geiger tube with stm32

[123LY321]

I'm sorry to disturb you, but I encountered some problems when using STM32 as the controller. I found that I could not enter the interrupt count normally.

I set up the drop-down mode of pull-up input along interrupt trigger mode to configure the interrupt of MCU, and connected the external interrupt pin to the board INT.I want to ask you about the voltage of the INT pin when the detector detects the seeds and the voltage of the INT pin when the detector does not count.

We look forward to your reply,thanks