Photodiode to measure blue light intensity

Hi, I am trying to find a way to measure the amount of blue light (380nm-500nm) from various light sources. I am wondering if there is a way to use the photodiode to do this.

I'm not entirely sure if the photodiode measures the intensity of white light only or does it measure the intensity of any single wavelength of light.

Is there a way for me to do this using TSL257 photodiode and arduino uno.


TSL257 has the following light wave sensitivity.

If you want to detect only a specific band, please use with corresponding color filter.

@hxgxti, your topic has been moved to a more suitable location on the forum.

Theres no reason you cant use that photodiode; however if you are comparing light intensities from different wavelength sources you will need to calibrate to allow for the changing sensitivity.

You may also need a filter or prism if you want to select for a particular waveband.

An LED can be used as a photodiode, and it will detect only light in roughly the same wavelength range as the emission spectrum (the detection maximum is shifted 25 to 50 nm to the blue of the emission maximum). See How to Use LEDs to Detect Light - Make:

So, no bandpass filter required.

the amount of blue light (380nm-500nm) from various light sources.

Be more specific. The LED photocurrent is proportional to the total intensity, integrated over the LED detection bandwidth.

A tept4400 ambient light sensor has a peak sensiticity at about 570nm with a range from about 440nm to 800nm
You could use that and put a blue filter in front of it?

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