How sensitive is the light sensor?

Hi all,

I am testing the embedded light sensor on the microbit. It appeared it would only detect values if I have a torch light shining very closely on the LEDs. Is this the same for everyone or am I missing some step that makes it more accurate or sensitive.

I am in a room during the day time, it’s showing 0. I would think it should at least give me some readings since it’s day time, I am not even in complete darkness.
I can get some readings if I use a torch to shine on the LED but it would only record readings if my torch is like 30 cm from the microbit, beyond that it shows 0 light level.

thanks all,

Regards,
Mr Hope

I think I figured out, it appears to be working per design. the light sensor on microbit is not really sensitive, a photoresistor would help if you want to detect light with more accuracy.

It happened with me too and I started thinking that something is wrong with my micro:bit.
Then strangely I tested my Light Sensor sample code in the morning and voila! it worked :slight_smile:
I was earlier testing it in the night with my room light on.
Seems microbit LED light sensor is not sensitive to lights other than sun light, but I will keep checking on for different light source.
Try if it works for you in sunlight.

Hi @mrhope and @chand51,

In case you didn’t already know, the micro:bit doesn’t really have a true light sensor. It uses the LED screen to detect light, as mentioned in this video: https://youtu.be/ii0U_FMr-Z4 .

Make Magazine had an article on this approach and some of the strengths/weaknesses, including sensitivity to certain frequencies as @chand51 noted: https://makezine.com/projects/how-to-use-leds-to-detect-light/ .

Bill

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