Hi everyone. I am thinking of making a robot which uses 3 PIR sensors RAPIDONLINE 61-1516 to detect and track objects emitting thermal energy.Do you think using a 9V battery this would
work?in terms of power consumption and stuff like,considering i would be using 3 of these PIRs and other sensors like microphone,buzzer etc.
9V batteries are typically a
9V batteries are typically a poor choice for robots, since they can’t deliver much current and quickly run dry.
Since you’ve mentioned using a PICAXE, why don’t you use 4 x AA batteries instead? 4.8-6V will run both the PICAXE and PIR sensors, plus the robot will go much further on a fresh charge.
thanks. i do have a 6x AA
thanks. i do have a 6x AA battery holder, i could use that and a regulator couldnt i?do you know if i could connect the PIR sensors directly to the PICAXE like V+,GND and the other one to the PICAXE input pins or there is some special circuitry required?
6 x AA + regulator will be
6 x AA + regulator will be fine, and those PIR units are designed to be connected directly to a digital input pin/+5V/Ground, so that’s all good.
thanks a lot 
thanks a lot
you know these don’t detect heat, right?
The PIR you are talking about is a motion detector. It is non-directional as well. It won’t work when your robot is moving. I don’t think this is the direction to go. Maybe start with the “start here” robot.
ive seen on some websites
ive seen on some websites where they say they do detect heat emmitting objects e.g. http://www.stopbox.co.uk/s.nl/ctype.KB/it.I/id.248/KB.65/.f
Although PIR sensors do work
Although PIR sensors do work by detecting emitted IR from warm objects, the output from the sensor will only tell you if what the sensor sees is changing - static objects in front of the sensor are not reported, only moving objects.
It could work…
But your robot would have to be stationary, you would only be able to calculate the moving object to be in 5 large areas
1 O
2 O s1 – 3 O
4 O s2 [ ] s3 5 O
The dashes and brackets are the sensors and the Os are the fields of view
the “2 O” field is a cross between s1 and s2’s fields of view
the “1 O” field is only in s1’s feild of veiw … and so on
i see.what sort of output do
i see.what sort of output do you get from the PIR though? as in do you get like a 1 when a change is detected and a 0 if there isnt any change?thanks
Normally there’s a high/low
Normally there’s a high/low pulse when the PIR circuit decides it has detected something moving. Although they’re just called PIRs, there’s actually a lot of circuitry inside the little shell that analyses the PIR sensor and generates the output signal.
thanks 
thanks