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Topic: arduino and photodiode BPW34 (Read 3426 times) previous topic - next topic


Nov 16, 2015, 10:37 am Last Edit: Nov 16, 2015, 12:00 pm by varjith007
Hi Iam varjith, i would like to do a small project , i wonna automatically adjust the light intensity in a room using the windows and lights in the system. like if the light intensity in the room is less automatically windows will open and even after windows are opened if the light intensity is less. then automatically the light is switched on. for this i am going to use the BPW34 photodiode. but i dont know how much voltage the sensor produce for a perticular intensity, and i too dont know how to connect the sensor with the arduino becuase as it produce variable voltage( means for the coding section)

here is a chart but, is there any predefined charts about how much voltage will it produce for a perticular light intensity


Your document states Voltage Out = LUX / 1333.
Do you understand that formula?

Your document shows the circuit you need to build.
Can you build that circuit?

1,000 Lux is an overcast day outside.
At 1,000 Lux, the circuit should generate about 1 Volt
across the resistor and into the Arduino A0 Analog Input.

The graph states, "Vr = 5 Volts".
So, I am assuming that is DVDD.

The PhotoDiode is Polarity Sensitive!
You are dealing with microamps, so noise will be an issue.

There are three connections to your circuit
Connect +5 Volts at the top
Connect Arduino A0 Analog Input to the middle
Connect ground at the bottom
Can you make these connections?

Maybe, a shielded cable?

If you can get that working,
and the Input Voltage is too low, at your lighting levels
then you may need to build a Non-Inverting Op-Amp circuit, too.

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