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Adafruit GA1A12S202 Log-Scale Analog Light Sensor

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Quoting product code: N53DQ


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About this product


  • Output voltage increases with light on the sensor
  • Logarithmic response not only gives more sensitivity in low light, its also almost impossible to ""max-out"" the sensor
  • Dynamic range of 3 to 55,000 Lux

Product overview

• Output voltage increases with light on the sensor• Logarithmic response not only gives more sensitivity in low light, its also almost impossible to ""max-out"" the sensor• Dynamic range of 3 to 55,000 Lux• Use indoors and outdoors without needing to recalibrate!

Upgrade a project that uses a photocell with the GA1A12S202 analogue light sensor. Like a CdS photo-cell, the sensor does not require a microcontroller, the analog voltage output increases with the amount of light shining on the sensor face. This sensor has a lot of improvements that make it better for nearly any project. The biggest improvement over plain photocells is a true log-lin relationship with light levels. Most light sensors have a linear relationship with light levels, which means that they're not very sensitive to changes in darkened areas and 'max' out very easily when there's a lot of light. Sometimes you can tweak a resistor to make them better in dark or bright light but its hard to get good performance at both ends. This sensor is logarithmic over a large dynamic range of 3 to 55,000 Lux, so it has a lot of sensitivity at low light levels but is also nearly impossible to ""max out"" so you can use it indoors or outdoors without changing code or calibration. Since the sensor is fabricated on a chip, there are also fewer manufacturing variations, so you won't have to calibrate the sensor from one board to another. Using the sensor is easy as pie: connect the Vin to 2.3-6VDC, Gnd to ground and measure the analogue output on OUT. It will range up to 3V (at extremely bright outdoor sunlight). On an Arduino, just use analogRead() with the OUT pin connected to an analogue pin.

On this breakout there’s a 68KO resistor from OUT to ground to turn the current into a voltage.

how do i make it work:(

Asked by: harvs
Unfortunately, we can't provide advice on how to integrate this into a project.
Answered by: Dominic
Date published: 2017-11-03

Can I use this with conductive thread? 

Asked by: Rosel
use a non conductive thread its safer :)
Answered by: harvs
Date published: 2017-11-02

What are the overall dimensions of the unit [mm please] - height / width / thickness ?
Asked by: Ian
Specifications: Power with 2.3-6V Onboard 68K load resistor for max 3V analog output 0.2 grams 0.4" x 0.5" x 0.06" (10mm x 13mm x 1.5mm) 0.1" (2.5mm) mounting hole
Answered by: PC
Date published: 2016-03-25
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