First draft of transmit function based on standard python

host/host.py

@@ -0,0 +1,32 @@
+from pyusb import usb
+import colorsys
+import numpy as np
+
+CRATE_WIDTH = 5
+CRATE_HEIGHT = 4
+CRATES_X = 16
+CRATES_Y = 2
+DISPLAY_WIDTH = CRATES_X * CRATE_WIDTH
+DISPLAY_HEIGHT = CRATES_Y * CRATE_HEIGHT
+FRAME_SIZE = CRATE_WIDTH*CRATE_HEIGHT*3
+
+dev = usb.core.find(idVendor=0x1cbe, idProduct=0x0003)
+
+def sendframe(framedata):
+    """ Send a frame to the display
+
+    The argument contains a h * w array of 3-tuples of (r, g, b)-data
+    """
+    def chunks(l, n):
+        for i in xrange(0, len(l), n):
+            yield l[i:i+n]
+
+    for cx, cy in itertools.product(range(16), range(2)):
+        data = [ v for x in range(CRATE_WIDTH) for y in range(CRATE_HEIGHT) for v in framedata[cy*CRATE_HEIGHT + y][cx*CRATE_WIDTH + x] ]
+        if len(data) != FRAME_SIZE:
+            raise ValueError('Invalid frame data. Expected {} bytes, got {}.'.format(FRAME_SIZE, len(data)))
+        # Send framebuffer data
+        dev.write(0x01, bytes([0, x, y])+bytes(data))
+    # Send latch command
+    dev.write(0x01, b'\x01')
+