Infrared sensor

Other Hardware Sensors
1

I just ripped open a motion detector to see what I could salvage :D. Inside I found a photoresister (looking for these) and a nice big infrared sensor. Like this one.
I plan to mount this on my bot's conning tower. I'm hoping it will be able to detect humans/animals/machinery. All the better to see you with ]:smiley:
P.S. I have no idea how to interface with this...

2

You will have to trace the circuit on the detector and see how they treat the
signal from the sensor. Likely they just amplify it and send it to a comparator
to give yes/no output, and you can tap off of that.

OTOH, you could buy a sensor made specfically for this purpose - fairly cheap,
probably available at your nearest Radio Shack, etc. Eg, 1st picture,

http://images.search.yahoo.com/search/images?_adv_prop=image&fr=sfp&va=PIR+motion+sensor

3

My plan was to take only the sensor (three pin) out of the circuit and wire it up to my Arduino. I was hoping that I could just run a current through it and get some kind of signal from the third pin. A cursory search tells me that the three pins are:
1 Drain
2 Source
3 Ground

Well that's not very helpful. The reason why I don't want to use the circuit it comes with is that I want an analogue reading such as with a light dependent resistor. Am I wasting my time?

4

Usually for detect something with an IR sensor you need an IR transmitter (like the IR led in the savaged pack). If you have both the IR sensor and the IR transmitter you can couple this to create an IR beam or a proximity sensor.

5

I don't really want to have a beam break scenario, I'm going for passive detection. I just want to point it in a direction and get a general infra-red (heat) reading. So far I've wired it up as so and it seems to work:

Sorry about the quick drawing.

I'm getting a reading off the voltage divide of around 100 which goes up to 110 if I hold my hand above the sensor. This is only around a 0.05v change so I'm going to figure out how to amplify the response.

Oh, can someone please chip in if I'm heading towards frying my Arduino with my lack of knowledge.