#
# hello4.ad.py
# receive and display A/D readings
# Neil Gershenfeld CBA MIT
# 10/29/06
#
from Tkinter import *
import serial

WIDTH = 600
NPTS = 100
HEIGHT = 400
count = 0
path = []

def idle(parent,canvas):
   global count, path, baseline, offset, gain, filter
   #
   # idle routine
   #
   lo = ord(ser.read())
   hi = ord(ser.read())
   value = 255*hi + lo
   baseline = filter*value + (1-filter)*baseline
   canvas.itemconfigure("value",text="%d"%value)
   y = HEIGHT*(1-(offset+gain*(value-baseline))/1024.)
   path.append(WIDTH*count/(NPTS-1.0))
   path.append(y)
   count += 1
   if (count == NPTS):
      #
      # update plot
      #
      canvas.delete("path")
      canvas.create_line(path,tag="path",width=3,fill="#00b000")
      count = 0
      path = []
      filter = float(wfilter.get())
      offset = float(woffset.get())
      gain = float(wgain.get())
      sbaseline.set("baseline: %.2f filter:"%baseline)
      #
      # find framing
      # 
      ser.flushInput()
      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)):
	    break
   parent.after_idle(idle,parent,canvas)


#
# open serial port
#
#ser = serial.Serial('/dev/ttyUSB0',9600)
ser = serial.Serial('/dev/ttyUSB0',115200)
#ser = serial.Serial('/dev/ttyS0',9600)
#ser = serial.Serial('/dev/ttyS0',115200)
#ser = serial.Serial('COM6',9600)
ser.setDTR()
#
# set up GUI
#
root = Tk()
root.title('hello4.ad.py')
root.bind('q','exit')
#
canvas = Canvas(root, width=WIDTH, height=HEIGHT, background='white')
canvas.create_text(.5*WIDTH,.95*HEIGHT,font=("Helvetica", 30),tags="value",fill="#0000b0")
canvas.pack()
#
control_frame = Frame(root)
sbaseline = StringVar()
wbaseline = Label(control_frame, textvariable=sbaseline)
wbaseline.pack(side="left")
wfilter = Scale(control_frame,from_=0,to=.1,resolution=.01,orient=HORIZONTAL)
filter = 0
wfilter.set(filter)
wfilter.pack(side='left')
Label(control_frame, text=" offset: ").pack(side="left")
woffset = Scale(control_frame,from_=-1024,to=1024,resolution=1,orient=HORIZONTAL)
offset = 0
baseline = 0
woffset.set(offset)
woffset.pack(side='left')
Label(control_frame, text=" gain: ").pack(side="left")
wgain = Scale(control_frame,from_=1,to=100,resolution=1,orient=HORIZONTAL)
gain = 1
wgain.set(gain)
wgain.pack(side='left')
quitbtn = Button(control_frame, text="quit")
quitbtn.bind('<Button-1>','exit')
quitbtn.pack(side="left")
control_frame.pack()
#
# find framing
# 
ser.flushInput()
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)):
      break
#
# start plotting
#
root.after(100,idle,root,canvas)
root.mainloop()