warning about unused images added, examples added to README.

README.md

@@ -1,7 +1,7 @@
 # Led-Badge-44x11
 Upload tool for an led name tag with USB-HID interface
 
-![LED Mini Board](green_badge.jpg)
+![LED Mini Board](photos/green_badge.jpg)
 
 ## Warning
 
@@ -34,12 +34,15 @@ loads the text 'Hello' as message one and 'World!' as message two. Note the diff
 
     sudo python3 ./led-badge-11x44.py -m 5 gfx/fablabnbg_logo_44x11.png
 
-loads a fullscreen still image.
+loads a fullscreen still image. (Or displays the pathname, if the image was not found. That is a hack. Sorry)
 
     sudo python3 ./led-badge-11x44.py -l gfx/heart.png -l gfx/fablab_logo_16x11.png  "I^Amy^Bfablab^B"
 
 preloads two images, a heart and a crude fablab logo as images 1 and two. The images can then be embedded in a message by using control characters. To enter the ^A control character on the shell, press CTRL-V followed by CTRL-A.
 
+![LED Mini Board](photos/love_my_fablab.jpg)
+
+
 <pre>
 Usage: led-badge-11x44.py [-h] [-s SPEED] [-m MODE] [-l FILE]
                           message [message ...]

led-badge-11x44.py

@@ -15,11 +15,12 @@
 # v0.1, 2019-03-05, jw  initial draught. HID code is much simpler than expected.
 # v0.2, 2019-03-07, jw  support for loading bitmaps added.
 # v0.3              jw  option -l to load graphics for inline use in text.
+# v0.4, 2019-03-08, jw  Warning about unused images added. Examples added to the README.
 
 import sys, os, re, array, time, argparse
 import usb.core
 
-__version = "0.3"
+__version = "0.4"
 
 font_11x44 = (
   # 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
@@ -151,13 +152,17 @@ for i in range(len(charmap)):
   char_offset[charmap[i]] = 11 * i
 
 bitmap_loaded = [ ([],0) ]
+bitmaps_unused = False
 
 def bitmap_char(ch):
   """ Returns a tuple of 11 bytes,
       ch = '_' returns (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255)
       The bits in each byte are horizontal, highest bit is left.
   """
-  if ord(ch) < 32: return bitmap_loaded[ord(ch)]
+  if ord(ch) < 32: 
+    global bitmaps_unused
+    bitmaps_unused = False
+    return bitmap_loaded[ord(ch)]
   o = char_offset[ch]
   return (font_11x44[o:o+11],1)
 
@@ -254,11 +259,15 @@ print("using [%s %s] bus=%d dev=%d" % (dev.manufacturer, dev.product, dev.bus, d
 if args.load:
   for file in args.load:
     bitmap_loaded.append(bitmap_img(file))
+    bitmaps_unused = True
 
 msgs = []
 for arg in args.message:
   msgs.append(bitmap(arg))
 
+if bitmaps_unused == True:
+  print("\nWARNING:\n Your preloaded images are not used.\n Try without '-l' or embed the control character '^A' in your message.\n")
+
 buf = array.array('B')
 buf.extend(header(list(map(lambda x: x[1], msgs)), args.speed, args.mode))