Fixed pulse application [Pulse output of STM32]
This application program uses the timer of the STM32 MCU to generate a fixed frequency pulse only when an input switch is pressed.
Pin used：PB8 Alternate output(Timer output)
Peripheral used：TIM4_CH3 Counter CLK 1kHz
This application uses CH3 of TIM4. The pin used is TIM4, the default alternate function of PB8.
The TIM4 setting sets the timer count clock to 1 kHz and counts 500 to generate a 1 Hz pulse from CH3.