InfraRed Flame Sensor for NXT
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Limited Stock        NIRFL    NXT InfraRed Flame Sensor    $39.00            .

Find a candle or the sun.

The infrared Flame sensor detects Infrared light, which is also called radiated heat. The heat may be produced by a candle, the sun, or an incandescent lamp. This sensor sends a number to your NXT computer indicating how much heat it is measuring. Your program can make decisions based on this number. Your robot can find a candle or light bulb and go to it. This sensor is compatible with the Lego Mindstorms NXT Robotic System.



The easiest way to program the sensor is to download the custom G-code block

The block has scaled, raw, and boolean outputs.  The example below displays the scaled value and turns on the lamp if the value is greater than the compare value.

If you are using another programming language, you program the sensor as a powered 9 volt legacy sensor.  The raw output is around 1020 when no light is detected, and around 370 when strong light is detected.


The IR flame sensor detects any form of Infrared light. The sensor may also detect:

•  Incandescent lamps.

•  Direct or reflected sunlight.

•  Hot objects like electric heaters.

•  Infrared remote control devices.

A room with a lot of sunlight or incandescent lamps may flood the sensor with IR radiation, making it difficult to distinguish a candle from the background light.  You can reduce the effect of background light by using a view restrictor.  This limits the sensor's view to a narrow cone, like blinders on a horse.  The sensor comes with two view restrictors for medium and narrow field of vision.


The sensor also has a sensitivity control which allows you to reduce the sensitivity when the sensor is being flooded with background light.  This also reduces sensitivity to the candle flame.  The sensor will alway work best in a room that has only flourescent lights and no windows.



Technical Description

The sensing element is a phototransistor with peak sensitivity in the near infrared. It is packaged in plastic that blocks visible light. The sensitivity control adjusts the maximum current through the phototransistor. You can adjust the current to compensate for a “bright” environment that would otherwise saturate the transistor.