Programming motors with joystick buttons

[incognito_NICK]

you have the right idea about using an if statment.

what you can try is something like this:

if(p1_sw_trig==1)
{
   pwm01=254;
  }
else if(p1_sw_top==1)
{
   pwm01=0;
   }
else
{
 pwm01=127;
 }