foo.py

   1 #!/usr/bin/env python
   2 import serial
   3 import sys
   4 import time
   5 ser = serial.Serial("/dev/ttyACM0", 57600)
   6
   7 #val = 0;
   8 #while True:
   9 #    ser.write('a')
  10 #    ser.write(chr(0))
  11 #    ser.write(chr(val))
  12 #    ser.write('\n')
  13 #    val+=1
  14 #    val%=256
  15 #    time.sleep(0.25);
  16
  17 while True:
  18     val = int(sys.stdin.readline())
  19     print 'a',
  20     print ord(chr(0)),
  21     print ord(chr(val))
  22     ser.write('a')
  23     ser.write(chr(0))
  24     ser.write(chr(val))
  25     ser.write('\n')
  26     print ser.readline()