#
# hello3.step.py
# receive and plot step response
# Neil Gershenfeld CBA MIT
# 10/29/05
#
from Tkinter import *
import serial

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

i = 0
samples = []
calbsamples = []
isCalibrated = False
calbValue = 0.0

def idle(parent,canvas):
   global index, channel, baseline, path, path_filt, step, step_filt, saveflag
   global samples, calbsamples, calbValue, isCalibrated
   #
   # idle routine
   #
   #eps = float(sfilter.get())
   
   lowbits = ord(ser.read())
   hibits = ord(ser.read())

   

   one = ord(ser.read())
   two = ord(ser.read())
   three = ord(ser.read())
   four = ord(ser.read())

   while 1:
      one = two
      two = three 
      three = four 
      four = ord(ser.read())
      if ((one == 1) & (two == 2) & (three == 3) & (four == 4)):
         print "got framing @#"
 	 break


   print "one two three four:", one, ",", two, ",", three, ",", four
   print "low:", lowbits, " hibits:", hibits 
   voltage = 256*hibits + lowbits
   voltageAD = voltage
   print "voltage A/D: " , voltage
   
   voltage = float(voltage/1023.0)   
   voltage = voltage * 5.0   
   print "Voltage Real: ", voltage

   

   #if isCalibrated == False:
   #   calbsamples.append(voltageAD)
   #   canvas.itemconfigure("y0",text="Calibrating sample %d of 40."%len(calbsamples))    
   #   if len(calbsamples) == 40:
   #      isCalibrated = True
   #      sum = 0.0
   #     for samp in calbsamples:
   #         sum += samp
   #      calbValue = sum/40.0


   #if isCalibrated:
   #   samples.append(voltageAD)
   #   if len(samples) == 10:
      
   #      sum = 0.0
   #      for samp in samples:
   #         sum = sum + samp
   #      avg = sum/10.0
   #      samples = []
   #      print "10 sample average is %d" %avg
   #      if avg > (calbValue+1):
   #         canvas.itemconfigure("y0",text="There is someting on the scale. avg: %d"%avg)
   #      else:
   #         canvas.itemconfigure("y0",text="Nothing on scale. avg: %d"%avg)            

   canvas.itemconfigure("y0",text="Distance: %d (higher number is closer)"%voltageAD)

   
   


   parent.after_idle(idle,parent,canvas)


#
# open serial port
#
#ser = serial.Serial('/dev/ttyUSB0',9600)
ser = serial.Serial('/dev/ttyS0',9600)
#ser = serial.Serial('COM1',9600)
ser.setDTR()
#
# 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
#
# start plotting
#
root = Tk()
root.title('voltmeter')
root.bind('q','exit')

canvas = Canvas(root, width=WINDOW, height=.2*WINDOW, background='yellow')
canvas.create_text(.5*WINDOW,.1*WINDOW,font=("Helvetica", 24),tags="y0",fill="#0000b0")
canvas.pack()

ioframe = Frame(root)

ioframe.pack()

root.after(100,idle,root,canvas)
root.mainloop()