'Get the AVR signature from the chip. This is a 3 byte array which describes which chip we are connected to.
This is important to verify that we are programming the correct type of chip and that we use proper flash block sizes.'

def getSignature(self):

    sig = []
    sig.append(self.sendISP([48, 0, 0, 0])[3])
    sig.append(self.sendISP([48, 0, 1, 0])[3])
    sig.append(self.sendISP([48, 0, 2, 0])[3])
    return sig
