How do I create a ROS UI with TkInter?

Brendon Lu and Benjamin Blinder

Make sure you have the following packages imported: tkinter and rospy. The tkinter module is a basic and simple, yet effective way of implementing a usable GUI.

import tkinter as tk
import rospy

Because tkinter has a hard time recognizing functions created at strange times, you should next create any functions you want to use for your node. For this example, I recommend standard functions to publish very simple movement commands.

You still need to initialize the ros node, as well as any publishers and subscribers, which should be the next step in your code.

Now it is time to create a basic window for your GUI. First, write [window name] = tk.Tk() to create a window, then set the title and size of the window. Not declaring a window size will create a window that adapts automatically to the size of whatever widgets you create on the window.

The step is to populate your window with the actual GUI elements, which tkinter calls "Widgets". Here we will be making two basic buttons, but there are other common widget types such as the canvas, entry, label, and frame widgets.

And now that you have created widgets, you will notice that if you run your code, it is still blank. This is because the widgets need to be added to the window. You can use "grid", "place", or "pack" to put the widget on the screen, each of which have their own strengths and weaknesses. For this example, I will be using "pack".

And now finally, you are going to run the tkinter mainloop. Please note that you cannot run a tkinter loop and the rospy loop in the same node, as they will conflict with each other.

To run the node we have created here, you should have your robot already running either in the simulator or in real life, and then simply use rosrun to run your node. Here is the code for the example tkinter node I created, with some more notes on what different parts of the code does

Although this code does technically move the robot and with some serious work it could run a much more advanced node, I do not recommend doing this. I would recommend that you create two nodes: A GUI node and a robot node. In the GUI node, create a custom publisher such as command_pub=rospy.Publisher('command', Twist, queue_size=1) and use this to send messages for movement to the robot node. This way, the robot node can handle things like LiDAR or odometry without issues, since the tkinter update loop will not handle those kinds of messages very efficiently.

Overall, tkinter is an industry staple for creating simple GUIs in Python, being fast, easy to implement, versatile, and flexible, all with an intuitive syntax. For more information, check out the links below.