def create_blockList(self, payload, blockSize):
blockList = []
currBlock = []
currPdu = []
payloadPtr = 0
blockPtr = 0
payloadLength = len(payload)
pduLength = self.__maxPduLength
blockLength = blockSize * pduLength
working = True
while (working):
if (payloadPtr + pduLength) >= payloadLength:
working = False
currPdu = fillArray(payload[payloadPtr:], pduLength)
currBlock.append(currPdu)
blockList.append(currBlock)
if working:
currPdu = payload[payloadPtr:payloadPtr + pduLength]
currBlock.append(currPdu)
payloadPtr += pduLength
blockPtr += pduLength
if (blockPtr == blockLength):
blockList.append(currBlock)
currBlock = []
blockPtr = 0
return blockList
def create_blockList(self, payload):
blockList = []
currBlock = []
payloadLength = len(payload)
counter = 0
for i in range(0, payloadLength):
currBlock.append(payload[i])
counter += 1
if counter == self.__maxPduLength:
blockList.append(currBlock)
counter = 0
currBlock = []
if len(currBlock) is not 0:
blockList.append(fillArray(currBlock, self.__maxPduLength))
return blockList
def send(self, payload, functionalReq=False): # TODO: functionalReq not used???
#self.__connection.send(payload) # .... implemented in the LIN bus impl, so the rest of function replaced by this
payloadLength = len(payload)
if payloadLength > LINTP_MAX_PAYLOAD_LENGTH:
raise Exception("Payload too large for CAN Transport Protocol")
if payloadLength <= self.__maxPduLength:
state = LinTpState.SEND_SINGLE_FRAME
else:
# we might need a check for functional request as we may not be able to service functional requests for
# multi frame requests
state = LinTpState.SEND_FIRST_FRAME
firstFrameData = payload[0:self.__maxPduLength-1]
cfBlocks = self.create_blockList(payload[5:])
sequenceNumber = 1
txPdu = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
endOfMessage_flag = False
## this needs fixing to get the timing from the config
timeoutTimer = ResettableTimer(1)
stMinTimer = ResettableTimer(self.__STMin)
self.clearBufferedMessages()
timeoutTimer.start()
while endOfMessage_flag is False:
rxPdu = self.getNextBufferedMessage()
if rxPdu is not None:
raise Exception("Unexpected receive frame")
if state == LinTpState.SEND_SINGLE_FRAME:
txPdu[N_PCI_INDEX] += (LinTpMessageType.SINGLE_FRAME << 4)
txPdu[SINGLE_FRAME_DL_INDEX] += payloadLength
txPdu[SINGLE_FRAME_DATA_START_INDEX:] = fillArray(payload, self.__maxPduLength)
self.transmit(txPdu)
endOfMessage_flag = True
elif state == LinTpState.SEND_FIRST_FRAME:
payloadLength_highNibble = (payloadLength & 0xF00) >> 8
payloadLength_lowNibble = (payloadLength & 0x0FF)
txPdu[N_PCI_INDEX] += (LinTpMessageType.FIRST_FRAME << 4)
txPdu[FIRST_FRAME_DL_INDEX_HIGH] += payloadLength_highNibble
txPdu[FIRST_FRAME_DL_INDEX_LOW] += payloadLength_lowNibble
txPdu[FIRST_FRAME_DATA_START_INDEX:] = firstFrameData
self.transmit(txPdu)
state = LinTpState.SEND_CONSECUTIVE_FRAME
stMinTimer.start()
timeoutTimer.restart()
elif state == LinTpState.SEND_CONSECUTIVE_FRAME:
if(
stMinTimer.isExpired() and
(self.__transmitBuffer is None)
):
txPdu[N_PCI_INDEX] += (LinTpMessageType.CONSECUTIVE_FRAME << 4)
txPdu[CONSECUTIVE_FRAME_SEQUENCE_NUMBER_INDEX] += sequenceNumber
txPdu[CONSECUTIVE_FRAME_SEQUENCE_DATA_START_INDEX:] = cfBlocks.pop(0)
self.transmit(txPdu)
sequenceNumber = (sequenceNumber + 1) % 16
stMinTimer.restart()
timeoutTimer.restart()
if len(cfBlocks) == 0:
endOfMessage_flag = True
txPdu = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
sleep(0.001)
if timeoutTimer.isExpired(): raise Exception("Timeout")
def send(self, payload, functionalReq=False):
payloadLength = len(payload)
payloadPtr = 0
state = CanTpState.IDLE
if payloadLength > CANTP_MAX_PAYLOAD_LENGTH:
raise Exception("Payload too large for CAN Transport Protocol")
if payloadLength < self.__maxPduLength:
state = CanTpState.SEND_SINGLE_FRAME
else:
# we might need a check for functional request as we may not be able to service functional requests for
# multi frame requests
state = CanTpState.SEND_FIRST_FRAME
txPdu = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
sequenceNumber = 1
endOfMessage_flag = False
blockList = []
currBlock = []
## this needs fixing to get the timing from the config
timeoutTimer = ResettableTimer(1)
stMinTimer = ResettableTimer()
self.clearBufferedMessages()
while endOfMessage_flag is False:
rxPdu = self.getNextBufferedMessage()
if rxPdu is not None:
N_PCI = (rxPdu[0] & 0xF0) >> 4
if N_PCI == CanTpMessageType.FLOW_CONTROL:
fs = rxPdu[0] & 0x0F
if fs == CanTpFsTypes.WAIT:
raise Exception("Wait not currently supported")
elif fs == CanTpFsTypes.OVERFLOW:
raise Exception("Overflow received from ECU")
elif fs == CanTpFsTypes.CONTINUE_TO_SEND:
if state == CanTpState.WAIT_FLOW_CONTROL:
if fs == CanTpFsTypes.CONTINUE_TO_SEND:
bs = rxPdu[FC_BS_INDEX]
if (bs == 0):
bs = 585
blockList = self.create_blockList(
payload[payloadPtr:], bs)
stMin = self.decode_stMin(
rxPdu[FC_STMIN_INDEX])
currBlock = blockList.pop(0)
state = CanTpState.SEND_CONSECUTIVE_FRAME
stMinTimer.timeoutTime = stMin
stMinTimer.start()
timeoutTimer.stop()
else:
raise Exception(
"Unexpected Flow Control Continue to Send request"
)
else:
raise Exception("Unexpected fs response from ECU")
else:
raise Exception("Unexpected response from device")
if state == CanTpState.SEND_SINGLE_FRAME:
txPdu[N_PCI_INDEX] += (CanTpMessageType.SINGLE_FRAME << 4)
txPdu[SINGLE_FRAME_DL_INDEX] += payloadLength
txPdu[SINGLE_FRAME_DATA_START_INDEX:] = fillArray(
payload, self.__maxPduLength)
self.transmit(txPdu, functionalReq)
endOfMessage_flag = True
elif state == CanTpState.SEND_FIRST_FRAME:
payloadLength_highNibble = (payloadLength & 0xF00) >> 8
payloadLength_lowNibble = (payloadLength & 0x0FF)
txPdu[N_PCI_INDEX] += (CanTpMessageType.FIRST_FRAME << 4)
txPdu[FIRST_FRAME_DL_INDEX_HIGH] += payloadLength_highNibble
txPdu[FIRST_FRAME_DL_INDEX_LOW] += payloadLength_lowNibble
txPdu[FIRST_FRAME_DATA_START_INDEX:] = payload[0:self.
__maxPduLength -
1]
payloadPtr += self.__maxPduLength - 1
self.transmit(txPdu, functionalReq)
timeoutTimer.start()
state = CanTpState.WAIT_FLOW_CONTROL
elif state == CanTpState.SEND_CONSECUTIVE_FRAME:
if (stMinTimer.isExpired()):
txPdu[N_PCI_INDEX] += (
CanTpMessageType.CONSECUTIVE_FRAME << 4)
txPdu[
CONSECUTIVE_FRAME_SEQUENCE_NUMBER_INDEX] += sequenceNumber
txPdu[
CONSECUTIVE_FRAME_SEQUENCE_DATA_START_INDEX:] = currBlock.pop(
0)
payloadPtr += self.__maxPduLength
self.transmit(txPdu, functionalReq)
sequenceNumber = (sequenceNumber + 1) % 16
stMinTimer.restart()
if (len(currBlock) == 0):
if (len(blockList) == 0):
endOfMessage_flag = True
else:
timeoutTimer.start()
state = CanTpState.WAIT_FLOW_CONTROL
#print("waiting for flow control")
txPdu = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
# timer / exit condition checks
if (timeoutTimer.isExpired()):
raise Exception("Timeout waiting for message")
sleep(0.001)
