Lost Step Counter

#!/usr/bin/python
import hal, time
import sys
from Tkinter import *
import tkMessageBox

root = Tk()
root.withdraw()
h = hal.component("miss_step")

count = 1
for opt in sys.argv[1:]:
    (dummy, count) = opt.split("=")
    if dummy != "count":
        count = 1

pins = []
for i in range(int(count)):
    p1 = "axis.%i.pos-cmd" %i
    p2 = "axis.%i.motor-pos-cmd" %i
    d = 0
    t = [p1, p2, d]
    pins.append(t)
    h.newpin(p1, hal.HAL_FLOAT, hal.HAL_IN)
    h.newpin(p2, hal.HAL_FLOAT, hal.HAL_IN)
    
h.ready()
try:
    flag = False
    while 1:
        time.sleep (1)
        for t in pins:
            if h[t[0]]-h[t[1]] != t[2]:
                flag = True
            t[2] = h[t[0]]-h[t[1]]
        if flag == True:
            flag = False
            message = ""
            for t in pins:
                message = message + t[0] + " = %f\n"%t[2]
            ret = tkMessageBox._show("Homing Position Differs",
                            message,
                           tkMessageBox.QUESTION, tkMessageBox.OK)
            root.update()
except KeyboardInterrupt:
    raise SystemExit

loadusr miss_step count=3

net check0 miss_step.axis.0.pos-cmd  axis.0.pos-cmd
net Xpos miss_step.axis.0.motor-pos-cmd