#!/usr/bin/env python

import sys, os
import array
import usb
import colorsys
import time
import math

busses = usb.busses()


VENDOR = 0x03eb
PRODUCT = 0x2300
IFACE = 0
EP_IN = 0x81
EP_OUT = 0x02


deltah = 0.0003
T = 0.00
PWMperADC = 33
BAR = 80

tstart = time.time()

def get_device():
    for bus in busses:
        devices = bus.devices
        for dev in devices:
            if dev.idVendor == VENDOR and dev.idProduct == PRODUCT:
                return dev
    return None


vmax = 1
vmin = 2**16
def adc(v):
    global vmax, vmin
    if v > vmax: vmax = v
    if v < vmin: vmin = v
    if vmax <= vmin: vmin -= 1

    t = time.time() - tstart
    hz = usbiocnt / t

    o = '% 4d Hz  ' % hz
    o += '#' * int( BAR * (v - vmin) / (vmax - vmin) )
    print o


usbiocnt = 0L
def usbio(dh, r, g, b):
    global usbiocnt
    usbiocnt += 1
    
    dout = array.array('B', [0]*4)

    dout[0] = 0xFF & 0x00
    dout[1] = 0xFF & (r)
    dout[2] = 0xFF & (g)
    dout[3] = 0xFF & (b)  

    dh.bulkWrite(EP_OUT, dout.tostring())

    #if usbiocnt % PWMperADC == 0:
    if 1:

        din = dh.bulkRead(EP_IN, 4)
        l = len(din)
        if l != 4:
            print "unexpected bulk read length: %d" % l
        else:
            if usbiocnt % PWMperADC == 0:
                adc( (din[2] << 8) + din[3] )


def intcol(v):
    v = int(v*256)
    if v > 255: v = 255
    if v < 0: v = 0
    return v


def rainbow(dh):

    h = 0. 
    s = 1.
    v = 1.
    
    while 1:
        if h > 1.:
            h = 0.
        else:
            h += deltah

        rgb = colorsys.hsv_to_rgb(h, s, v)
        (ri, gi, bi) = map(intcol, rgb)

        usbio(dh, ri, gi, bi)

        time.sleep(T)

 
def main():

    dev = get_device()
    dh = dev.open()
    dh.claimInterface(IFACE)

    rainbow(dh)

    dh.releaseInterface()
    del dh
    return 0


if __name__ == '__main__':
    sys.exit( main() )