Howdy,
Recently one of the members of the forum mentioned that not all LEDs in a given "lot" have the same luminosity/brightness.
I have noted that fact in some of the bunches that I have bought - most bright, but some less bright.
Also based on the comments of another member, I thought I would build a little "light meter" to measure the relative luminosity of my LEDs so as to classify them into similar levels of brightness.
So I set up something like this:
5V
|
photoresistor (varies with brightness between 150Ω and 18kΩ)
|
connection to Arduino (analog pin)
|
10K resistor
|
Ground
On the Arduino I programmed a few simple lines taking the voltage input, converting it to a range between 0-100 and then displaying it on a 3 digit 7 segment LED display.
It seems to work just fine.
I'll probably upgrade to a Light to Voltage converter, but I'll buy one next time I order some other parts.
My questions for the group:
1. Do you know of any "standard" LEDs that I could use to calibrate my rudimentary "meter"?
(I understand that I don't really measure lumens, but would like to have some "standards" to use between measurement runs)
2. Are there other ways of calibrating/linearizing my rudimentary device?
I thank you in advance!
Recently one of the members of the forum mentioned that not all LEDs in a given "lot" have the same luminosity/brightness.
I have noted that fact in some of the bunches that I have bought - most bright, but some less bright.
Also based on the comments of another member, I thought I would build a little "light meter" to measure the relative luminosity of my LEDs so as to classify them into similar levels of brightness.
So I set up something like this:
5V
|
photoresistor (varies with brightness between 150Ω and 18kΩ)
|
connection to Arduino (analog pin)
|
10K resistor
|
Ground
On the Arduino I programmed a few simple lines taking the voltage input, converting it to a range between 0-100 and then displaying it on a 3 digit 7 segment LED display.
It seems to work just fine.
I'll probably upgrade to a Light to Voltage converter, but I'll buy one next time I order some other parts.
My questions for the group:
1. Do you know of any "standard" LEDs that I could use to calibrate my rudimentary "meter"?
(I understand that I don't really measure lumens, but would like to have some "standards" to use between measurement runs)
2. Are there other ways of calibrating/linearizing my rudimentary device?
I thank you in advance!