Add 'plugins/USBPrinting/' from commit 'b28ca0881a'

git-subtree-dir: plugins/USBPrinting
git-subtree-mainline: 3823afd8cc
git-subtree-split: b28ca0881a

plugins/USBPrinting/avr_isp/ispBase.py

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+"""
+General interface for Isp based AVR programmers.
+The ISP AVR programmer can load firmware into AVR chips. Which are commonly used on 3D printers.
+
+ Needs to be subclassed to support different programmers.
+ Currently only the stk500v2 subclass exists.
+ This is a python 3 conversion of the code created by David Braam for the Cura project.
+"""
+
+from . import chipDB
+
+class IspBase():
+    """
+    Base class for ISP based AVR programmers.
+    Functions in this class raise an IspError when something goes wrong.
+    """
+    def programChip(self, flashData):
+        """ Program a chip with the given flash data. """
+        self.curExtAddr = -1
+        self.chip = chipDB.getChipFromDB(self.getSignature())
+        if not self.chip:
+            raise IspError("Chip with signature: " + str(self.getSignature()) + "not found")
+        self.chipErase()
+        
+        print("Flashing %i bytes" % len(flashData))
+        self.writeFlash(flashData)
+        print("Verifying %i bytes" % len(flashData))
+        self.verifyFlash(flashData)
+        print("Completed")
+
+    def getSignature(self):
+        """
+        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.
+        """
+        sig = []
+        sig.append(self.sendISP([0x30, 0x00, 0x00, 0x00])[3])
+        sig.append(self.sendISP([0x30, 0x00, 0x01, 0x00])[3])
+        sig.append(self.sendISP([0x30, 0x00, 0x02, 0x00])[3])
+        return sig
+
+    def chipErase(self):
+        """
+        Do a full chip erase, clears all data, and lockbits.
+        """
+        self.sendISP([0xAC, 0x80, 0x00, 0x00])
+
+    def writeFlash(self, flashData):
+        """
+        Write the flash data, needs to be implemented in a subclass.
+        """
+        raise IspError("Called undefined writeFlash")
+
+    def verifyFlash(self, flashData):
+        """
+        Verify the flash data, needs to be implemented in a subclass.
+        """
+        raise IspError("Called undefined verifyFlash")
+
+
+class IspError(BaseException):
+    def __init__(self, value):
+        self.value = value
+
+    def __str__(self):
+        return repr(self.value)