 36, 98),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
+        (183, 53, 143),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
+        (71, 20, 55),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
-        (251, 72, 196),
-        (0, 0, 0),
+        (129, 37, 101),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
     ],
     [
-        (84, 24, 65),
+        (97, 28, 76),
         (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (251, 72, 196),
+        (237, 68, 185),
         (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
     ],
     [
-        (110, 32, 86),
+        (86, 25, 67),
         (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (189, 54, 148),
-        (251, 72, 196),
-        (251, 72, 196),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (199, 57, 155),
-        (251, 72, 196),
+        (230, 66, 180),
         (251, 72, 196),
         (251, 72, 196),
-        (4, 1, 3),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-    ],
-    [
-        (40, 12, 32),
         (251, 72, 196),
         (251, 72, 196),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (181, 52, 141),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (21, 6, 16),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
     ],
     [
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (198, 57, 154),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
-        (21, 6, 16),
+        (251, 72, 196),
+        (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (251, 72, 196),
         (251, 72, 196),
-        (249, 71, 194),
+        (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
+        (179, 51, 140),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
-        (251, 72, 196),
-        (0, 0, 0),
+        (50, 14, 39),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (248, 71, 194),
-        (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-    ],
-    [
-        (0, 0, 0),
-        (63, 18, 49),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (10, 3, 8),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (35, 10, 28),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (189, 54, 148),
         (251, 72, 196),
         (251, 72, 196),
-        (189, 54, 148),
-        (189, 54, 148),
-        (211, 60, 164),
         (251, 72, 196),
         (251, 72, 196),
-        (251, 72, 196),
-        (71, 20, 55),
-    ],
-    [
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (35, 10, 28),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (0, 0, 0),
+        (240, 69, 188),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (246, 71, 192),
+        (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (0, 0, 0),
+        (208, 60, 162),
+        (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
-        (213, 61, 166),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (0, 0, 0),
+        (10, 3, 8),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-        (0, 0, 0),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (15, 4, 12),
-        (171, 49, 134),
-        (251, 72, 196),
-        (251, 72, 196),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (189, 54, 148),
-        (251, 72, 196),
-        (251, 72, 196),
-        (126, 36, 98),
-        (126, 36, 98),
         (138, 40, 108),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
-        (79, 23, 61),
-    ],
-    [
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (251, 72, 196),
     [
         (0, 0, 0),
         (0, 0, 0),
-        (69, 20, 54),
+        (242, 69, 189),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (251, 72, 196),
         (251, 72, 196),
-        (60, 17, 47),
+        (164, 47, 128),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
-        (14, 4, 11),
-        (0, 0, 0),
-    ],
-    [
-        (0, 0, 0),
-        (0, 0, 0),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (189, 54, 148),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (251, 72, 196),
-        (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
     ],
     [
         (0, 0, 0),
-        (251, 72, 196),
+        (198, 57, 154),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
     ],
     [
-        (118, 34, 92),
+        (0, 0, 0),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
         (251, 72, 196),
-        (190, 54, 148),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (189, 54, 148),
-        (251, 72, 196),
         (251, 72, 196),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
         (0, 0, 0),
-    ],
-    [
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
-        (0, 0, 0),
         (189, 54, 148),
         (251, 72, 196),
         (251, 72, 196),

manager.py

 import time
 
 class Manager:
-    def __init__(self, g):
+    def __init__(self, g, i = None, ss = 2):
         self.gui = g
+        self.input = i
+        self.step_size = ss
         self.screens = []
         self.restart()
 
         self.index = 0
         self.done = False
         self.lastTime = time.time()
+        self.old_keys = {
+            "l": False,
+            "r": False,
+        }
+
+        #print("Manager ", len(self.screens), " reset to ", self.index)
+
         if len(self.screens) > 0:
             self.screens[0][0].restart()
 
         v = (s, d)
         self.screens.append(v)
 
+    def buttons(self):
+        keys = self.input.get()
+
+        if keys["l"] and (not self.old_keys["l"]):
+            c = self.screens[self.index][0]
+            if hasattr(c, "switch_to") and hasattr(c, "child_count"):
+                if c.child_count(-1):
+                    self.switch_to(-1, False)
+                else:
+                    c.switch_to(-1, False)
+            else:
+                self.switch_to(-1, False)
+        elif keys["r"] and (not self.old_keys["r"]):
+            c = self.screens[self.index][0]
+            if hasattr(c, "switch_to") and hasattr(c, "child_count"):
+                if c.child_count(1):
+                    self.switch_to(1, False)
+                else:
+                    c.switch_to(1, False)
+            else:
+                self.switch_to(1, False)
+
+        self.old_keys = keys.copy()
+
+    def child_count(self, i):
+        if i > 0:
+            index = int(self.index / self.step_size)
+            l = int(len(self.screens) / self.step_size)
+            return index >= (l - 1)
+        else:
+            return self.index <= 0
+
+    def switch_to(self, i, update_flag):
+        self.lastTime = time.time()
+        self.index = int((int(self.index / self.step_size) + i) * self.step_size) % len(self.screens)
+
+        #print("Manager ", len(self.screens), " switch to ", self.index, update_flag)
+
+        if update_flag:
+            self.done = (self.index == 0)
+
+        self.screens[self.index][0].restart()
+
     def draw(self):
+        if self.input != None:
+            self.buttons()
+
         self.screens[self.index][0].draw()
 
         if self.screens[self.index][1] == None:
             # let screen decide when it is done
             if self.screens[self.index][0].finished():
-                self.lastTime = time.time()
-                self.index = (self.index + 1) % len(self.screens)
-                self.done = (self.index == 0)
-                self.screens[self.index][0].restart()
+                self.switch_to(1, True)
         else:
             # use given timeout
             now = time.time()
             if ((now - self.lastTime) > self.screens[self.index][1]) or (now < self.lastTime):
-                self.lastTime = now
-                self.index = (self.index + 1) % len(self.screens)
-                self.done = (self.index == 0)
-                self.screens[self.index][0].restart()
+                self.switch_to(1, True)
 
 if __name__ == "__main__":
     from splash import SplashScreen

net.py

     def fail(self, f):
         self.failScreen = f
 
+    # Compatibility to Manager button events
+    def child_count(self, i):
+        self.request()
+        if self.response:
+            if hasattr(self.successScreen, "child_count"):
+                return self.successScreen.child_count(i)
+        else:
+            if hasattr(self.failScreen, "child_count"):
+                return self.failScreen.child_count(i)
+
+    # Compatibility to Manager button events
+    def switch_to(self, i, update_flag):
+        self.request()
+        if self.response:
+            if hasattr(self.successScreen, "switch_to"):
+                self.successScreen.switch_to(i, update_flag)
+        else:
+            if hasattr(self.failScreen, "switch_to"):
+                self.failScreen.switch_to(i, update_flag)
+
     def restart(self):
         self.start = time.time()
 

qr.py

 if __name__ == "__main__":
     import util
     import os
+    import sys
 
     t = util.getTarget()
 
     d = QRScreen(t, "http://ubabot.frubar.net", 10.0, "Drinks:", "tom-thumb", (255, 255, 255), (0, 0, 0))
 
-    # dump generated QR image to console, for embedding in Pico script
-    print("Dumping QR image to qr_tmp.py")
-    with open("qr_tmp.py", "w") as f:
-        f.write("# QR code image for \"" + d.data + "\"" + os.linesep)
-        f.write("# size:" + str(d.image.width) + "x" + str(d.image.height) + os.linesep)
-        f.write("qr_data = [" + os.linesep)
-        for y in range(0, d.image.height):
-            f.write("    [" + os.linesep)
-            for x in range(0, d.image.width):
-                s = str(d.image.getpixel((x, y)))
-                f.write("        " + s + "," + os.linesep)
-            f.write("    ]," + os.linesep)
-        f.write("]" + os.linesep)
+    try:
+        # dump generated QR image to console, for embedding in Pico script
+        print("Dumping QR image to qr_tmp.py")
+        with open("qr_tmp.py", "w") as f:
+            f.write("# QR code image for \"" + d.data + "\"" + os.linesep)
+            f.write("# size:" + str(d.image.width) + "x" + str(d.image.height) + os.linesep)
+            f.write("qr_data = [" + os.linesep)
+            for y in range(0, d.image.height):
+                f.write("    [" + os.linesep)
+                for x in range(0, d.image.width):
+                    s = str(d.image.getpixel((x, y)))
+                    f.write("        " + s + "," + os.linesep)
+                f.write("    ]," + os.linesep)
+            f.write("]" + os.linesep)
+    except Exception as e:
+        print()
+        if hasattr(sys, "print_exception"):
+            sys.print_exception(e)
+        else:
+            print(e)
+            print()
 
     t.loop(d.draw)