#!/usr/bin/env python2.7 import sys, serial, struct port = '/dev/ttyACM0' sp = serial.Serial(port, baudrate=115200, bytesize=serial.EIGHTBITS, parity=serial.PARITY_NONE, xonxoff=False, rtscts=False, stopbits=serial.STOPBITS_ONE, timeout=None, dsrdtr=True) sp.setDTR(True) # dsrdtr is ignored on Windows. sp.write("snap") sp.flush() size = struct.unpack('