Kc868 Read Pwm input

[huntleight]

you can use free GPIOs on board, define with PWM , try to use it.

I use PCF8574 to access digital input/output ports. Because pinmode(2,OUTPUT); and in loop function digitalWrite(2,LOW or HIGH) does not work . Same goes for input codes.

So
Q1) Can i use digital input ports for PWM? If yes how can i define those pins ?
Q2) If you said no Q1 so which pins is free GPIO and how can i use it? I use serial port pins so i cannot use that pins.