PIR output the same all the time.

I found a PIR(i think) sensor and a ir-led in an old toy. I tinkered a bit but keep ending up with ~1018 as input. even if the led is on/off/my hand is close/far away.
the PIR looks like this. http://cognoscis.files.wordpress.com/2008/10/tsop11.jpg
i read this to know where to connect the pins. http://cognoscis.com/tag/ir/
the code is here: http://pastie.org/954099
the only time the input changed was when i plugged some other cable to something else. but it was only lowered to ~1015.

can someone point me in the right direction please?

Is that really a PIR, or an IR receiver/demodulator?
What happens when you point an IR remote at it?

FYI, a PIR is bolometer-type sensor, for longer wavelength IR, whereas an IR remote and receiver use much shorter (though still invisible) wavelengths.

from the datasheet:
"TSOP17..KA1 is the standard IR remote control receiver series, support-
ing all major transmission codes."

seems like the second option you said.

wohoo
i swapped analogRead for pulseIn and now it works like a charm.
code here: http://pastie.org/984476