Copyright © February 2005,
PixController Inc., All rights reserved.
|At the heart of
any motion sensing controller board is the motion sensor
electronics. At PixController Inc. we take this very
seriously. Our motion sensor electronics are of a unique
design unlike completive boards which copy "public
domain" designs from the internet. With our
design you will not get as many false triggers like you do
with other systems, and our PIR electronics will shut
down when the board battery gets low where other
systems will take false photo after false photo!
Our PIR design has a very fast recovery after a PIR trigger
too! This enables our board to give you instant feed back
when using Walk-Test mode to indicate the PIR detection
area. Our competitors make you wait 10- 20 seconds between
PIR triggers, making Walk-Test mode on their system an
sensor can detect the target in any vector of travel
(say up and down target movement), which is very important
if you plan to mount your sensor in an elevated position for
say security reasons. Other competitive PIR detection
electronics will fail in this case. Knowing your
system is working in the field all the time is what we
strive for, and is what you have come to expect from our
high quality products!
the PIR Lens
The PIR lens should be mounted to the case you have your board mounted in.
The lens should be centered over the PIR Sensor and be 0.65" from the
top. Make sure you mount the lens with the "ridges" faces
towards the PIR sensor. Do not scratch the lens on either side. Also, do not
mount any glass over top of the PIR lens. Glass will not let
infrared heat to pass through to trigger your PIR sensor. To mount the
lens to your case drill a 1" hole centered about the PIR sensor. Glue
the PIR lens to the inside of the case (lens ridges pointed in, smooth
side out), and glue the lens to the case with Marine GOOP (can be
purchased at your local hardware store). Note: we do not recommend
using double sided carpet tape to secure your PIR lens.
Motion Sensors Basic Overview for Effective Use
All PixController motion
control boards use a PIR motion detection sensor. PIR stands for Passive
InfraRed, which detects warm targets in motion over ambient
background temperature. A stationary target, or a target not moving can
not be detected. The target must also have a warmer surface temperature
than the ambient background temperature in order to be detected.
The size of the target and the distance of the target from the PIR sensor
will also effect if the target can be detected or not. Smaller targets
such as birds and small mammals may not be detected especially if they are
moving fast or are at a great distance from the PIR sensor. Larger targets
such as medium size and large size mammals are easily detected within the
range of the PIR detection area (see below). However, if you increase the
the sensitivity of the PIR sensitivity POT
you can detect smaller targets, but you run the risk of a greater chance
of false triggers.
As ambient background temperatures rise to near 96ºF, the difference
between the target and ambient background temperature decreases for
warm-blooded targets. The sensitivity of the PIR sensor declines in this
instance. However, as ambient background temperature decrease the opposite
is true and the sensor PIR becomes more sensitive. Under
these conditions you can adjust the PIR
sensitivity POT to accommodate your detection range needs. The
graphics below show an example of the PIR detection area at around 69ºF.
The PixController PIR sensor is unique in that the target does not need to
be moving from right to left, or left to right. Our sensor can detect the
target in any vector of travel (say up and down target movement),
which is very important if you plan to mount your sensor in an elevated
position for say security reasons. Other competitive PIR detection
electronics will fail in this case.
The red area is the PIR detection
area in the above graphic.
Fast Re-Trigger PIR
The PixController PIR detection
electronics is unique in that is a very fast recovery after each PIR
detection trigger. Competitive PIR electronics will not be able to detect
the next detection trigger between 5- 20 seconds. This makes items such as
Walk-Test mode on their system an unusable feature. The the key is that
the PixController PIR circuit used advanced digital detection electronics,
where our competitors use older analog PIR detection electronics. Our PIR
detection electronics recovery time is only 1/2 second! This is why you
will see unique features like continuous recording as long as the target
is present in the PIR detection area for our video systems. This feature
alone is an invaluable tool for building video systems.
LE Board Mounting -
PIR Sensor Considerations
new PIR sensor will allow the board to be mounted horizontally or
vertically without needing the PIR sensor to be rotated like you see in
other board designs.
Our PIR sensor circuit is the most rugged and reliable on the market
today. Triggering occurs when a change in infrared levels is detected, as
when a warm object moves in or out of view of one of the sensor's
"eyes." Our PIR sensor design is quite resistant to false
With other boards you need to consider how you mount your board, either
vertically or horizontally. Since our board is unique you can mount it
horizontally, vertically, or upside down without the need to remove the
PIR sensor and rotate it, which can destroy your sensor if you attempt
this by yourself. This is why we chose a special PIR sensor to alleviate
this issue, and a main reason why we consider quality and our customers
first. Also, our sensor can can be mounted in elevated positions such as
from high in a tree. Since our competitors PIR sensors need the target
moving from left to right or right to left this elevated position will not
- Point the sensor away from the rising or setting sun.
In general, North or South works well, but your local site conditions
could dictate otherwise
- Keep the sensor aimed at an area that will not have
intense, direct sunlight warming all or part of the detection area.
Shadows of trees or clouds moving across a sun-warmed area can cause a
momentary temperature drop which could cause a false event to be
recorded. The warmed air rising from the ground can cause problems
- Do not place the sensor in a location
where direct, bright sunlight will fall on the sensor window.
- Tall, sun-warmed grasses or other vegetation blowing
in a breeze can be detected. Point the sensor away from dense,
sun-warmed vegetation which can trap heat.
- Even in a shaded area, keep the sensor pointed away
from dense shrubs or trees that can retain the days warmth. A warm
evergreen or other dense shrub will hold the days heat. If the air
temperature drops at night - and the still warm shrub moves in the
wind, this movement could be detected.
- If the area is known to have many small birds /
mammals, you will surely get many empty pictures, as these active,
fast animals will often leave the frame before a picture can be taken.
Orient your sensor to your target.
- Wind (moving air) can cause
false events. The moving air might be warmer or cooler than the
background. Place the sensor in an area sheltered from strong winds
when you use your PIR sensor equipped cameras in a location prone to
- Wind can also cause movement of the
tree or other object you have your sensor mounted to. Make sure to
secure your sensor to an object that will not sway in strong winds.
Trees should be a minimum of 10" in diameter.
- Make sure your equipment is fastened
securely. Movement of the equipment can be interpreted as motion by