http://www.ebay.in/itm/131170880004?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
Module Description

1. can detect the brightness of the surrounding environment and strong (and photosensitive resistance comparison, directivity is good, can sense fixed direction of the light source)
2. sensitivity adjustable (shown in blue digital potentiometer control)
3. working voltage of 3.3 V – 5 V
4. output form:
A analog voltage output
B digital switch output (0 and 1)
5. has fixed bolt hole, convenient installation Seven small board PCB
6. size: 3 cm * 1.6 cm
7. Module interface specifications (4 wire)
8. VCC external 3.3 V – 5 V voltage (can be directly and 5 V single-chip microcomputer and single chip microcomputer to 3.3 V)
9. GND external GND
10. DO small plate digital output interface (0 and 1)
11. AO small plate analog output interface

Instructions for use

1. photosensitive diode module on the environment light intensity is the most sensitive, are commonly used to test the brightness of the surrounding environment and strong, in most cases can and photosensitive resistance sensor module general, the difference is that, photosensitive diode module directivity is good, can sense fixed direction of the light source.
2. module in matt conditions or intensity of light can not reach the setting threshold, DO mouth output high level, when the outside environment light intensity than setting threshold, module D0 output low level;
3. small plate digital output D0 can be directly connected with the single chip microcomputer, through the single chip microcomputer to detect the high and low level, thus to detect the environment light intensity change;
4. small plate digital output DO can directly drive the relay module, which can form a photoelectric switch;
5. small plate analog output AO can and our AD module is linked together, through the AD conversion, can obtain the environment light intensity more accurate numerical;

Test specifications

• Use the 51 development board and photosensitive diode module test Connection description:
• Module VCC joint development board VCC
• Module GND joint development board GND
• make up VCC and GND, modules, the power indicator will light
• Will be placed in a light source module, control board blue potentiometer, until the plate of the switch on the light, and then hand cover photo diode, module switch lamp will be destroyed. Hand open, switch lamp farewell to light condition. This phenomenon is that light can trigger module, so that the switch lamp light.
• Additional material inside with a 51 procedures, used to detect photosensitive diode module digital interface D0 height level
• Module VCC joint development board VCC
• Module GND joint development board GND
• Module D0 joint development board P0.1
• SCM: STC89C52
• Serial port to send data baud rate: 9600
• light source module, serial port to send the trigger continuously, and at the same time switch indicator;
• No light trigger module, serial port to send data not, at the same time switch lamp out.