import smbus

bus = smbus.SMBus(1)

v = bus.read_byte_data(0x57, 0xff)
if v != 17:
        print "wrong part ID"
        exit(1)

bus.write_byte_data(0x57, 0x06, 0x03)

p = bus.read_byte_data(0x57, 0x07)
bus.write_byte_data(0x57, 0x07, (p & 0xfc) | 0x03)

p = bus.read_byte_data(0x57, 0x07)
bus.write_byte_data(0x57, 0x07, (p & 0xe3) | (0x01 << 2))

bus.write_byte_data(0x57, 0x09, 0x0f << 4 | 0x0f)

p = bus.read_byte_data(0x57, 0x07)
bus.write_byte_data(0x57, 0x07, p | (1 << 6))

alpha = 0.95
dcw = 0.0
lpf = [ 0.0, 0.0 ]
while True:
        buffer = bus.read_i2c_block_data(0x57, 0x05, 4)
        rawIRValue = (buffer[0] << 8) | buffer[1]
        rawRedValue = (buffer[2] << 8) | buffer[3]

        olddcw = dcw
        dcw = rawIRValue + alpha * dcw
        irACValue = dcw - olddcw

        lpf[0] = lpf[1]
        lpf[1] = (2.452372752527856026e-1 * (-irACValue)) + (0.50952544949442879485 * lpf[0])

        print (lpf[0] + lpf[1])