py9b/py9b/transport/base.py

"""Transport abstract class"""

def checksum(data):
	s = 0
	for c in data:
		s += c
	return (s & 0xFFFF) ^ 0xFFFF



class BaseTransport(object):
	MOTOR = 0x01
	ESC = 0x20
	BLE = 0x21
	BMS = 0x22
	EXTBMS = 0x23
	HOST = 0x3E
	
	DeviceNames = { MOTOR : "MOTOR", ESC : "ESC", BLE : "BLE", BMS : "BMS", EXTBMS : "EXTBMS", HOST : "HOST" }

	def __init__(self, link):
		self.link = link

	def recv(self):
		raise NotImplementedError()

	def send(self, src, dst, cmd, arg, data=""):
		raise NotImplementedError()

	def execute(self, command):
		self.send(command.request)
		if not command.has_response:
			return True
		#TODO: retry ?
		rsp = self.recv()
		return command.handle_response(rsp)

	@staticmethod
	def GetDeviceName(dev):
		return BaseTransport.DeviceNames.get(dev, "%02X" % (dev))


__all__ = ["checksum", "BaseTransport"]