Introduction to Ambient Light Sensor
Lighting is an integral part of a building, be it commercial, official or personal space. Today’s generation gives predominant importance to energy conservation systems during building construction. Similarly in a greenhouse environment, lighting system is crucial for plant’s growth. It is important to measure the light parameters in order to ascertain conditions. An ambient light sensor is used to detect light and measure its brightness just the way a human eye would. The sensor helps measure brightness in a scale according to the ambient light conditions. Today these kind of sensors are being used in various applications ranging from headlights of cars to PDAs to smart lighting solutions.
Today I am going to introduce you to SparkFun Ambient Light Sensor Breakout – TEMT6000, an ambient light sensor designed by SparkFun.
Description: TEMT6000 is a silicon NPN epitaxial planar phototransistor in a miniature transparent mold for surface mounting onto a printed circuit board. The device is sensitive to the visible spectrum.
- Adapted to human eye responsivity
- Wide angle of half sensitivity ϕ = ± 60°
- SMD style package on PCB technology
- Suitable for IR reflow soldering
- Lead free component
- Component in accordance to RoHS 2002/95/EC and WEEE 2002/96/EC
Ambient light sensor for display backlight dimming in:
- Mobile phones
- Notebook computers
- Cameras Dashboard
Here’s the Circuit diagram for TEMT6000
It uses +5Volt VCC, a 3.3 Volt Analog input and has a Ground pin. The higher the light intensity the higher the analog voltage on the input signal pin.
Sparkfun sensor works on the principle of photodiode. The current flowing through the photo diode is proportional to the light falling on the device. Which is converted to voltage with proper circuit and calibrated. Photo transistor also employed for these light sensors, the advantage is that it doesn’t requires amplification.