Moderator: igrr
since the pins are HIGH means there is already a voltage on it ( bit is 1 )
this effectively means that the PIR must trigger a transistor ( a logic gate or just a NPN transistor)
that will "flow" the current to ground ... effectively pulling LOW the gpio pin
if you use a "normally LOW" pin (ie not "Pulled Low" ) then you just need to make sure the the output of the data pin on the sensor is 3.3v ... otherwise you need to reduce its voltage in some way. when the sensor will drive the pin , the gpio will read HIGH.