automatic light intensity dimmer function using fuzzy logic.
The Arduino is a low-cost DAQ hardware, the variant used is the Arduino Uno, which runs on an Atmel328, 5 Volt chip running at 16MHz. Before collecting data, there are two things important— sample rate and resolution. There's also a problem of system sensitivity. The analog to digital converters (ADC) on the Arduino operates at 10 bit resolution. The bits of resolution implies 2 10 = 1024 steps or divisions (0 to 1023), of the reference voltage. For an Arduino, the reference voltage is usually 5 volts.
MATLAB is one of the most productive numerical computing software environment for engineers available. It can be used to acquire live and measured data. So, we match the 0 to 5 volts LDR-Arduino operation range to get maximum resolution and sensitivity of the d.c lamp’s brightness to the LDR sensed values.
In this project, we developed a digital PWM controlled d.c lamp with increased sensitivity to light intensity of the nearest environment compared to similar analog implementations available. We have also used Arduino as our Data Acquisition Hardware and MATLAB/Simulink as the Data Acquisition Control Software. This setup has many advantages. The approach employed in this project is follows the steps described below:
- Continuously sense the ambient light intensity using the Light Dependent Resistor, or any appropriate Photo Resistor
- Arduino DAQ Hardware receives this signal and samples it in the 0V to 5V range, corresponding to low light intensity and high intensity values respectively
- The DAQ Software, which is MATLAB/Simulink acquires this sensed signal and using digital mathematical fuzzy functions, increase the sensitivity of the read analog voltage value, using ADC sampling and quantization theory.
- Send, based on the digital control function running through MATLAB, appropriately sampled PWM digital value, between 0 and 1 to the positive terminal of the DC-Lamp, to either reduce or increase the lamp’s brightness respectively.