SparkFun Forums

[LetSmokeOut]

Hello. A friend and I are trying to build an accurate light meter using the Arduino microprocessor in conjunction with the GDM1602K LCD screen (both ordered from sparkfun). The problem is that neither of us have any experience in programming and neither of us have the time or motivation to teach ourselves. I'm wondering if perhaps there might be already written programs available which we can use. Surely we aren't the first ones to attempt to construct a light meter? We want our light meter to show the numerical measurement of ambient lux (just like the handheld light meters used by the professionals do). Can anyone please link or copy and paste the code necessary for us to accomplish our goal? I realize the code may in part depend on the photo diode we use to detect light, but any generic code used for this application would be sufficient for starters so long as we would only need to change some values to tune in the desired accuracy. If anyone is a programmer hobbyist of sorts and would be willing to help us by writting a program from scratch that would also be something very much appreciated.

Please help in any way you can. We are very eager to finish our little fun project.

[glassfog]

http://www.sparkfun.com/products/8940 is a possible starting point. The tutorials by Roaming Drone will kickstart your project; theory and design considerations in depth, worth the read.

[LetSmokeOut]

Oh, thank you for the link! I happen to have this in my toolbox:

http://www.datasheetcatalog.org/datashe ... Xqyxtx.pdf

Do you think we could use this (see above) instead of the:

http://www.sparkfun.com/products/8940

?? They appear pretty much the same to me.

[LetSmokeOut]

We also have this (from sparkfun):

http://www.sparkfun.com/products/9088

Would this work or do we need something more sophisticated or sensitive to give us the readings we need to convert to lux?

[glassfog]

http://www.sparkfun.com/products/8940 will output a signal that you can read with an Arduino.

http://www.sparkfun.com/products/9088 is basically a photoresistor with sensitivity peak in green - 540nm.

http://www.datasheetcatalog.org/datashe ... Xqyxtx.pdf outputs a voltage proportional to the light intensity but is dependent on supply voltage to determine full scale.

What is your application? Do you have a particular spectrum or intensity range in mind?

Again, I recommended the TSL230R and the discussion by Roaming Drone as it provides the things you asked for in your original post. He provides a breadboard setup and code examples, check it out.