#Serial.readline seems unreliable at times tooĬ = ser. Log = Text ( root, width=30, height=30, takefocus=0)

Setting speed to 1.' print 'Setting servo '+str ( n) +' speed to '+str ( speed) +' out of 127.' print 'WARNING: Angle range should be between 0 and 180. # make a text box to put the serial output Serial ( port'/dev/tty.Pololu', baudrate9600, bytesize8, parity'N', stopbits1, timeout1) print 'WARNING: Speed should be between 0 and 127. Ser = Serial(serialPort, baudRate, timeout=0, writeTimeout=0) #ensure non-blocking This problem can be avoided with the timeout=0 option when enitializing the Serial object, which will cause it to return nothing unless something is already waiting in the Serial object's buffer. For example, a Serial.readline() won't print anything until there is a whole line to return, which in some cases might be never! Even using the after() and update() methods will still not allow the UI to be updated in this case, since the function never ends. Normally, the Serial.read() and Serial.readline() will hold up the whole program until it has enough information to give. However, the real issue is making sure that reading from serial is non-blocking. Both methods achieve basically the same goal of updating the GUI. Alternatively, you could write your own infinite loop, and call root.

If you are running your own infinite loop anywhere in the code, the GUI will freeze up. It needs the things in there to run every now and then in order to make the interface respond to interactions. mainloop() method, it is running its own while loop. Keep in mind that when TkInter gets to the root. after(milliseconds) method to run a non-blocking version of read in the tkinter main loop. The process cannot update buttons or react to input because it is busy waiting for the serial to say something.

Note Each new client connection must create a new instance as this object (and the RFC 2217 protocol) has internal state. However, waiting for input from pySerial's Serial object is blocking, which means that it will prevent your GUI from being responsive. Usage examples can be found in the examples where two TCP/IP - serial converters are shown, one using threads (the single port server) and an other using select (the multi port server). To use Python as a graphical interface for an Arduino powered robot, programmatically read the USB with the pySerial library.

Python serial inwaiting example