car-rpm.py

from twisted.internet import reactor, task
from twisted.internet.protocol import Factory, Protocol
from twisted.internet.endpoints import TCP4ClientEndpoint
import re

class PlexKiwi(Protocol):
    def connectionMade(self):
        self.initializeConnection()

    testMode = ''
    pid = ''
    def sendCommand(self, testMode, pid):
        self.testMode = testMode
        self.pid = pid
        msg = '%s %s' % (("%#04x" % self.testMode)[2:].upper(), ("%#04x" % self.pid)[2:].upper())
        self.sendMessage(msg)

    def sendMessage(self, msg):
        self.transport.write('%s\r' % msg)

    initialized = False
    def initializeConnection(self):
        self.sendMessage('atz\r')
        self.sendMessage('ate0\r')
        self.initialized = False

    def askForRPM(self):
        self.sendCommand(0x01, 0x0C)

    responseString = re.compile('^([^>]*)>(.*?)$')
    buffer = ''
    def dataReceived(self, data):
        self.buffer += data
        while True:
            m = self.responseString.match(self.buffer)
            if not m:
                break
            if not self.initialized:
                self.buffer = m.group(2)
                self.initialized = True
            else:
                if m.group(1).strip() != '':
                    self.processResponse(m.group(1))
                self.buffer = m.group(2)

    def processResponse(self, response):
        r = response.split()
        readTestMode = int('0x%s' % r[2], 16)
        readPID = int('0x%s' % r[3], 16)
        if readTestMode - 0x40 == self.testMode:
            if readPID == self.pid:
                rpm = '0x%s' % ''.join(r[4:])
                rpm = int(rpm, 16) / 4
                print rpm

class PlexKiwiFactory(Factory):
    def buildProtocol(self, addr):
        return PlexKiwi()

point = TCP4ClientEndpoint(reactor, '192.168.0.10', 35000)
d = point.connect(PlexKiwiFactory())
def kickoff(protocol):
    t = task.LoopingCall(protocol.askForRPM)
    t.start(0.25)
d.addCallback(kickoff)
reactor.run()