Electronics Instumentation Mini-Project - LDR

[Fnixer]

Hi

I need to design a circuit using an instrumentation sensor, I decided to go with an LDR since it simple and to use a LM324 Op-Amp. My input supply is limited to 5V and under 250mA. I need to show an output proportional to the variable level being monitored, clamped to a range of 0V to 3.3V (ranging from at least 0.1V to 3.2V), with appropriate anti-aliasing filtering, I will also need to show an LED coming on when light shines on the LDR.

Any ideas of circuit help please let me know.

Thanks

 

[schmitt trigger]

What are you attempting to measure, light level? What is the maximum and minimum lux levels?
Do you know that light measurements may span ranges of 30000:1 or greater? Therefore, do you want a linear or log output?

You mention an anti-aliasing filter, so you may be thinking of using an ADC. If so, how many bits of resolution? What is the sampling rate?

The requirement of a LED turning on when the LDR receives light, at what lux level does it require to turn on or off?