Detect max quality level dynamically.

Detect max quality level dynamically.
This will select 2 for standard Pico 2's and 5 for standard Pico's.

PiCowbell_Camera_Demos/JPEG_Capture/code.py

@@ -76,8 +76,27 @@ def open_next_image():
         return open(filename, "wb")
 
 cam.colorspace = adafruit_ov5640.OV5640_COLOR_JPEG
-cam.quality = 3
-b = bytearray(cam.capture_buffer_size)
+
+# Different platforms have different amounts of memory available.
+# Typically a Pico 2 can handle quality = 2 and a Pico can handle quality = 5.  
+# Rather than detect and select sizes, let's try to detect the best dynamically 
+# for broader platform support. 
+# Start with the highest quality setting and attempt to allocate a buffer 
+# of the necessary size.  If it fails, try the next lowest.
+b = None
+for quality in range(2,55): #valid range is 2 to 54 inclusive
+    try:
+        cam.quality = quality
+        print(f"Attempting to use quality {quality}.")
+        b = bytearray(cam.capture_buffer_size)
+        print(f"Quality {quality} successfully selected.")
+        break
+    except Exception:
+        print(f"Quality {quality} was too big.  Trying next lowest.")
+
+if b==None:
+    print("There wasn't enough system memory to allocate the lowest quality buffer.")
+    
 jpeg = cam.capture(b)
 
 while True: