#
# hello.step.45.py
#
# receive and display step response (edited)
# hello.step.45.py serial_port
#
# Neil Gershenfeld
# CBA MIT 7/19/09
# 
# edited by Ryan Castonia
#
# (c) Massachusetts Institute of Technology 2009
# Permission granted for experimental and personal use;
# license for commercial sale available from MIT
#

from Tkinter import *
import serial

WINDOW = 600
NSAMPLES = 254
MAX = 1040
saveflag = 0
index = 0
path = []
step = []
path_filt = []
step_filt = []
baseline = []
yscale = 1
xscale = 1
yoffset = 1
xoffset = 1
eps = .9

def idle(parent,canvas):
   global index, channel, baseline, path, path_filt, step, step_filt, saveflag
   #
   # idle routine
   #
   
   lo_dn = ord(ser.read())
   hi_dn = ord(ser.read())
   lo_up = ord(ser.read())
   hi_up = ord(ser.read())
   if ((lo_dn == 1) & (hi_dn == 2) & (lo_up == 3) & (hi_up == 4)):
      if (path_filt == []):
         path_filt = path
         step_filt = step
      else:
         for i in range(len(path_filt)):
            path_filt[i] = (1-eps)*path_filt[i] + eps*path[i]
         for i in range(len(step_filt)):
            step_filt[i] = (1-eps)*step_filt[i] + eps*step[i]
      if (step_filt[1] > 600):
         canvas.itemconfigure("alert",text="You lose!!!")
      if (300< step_filt[1] < 600):
         canvas.itemconfigure("alert",text="Wait for reset")
      if (step_filt[1] < 300):
         canvas.itemconfigure("alert",text="Go")
      canvas.coords('x0',0,.95*WINDOW,step_filt[0],WINDOW)
      index = 0
      path = []
      step = []
   else:
      value_up = 256*hi_up + lo_up
      value_dn = 256*hi_dn + lo_dn
      value = (value_up + (1023-value_dn))/2.0
      index += 2
      step.insert(0,value)
      y = WINDOW-(yscale*(value/float(MAX)+yoffset))*WINDOW
      x = WINDOW-(xscale*(index/float(NSAMPLES)-xoffset))*WINDOW
      path.insert(0,y)
      path.insert(0,x)
   parent.after_idle(idle,parent,canvas)

def save_data(parent):
   global saveflag
   saveflag = 1

def store_baseline(parent):
   global path_filt, baseline
   baseline = []
   for i in range(len(path_filt)):
      baseline.append(path_filt[i])

#
# check command line arguments
#
if (len(sys.argv) != 2):
   print "command line: python hello.step.45.py serial_port"
   sys.exit()
port = sys.argv[1]
#
# open serial port
#
ser = serial.Serial(port,9600)
ser.setDTR()
ser.flush()
#
# find framing
#
print "finding framing ..."
byte2 = 0
byte3 = 0
byte4 = 0
while 1:
   byte1 = byte2
   byte2 = byte3
   byte3 = byte4
   byte4 = ord(ser.read())

   if ((byte1 == 1) & (byte2 == 2) & (byte3 == 3) & (byte4 == 4)):
      print "start plotting"
      break
#
# set up GUI
#
root = Tk()
root.title('hello.step.45.py')
root.bind('q','exit')
canvas = Canvas(root, width=WINDOW, height=WINDOW, background='white')
canvas.create_text(.5*WINDOW,.7*WINDOW,font=("Helvetica", 24),tags="alert",fill="#0000b0")
canvas.pack()
#
ioframe = Frame(root)
quitbtn = Button(ioframe, text="quit")
quitbtn.bind('<Button-1>','exit')
quitbtn.pack(side="left")
ioframe.pack()
#
# start idle loop
#
root.after(100,idle,root,canvas)
root.mainloop()