Блог

Я пытаюсь понять, какая клавиша нажата, когда она нажата, какая клавиша отпущена и когда она отпущена с помощью этого кода (Python 3.7);

 from tkinter import * import datetime  gui = Tk() gui.geometry("500x200 400 400") gui.resizable(0, 0) gui.title("Key Press amp; Release Control On Raspberr Pi")  def end_app(*args):  gui.destroy()  def key_press_control(event):  print("Pressed Key : -"   event.keysym   "- ", datetime.datetime.now())   def key_release_control(event):  print(50*" "   "Released Key : -"   event.keysym   "- ", datetime.datetime.now())  gui.bind("lt;Escapegt;", end_app) gui.bind("lt;KeyPressgt;", key_press_control) gui.bind("lt;KeyReleasegt;", key_release_control)  gui.mainloop()  

Когда я запускаю этот код на Raspberry Pi и нажимаю клавишу «r» почти одну секунду, я получаю такой результат;

Когда я запускаю этот код в Windows и нажимаю клавишу «w» почти одну секунду, я получаю такой результат;

Независимо от того, как долго она нажата, обычно мне нужно узнать, какая клавиша нажата, когда нажата информация за один раз, и аналогично, какая клавиша отпущена и когда отпущена информация за один раз.

But as you can see on these pictures, on Windows OS, key press event occurs many times but release event occur only one time (a better situation, I can control this anyway for running my other control scripts).

But on Raspberry Pi (Linux raspberrypi 5.10.63-v7 #1488 SMP Thu Nov 18 16:14:44 GMT 2021 armv7l GNU/Linux), key press and release events occur many times one after another although your finger is still on the key. With this situation I can’t control my other scripts because system detects that key is pressed and released continuously.

I’m trying to use Python native libraries and commands first, so I didn’t try other keyboard control libraries. It must work somehow, it can’t be as problematic as this.

What’m I missing?

——— 7 hours later ————

I’ve discovered that this problem on Raspberry Pi is about VNC connection. When you connect your keyboard directly to Raspberry Pi, it reacts like Windows, so no problem occurs. But when you use VNC and remote connect to Raspberr Pi, keyboard events work differantly.

I also tried pynput library, it works as the same on VNC, so problem is not solved.

Now, I need to find a good way (VNC config to solve problem) or library which works on VNC remote connection.

——— 1 hour later ————

Connect your keyboard to Raspberry Pi directly and use pynput library, key press and key release detection is as Windows, I can say normal, but it should ve tested for more time, I tried for 1-5 sc.

If you use Python native keypress and release events, they still have the same problem, after you press 1 sc. to a key, it detects one press and one release 🙁 Not solved yet.

———- 1 day later ——— I found a workaround. I keep last key release event’s time and if after a ~200 millisecond no new key release event occurs, it means that key is realy released. Now I can control my script normally on Raspberry Pi via VNC.