Measure LDR Light with Microcontroller - 10bit Resolution

Click For Summary

Discussion Overview

The discussion revolves around measuring light intensity using a microcontroller with 10-bit resolution, specifically focusing on converting the voltage or digital output to Lux readings. Participants explore different methods and tools for achieving accurate measurements, including simulations and circuit design considerations.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested, Experimental/applied

Main Points Raised

  • One participant inquires about converting the microcontroller's output to Lux readings and references a specific example for guidance.
  • Another participant suggests using a simulation software (Proteus) to find the relationship between voltage and Lux, noting that they have measured voltage and obtained a curve.
  • A participant questions whether finding the equation of the curve would allow for determining Lux values from voltage readings.
  • Some participants propose using a transimpedance amplifier instead of a voltage divider, though the benefits of this approach are not fully explored.
  • One participant expresses uncertainty about the transimpedance amplifier, noting they have not studied it yet and seeks clarification on its advantages over a voltage divider.

Areas of Agreement / Disagreement

There is no consensus on the best method for measuring light intensity, as participants propose different approaches and tools, and some express uncertainty about specific concepts.

Contextual Notes

Participants have not fully resolved the relationship between voltage and Lux readings, and there are missing assumptions regarding the circuit design and the characteristics of the transimpedance amplifier.

Who May Find This Useful

This discussion may be useful for individuals interested in microcontroller applications, light measurement techniques, and circuit design involving amplifiers.

TheRedDevil18
Messages
406
Reaction score
2
I have a micro-controller with 10 bit resolution. How can I convert the voltage or digital output of the microcontroller to a Lux reading ?
 
Engineering news on Phys.org
Jony130 said:
See the example here
http://elm-chan.org/works/lux/report.html

I don't have a lux meter. I noticed proteus which is the software I use for simulation has one. What if I used that to find the relationship ?

I used a circuit like this and measured the voltage
luxMeasure.PNG


This is the curve I got
Curve.PNG


So if I find the equation of this curve, then given a voltage I can get the LUX value ?
 
Try to use a transimpedance Amplifier instead of voltage divider.
 
Jony130 said:
Try to use a transimpedance Amplifier instead of voltage divider.

What would be the benefit of using a transimpedance amplifier over the voltage divider ?, From what I've read, it converts current to voltage. I haven't studied this type of amplifier yet
 

Similar threads

Selective Incident Headlight Intensity Measurement
  • · Replies 3 ·
Replies
3
Views
2K
Convert Lux to RGB: 4 Values to RGB/Hex Color
  • · Replies 11 ·
Replies
11
Views
4K
Deciding batteries for my circuit
  • · Replies 3 ·
Replies
3
Views
2K
Magnetic encoder signal processing
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Lux-meter, candelas or lux, measuring nits in practice
  • · Replies 2 ·
Replies
2
Views
5K
Help intagrating hertzmeter into analog linear power supply
  • · Replies 10 ·
Replies
10
Views
2K
Converting Lux to Watt for Measuring Light Power
  • · Replies 3 ·
Replies
3
Views
4K
Why does my sensor show "gaps" every 16 units of resolution?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Lux & Lumens -- how do they work?
  • · Replies 34 ·
2
Replies
34
Views
5K
High voltage voltage controlled linear variable resistor
  • · Replies 2 ·
Replies
2
Views
4K