inkha is designed to detect and interact with human subjects
inkha's field of view is approximately 60 degrees which means that human movement outside the occular fov cannot be detected
a pyroelectric infra-red sensor was scavenged from a burglar alarm and mounted to the side of the head
in inkha1 this sensor was connected but not used due to there being no easy way to interface it

for inkha2 3 yd85g mini pirs were bought from maplin which work at 6V
these were interfaced via one of the inputs on the asc16 board
as each ear sensor operates over 90 degrees, the sensing range for inkha is 90+90+60=240 degrees
the pirs in inkha2 are used to wake inkha up from sleep
when inkha2 is awake the left and right pirs cause a rapid movement to the side as if a sound had been heard