PixController - Automated Camera Control Systems

PixController LE
Copyright © February 2005, PixController Inc., All rights reserved.
Motion Sensor

Introduction

Specs

Settings

Connecting Cameras

Motion Sensor

Building Systems

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 unusable feature!

Our PIR 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!

Mounting 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.

PIR 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.

PIR Sensor Detection Area
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 detection electronics
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
Our 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 triggering.

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 work.

Camera/PIR Setup Tips

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
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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 too.
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 high winds.
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 the sensor.