#
# hello.temp.45.py
#
# receive and display temperature
# hello.temp.45.py serial_port
#
# Neil Gershenfeld
# CBA MIT 3/27/12
#
# (c) Massachusetts Institute of Technology 2012
# Permission granted for experimental and personal use;
# license for commercial sale available from MIT
#

from Tkinter import * #from Tkinter import *
from numpy import log
import serial

WINDOW = 1200 # window size #was 600
eps = 0.5 # filter time constant
filter = 0.0#filtered value 0.0

def idle(parent,canvas):
   # print "hi in here"
   global filter, eps

   line = ser.readline()
  #print line
   # first_char = line[:1]
   try:
      value = int(line)#float(line[1:])
     #print value
      filter = (1-eps)*filter + eps*value
      x = int(.2*WINDOW + (.9-.2)*WINDOW*(filter-100.0)/800.0) # delta = 800, starts at 100
    #print "x is" + x

      canvas.itemconfigure("text1",text=int(filter))                #("text1",text="%.2f"%filter)
      canvas.coords('rect1',.2*WINDOW,.05*WINDOW,x,.2*WINDOW) #canvas.coords('rect1',.2*WINDOW,.05*WINDOW,x,.2*WINDOW)
      canvas.coords('rect2',x,.05*WINDOW,.9*WINDOW,.2*WINDOW) #canvas.coords('rect2',x,.05*WINDOW,.9*WINDOW,.2*WINDOW)
      canvas.update()

   except:
      print "Error with: " + line

   parent.after_idle(idle,parent,canvas)

#
#  check command line arguments
#
if (len(sys.argv) != 2):
   sys.exit()
port = sys.argv[1]
#
# open serial port
#
ser = serial.Serial(port,9600)
ser.setDTR()
#
# start plotting
#
root = Tk()
root.title('Capacitance') #root.title('hello.temp.45.py (q to exit)')
root.bind('q','exit')
canvas = Canvas(root, width=WINDOW, height=.25*WINDOW, background='white') #canvas = Canvas(root, width=WINDOW, height=.25*WINDOW, background='white')
canvas.create_text(.1*WINDOW,.1*WINDOW,font=("Helvetica", 30, "bold"),text="Capacitance",fill="#000000")
canvas.create_text(.1*WINDOW,.125*WINDOW,text=".33",font=("Helvetica", 24),tags="text1",fill="#000000")
canvas.create_rectangle(.2*WINDOW,.05*WINDOW,.3*WINDOW,.2*WINDOW, tags='rect1', fill='#b00000') #canvas.create_rectangle(.2*WINDOW,.05*WINDOW,.3*WINDOW,.2*WINDOW, tags='rect1', fill='#b00000')
canvas.create_rectangle(.3*WINDOW,.05*WINDOW,.9*WINDOW,.2*WINDOW, tags='rect2', fill='#F0F8FF')#canvas.create_rectangle(.3*WINDOW,.05*WINDOW,.9*WINDOW,.2*WINDOW, tags='rect2', fill='#0000b0')
canvas.pack()
root.after(100,idle,root,canvas)
root.mainloop()