usb-lowlevel.py

#!/usr/bin/env python
#
# Basic example for Fadecandy, talking directly to the
# Teensy using PyUSB.
#
# Micah Elizabeth Scott
# This example code is released into the public domain.
#

import usb.core
import usb.util
import random
import time
import binascii

dev = usb.core.find(idVendor=0x1d50, idProduct=0x607a)
if not dev:
    raise IOError("No Fadecandy interfaces found")

dev.set_configuration()

print "Serial number: %s" % usb.util.get_string(dev, 255, dev.iSerialNumber)

# Debug flags

flags = 0x00
dev.write(1, '\x80' + chr(flags) + ('\x00' * 62))

# Set up a default color LUT

lut = [0] * (64 * 25)
for index in range(25):
    lut[index*64] = index | 0x40
lut[24*64] |= 0x20
for channel in range(3):
    for row in range(257):
        value = min(0xFFFF, int(pow(row / 256.0, 2.2) * 0x10000))
        i = channel * 257 + row
        packetNum = i / 31
        packetIndex = i % 31
        #print "%d, %d = 0x%04x" % (channel, row, value)
        lut[packetNum*64 + 2 + packetIndex*2] = value & 0xFF
        lut[packetNum*64 + 3 + packetIndex*2] = value >> 8
lutPackets = ''.join(map(chr, lut))
#print binascii.b2a_hex(lutPackets)
dev.write(1, lutPackets)
print "LUT programmed"

# Slowly push random frames to the device

while True:

    for index in range(25):
        if index == 24:
            # Final
            control = index | 0x20
        else:
            control = index

        data = chr(control) + ''.join(chr(random.choice([0, 255])) for i in range(63))
        dev.write(1, data)
        #print binascii.b2a_hex(data)

    #print
    raw_input()
    #time.sleep(0.1)