When working with microcontrollers, especially helping students debug their work, I hate having to open device manager or a serial terminal to search for the serial port name of the device I most recently plugged in. I wrote a small python script to hook into Window’s notification system to know when a new COM port has been plugged in, and then display its name in a popup window.
The first step in this was to find out when something is plugged in. I tried all sorts of things with windows event viewer to see if I could detect this because I didn’t want to have yet another service running in the background on my PC eating resources all the time, and I wanted the reaction to be fast, so polling every 10 seconds or something would be too long to wait for a popup. Alas, I couldn’t find any way to get USB port data to trigger an event in windows when you plug in a USB port.
Looking online for examples I only seemed to find C# or VS code. I’m not installing anything more to develop this one project, and at first I wanted to see if there was a cross-platform solution since I was going to have to write it all from scratch. Eventually I settled on a windows-only solution because I found an excellent site that is full of good code examples for win32 python interfacing from a user’s post on stackoverflow. these kinds of sites are few and far between, so I’m glad I came across it! This code example connects into Windows Notification center and WMI (Windows Management Interface) to detect when USB items are plugged in. You can detect drives, networking, and serial ports based on the example in the link.
Once this info is gathered, the next step is to create a popup with the COM port name. For this I came across an example using the plyer library for python which is dead-simple.
When you run python code, by default, the command window is always visible, so I tried a few things to hide it. Firstly, you should be able to just use pythonw.exe instead of python to run the code and it should hide the window. For some reason, this didn’t always work. The next thing I tried was using the win32 library in python. This grabs the foreground window and hides it. Since the foreground window is likely this python script, it works fine. Running it sometimes takes a faction of a second for it to hide the window so sometimes you see it flash a command window.
The final step is to have this app start when you turn on the computer. Some folks said you could just put your python file into the windows startup folder, but this never worked for me. Instead, I keep the python script in my installations folder (where I keep all my useful apps) and I wrote a batch script to run the python code. I saved the batch script into my startup folder and rebooted. It works great and doesn’t use many resources at all!
Get my python code and batch script here. If you use it, let me know in a comment.
Now, if you use linux or mac, I recommend you check out usb-ser-mon which has some of the same functionality of detecting plugged-in devices. Then you can use the same plyer code to generate a popup from what I understand.