Hi everyone...

I want to build a light regulating circuit. I plan to use LDRs as the sensor for this project, then ATmega8535, and some lamps or LEDs. Besides that, I also plan to use principle of pulse-width modulation to maintain a constant light level with a varying ambient level.

Honestly I am new here and lack of experiences. Anyone can help me how to start my project?? Suggestion, references, links, or anything that can help me...

 

Explain what exactly the circuit has to do. Just turn on some lamps when it's dark outside? Then a uC would be overkill.

 

...maintain a constant light level with a varying ambient level.

My light switches all do exactly that; maintain a level (albeit just on or off) regardless of ambient.

As noted, you need to be more precise. If you want the controlled level to vary WITH ambient - for instance to dim somewhat when ambient light goes down, you have the problem of the control responding to itself - positive feedback. Perhaps you want the lights to vary OPPOSITE ambient - to get brighter when the sun goes down, for instance.

 

ATmega Control DC Lamp intensity with LDR Sensor

LDR and resistor voltage divider.
If light levels high the resistance LDR low, adc voltage rises, the microcontroller increasing PWM duty cycle at OCR pin, mosfet more connected, caused average voltage the lights to be higher so the light bulb becomes brighter.

 

If I want to control 220 Volt AC lamp, what will I need ? Please tell tell me the complete connection from micro-controller output to the lamp..

Thank You....

 

My light switches all do exactly that; maintain a level (albeit just on or off) regardless of ambient.

As noted, you need to be more precise. If you want the controlled level to vary WITH ambient - for instance to dim somewhat when ambient light goes down, you have the problem of the control responding to itself - positive feedback. Perhaps you want the lights to vary OPPOSITE ambient - to get brighter when the sun goes down, for instance.

Yes, that is exactly what I mean. Now, what do I need If I want to control/vary the intensity of AC lamps? I mean the dimmer circuit from MUC to the lamp?

 

If you want to do the practice for what Mcu can do, it's ok to do the job of ac lamp adjustment.

If you just want to adjust the ac lamp, the you can use TRIAC to do the job is easier.

http://www.epanorama.net/documents/lights/lightdimmer.html#120v

 

If you want to do the practice for what Mcu can do, it's ok to do the job of ac lamp adjustment.

If you just want to adjust the ac lamp, the you can use TRIAC to do the job is easier.

Thanks for your help. Actually I need the circuit starting from the microcontroller up to the AC lamp (220V). Can you give me the clearer one?