serialProcess.py

from array import *
import serial
import time
import multiprocessing
import sqlite3

conn=sqlite3.connect('rover.db')
curs=conn.cursor()

class SerialProcess(multiprocessing.Process):

    def __init__(self, taskQ, resultQ):
        multiprocessing.Process.__init__(self)
        self.taskQ = taskQ
        self.resultQ = resultQ
        self.usbPort = '/dev/ttyAMA0'
        self.sp = serial.Serial(self.usbPort, 2400, timeout=1)

    def close(self):
        self.sp.close()

    def sendData(self, data):
        print "sendData start..."
        self.sp.write(data)
        time.sleep(3)
        print "sendData done: " + data

    def run(self):

        self.sp.flushInput()

        while True:
            # look for incoming tornado request
            if not self.taskQ.empty():
                task = self.taskQ.get()

                # send it to the arduino
        self.sp.write(task)
        print "received from client, sending to radio:  JOYSTICK_X  " + str(ord(task[1])) + "    JOYSTICK_Y:  " + str(ord(task[2]))

            # look for incoming serial data
            if (self.sp.inWaiting() > 0):
        receivedArray = bytes()
        while (self.sp.inWaiting()):
            receivedArray = receivedArray + self.sp.read(1)

        # encode string to two utf-8 characters (A through P) per byte
        encoded = bytes()
        index = 0
        while (index < len(receivedArray)):
            encoded += chr(ord(receivedArray[index]) / 16 + 65)
            encoded += chr(ord(receivedArray[index]) % 16 + 65)
            index += 1
        if (len(receivedArray) == 2):
            curs.execute("INSERT INTO pings values((?), (?))", (ord(receivedArray[0]), ord(receivedArray[1])))
            conn.commit()

        # send it to tornado
        self.resultQ.put(encoded)