Interface and application programming

hello.reflect.45 to blender

Getting blender to read from the serial port in Debian 7.0 (Wheezy) wasn’t easy, but now it works really nice. Here is what I did:

Step 1. Download blender. I used blender 2.56a for Linux 64-bit (I will try, but I’m sure it works for 2.66 as well). I install and run it like this:

  sudo mv ~/Downloads/blender-2.65a-linux-glibc211-x86_64.tar.bz2 /opt/
  sudo tar -xf /opt/blender-2.65a-linux-glibc211-x86_64.tar.bz2 
  /opt/blender-2.65a-linux-glibc211-x86_64/blender

Step 2. I added an always sensor (in pulse mode)

my picture

to a cube that triggers the following python script:

sys.path.append('/usr/local/bin/blender-2.65a-linux-glibc211-x8664/2.65/python/lib/python3.3/site-
packages/pyserial-2.6')
sys.path.append('/usr/local/bin/blender-2.65a-linux-glibc211-x8664/2.65/python/lib/python3.3/site-
packages/pyserial-2.6/serial')
 
import bge
import serial
import GameLogic
 
eps = 0.2 # filter time constant
filter = 0.0 # filtered value
nloop = 100.0 # number of loops accumulated
amp = 25.0 # difference amplitude
 
def reflect():
   global filter, eps
   #
   # idle routine
   #
   byte2 = 0
   byte3 = 0
   byte4 = 0
   GameLogic.SerialPort.flush()
   while 1:
      #
      # find framing 
      #
      byte1 = byte2
      byte2 = byte3
      byte3 = byte4
      byte4 = ord(GameLogic.SerialPort.read())
      if ((byte1 == 1) & (byte2 == 2) & (byte3 == 3) & (byte4 == 4)):
         break
   onlow = ord(GameLogic.SerialPort.read())
   onhigh = ord(GameLogic.SerialPort.read())
   onvalue = (256*onhigh + onlow)/nloop
   print ("on", onvalue)
   offlow = ord(GameLogic.SerialPort.read())
   offhigh = ord(GameLogic.SerialPort.read())
   offvalue = (256*offhigh + offlow)/nloop
   print ("off", offvalue)
   filter = (1-eps)filter + epsamp*(on_value-off_value)
   print ("diff", filter)
 
 
port = '/dev/ttyUSB0' 
pin = 0 
try: 
    GameLogic.SerialPort 
except: 
    GameLogic.SerialPort = serial.Serial(port,9600)
    GameLogic.SerialPort.setDTR()
 
reflect()
 
# To get the controller thats running this python script:
cont = bge.logic.getCurrentController() # bge.logic is automatically imported
 
# To get the game object this controller is on:
obj = cont.owner
obj.worldPosition.z = filter/10
It is basically Neil’s hello.reflect.45.py with some extras.

Step 3. Blender’s bundeled python doesn’t come with pyserial, so you have to install it manually. This thread helped me a lot for making this work. Big thank you to abhi! I downloaded pyserial 2.6 and copied it to 

  /opt/blender-2.66a-linux-glibc211-x86_64/2.66/python/lib/python3.3/site-packages/

I put the path to the pyserial module in the script

sys.path.append(‘/opt/blender-2.65a-linux-glibc211-x86_64/2.65/python/lib/python3.3/site-
packages/pyserial-2.6’)

Step 4. In the file 

  /opt/blender-2.65a-linux-glibc211-x86_64/2.65/python/lib/python3.3/site-packages/serial/serialposix.py

line 62,
I changed octal to hexadecimal notation

  baudrate_constants = dict([ (0, 0x0000), (50, 0x0001), (75, 0x0002), (110, 0x0003),\
  (134, 0x0004), (150, 0x0005), (200, 0x0006), (300, 0x0007),\
  (600, 0x0008), (1200, 0x0009), (1800, 0x000A), (2400, 0x000B),\
  (4800, 0x000C), (9600, 0x000D), (19200, 0x000E), (38400, 0x000F),\
  ('BOTHER', 0x1000), (57600, 0x1001), (115200, 0x1002), (230400, 0x1003),\
  (460800, 0x1004), (500000, 0x1005), (576000, 0x1006), (921600, 0x1007),\
  (1000000, 0x1008), (1152000, 0x1009), (1500000, 0x100A), (2000000, 0x100B),\
  (2500000, 0x100C), (3000000, 0x100D), (3500000, 0x100E), (4000000, 0x100F) ])

Step 5. Change all the “except Exception, msg:” to “except Exception as msg:” and similar instructions.

Step 6. In the file /opt/blender-2.65a-linux-glibc211-x86_64/2.65/python/lib/python3.3/site-packages/serial/serialutil.py”
line 292,
comment the if as shown below 

  #if isinstance(port, basestring):  
  self.portstr = port  
  #else:  
  #self.portstr = self.makeDeviceName(port)

Step 7. Change all the ” except TypeError, err:” to ” except TypeError as err:” and similar instructions.

This will work, but for not opening the serial port on every frame of bge cycle I used a separate init script called only once at the beginning.

hello.reflect.45 to puredata

I used the “SimpleExample.pd” from the tutorial Pure Data to Arduino Over Serial

my picture

Since it receives the 1234’s and the separate byte values all together it just makes some funny noises. I will work on separating it all nicely.