Mims reasoned that since LEDs take in ....
Is this the same person who suggested using a 320M resistor in the feedback of an op amp?
I think his credibility is a bit blown by that.
No it is not, but I think you already knew that
So I looked at the book Atmospheric Monitoring with Arduino on Amazon and in the preview section I came across this diagram (attached).
Any one who thinks that is the way to connect an LED to an arduino without damaging the arduino knows absolutely nothing about arduinos and electronics.
I agree with that. He's probably using old diagrams...A shame actually, but it is the first edition of the book. You can probably score some points with them pointing that out in your charismatic ways...
As this book according to Amazon has not been released how did you get a copy?
Maybe you are looking in the wrong place. Here
, for you. I know how you love links I send you
Thanks for the link, but have you got any idea how expensive these sensors are?
Now do you actually think that can be replaced by an LED?
I hope so!
LEDs detect photons by creating electron hole pairs in the intrinsic region of a PN junction. These then get swept up by the potential barrier on each side of the intrinsic region and that represents a current.
In order to create the electron hole pair the photon energy E which is hv (h = planks constant v = electromagnetic frequency) has to be greater than the gap between the valance band and the conduction band in the material of the junction. However, this is only the minimum energy, so while an LED will react to light at the same frequency that it emits and not to lower frequencies, it will also generate a photo current for photons of higher energy / frequency.
I ask again how meaningful will measurements from an LED be?
Well good luck.
Think out of the box I would say. wouldn't it be cool if it where to work?
I've got a link
for you... These people use a led for taking scientific measurement...
With kind regards,