Photodiode Sensor Module, 4 Pins Photodiode Sensor Module, 5mm Photodiode Module, for Digital Light Brightness Detection, Photosensitive Sensor Module for Arduino(10PCS)

My project, a nightlight application, requires that the photodiode module accurately measure the ambient light when the illuminating light (an LED array) is turned OFF under program control. As the photo of the 'scope trace shows, the ON and OFF response times of the photodiode module are about 3 ms, which implies that I can turn the LEDs OFF, every 30 minutes or so, check the ambient light level, and then, if the ambient light level is still below the set threshold, turn the LEDs back ON without a noticeable "blink" to the human eye. If the ambient light level is above a set threshold, then the LEDs will remain OFF.

I've been testing (playing with) the photodiode sensor module and it's rather simple to use. There are 4 pins, 2 for ground and power. Then there is a digital pin that just indicates if light is present or not (high and low). And lastly there is an analog pin that provides the level of ambient light seen by the sensor. I've just been using the digital pin in a quick project where I connected a module to a relay in order to turn on a radio when the lights go out. The next project will be to add a module to my Arduino robot car to follow a light. There are 10 modules in the package so I can use them in many projects. This is a good way to learn more about light and how it can interact with electronics. The price point for the package is quite reasonable. I'm enjoying this set of modules.

This little board has a photodiode and it is properly reverse biased and provides a pullup resistor and comparator circuit with on board LEDs to indicate power and comparator output as well. The 4 pins include power , ground, comparator out and analog signal. I'm not sure of the photodiode characteristics but I assume it has a visible light spectral sensitivity. During the daytime it responded to indirect sunlight coming in through the window. I wanted to limit the spectral response to IR so I replaced the diode with a 940 nm IR photodiode on one of them. That was easy because the photodiode is a leaded discrete device ( not surface mount). The pot can be used to set a logic threshold for the comparator. Again pretty handy and I think 10 boards in the package each in its own bag.Note: the comparator output appears to directly sink the "DATA" LED current so when there is light on the photodiode, the LED is ON but the DATA level is LOW. DATA signal tracks the Analog voltage out. ( if I remember right...)

As the title states, they work, but the photo diode analog signal is rather unstable and difficult to get any decent real reading out of. At least on a 5 volt supply. Will try 3.3 and see if it improves. The digital out is what it is. It’s either on, or off, depending on light conditions.

The media could not be loaded. Nicely individual packaged sensors.2 signal outputs, 1 analog and 1 digital.In the digital output is either high or low.The sensor has two LED's, one indicates the device is powered up. The other LED follows the digital output.Easy to integrate with many projects, 4 pin connector. Two for power, one analog and one digital output.

I wish there was more information about these. The photo-diode responds directionally.