The circuit shown will respond to light change and act as a Latched switch. I want to add intelligence to the switch whereby I control AT WHAT LIGHT LEVEL RANGE to be ON or OFF.
This means I will connect arduino to the circuit, but I need guidance on how to do it.
In the meantime I will measure the 24 hours daylight to define the range that I will use to create the 'light switch".
You thoughts will be greatly appreciated
arishy:
In the meantime I will measure the 24 hours daylight to define the range that I will use to create the 'light switch".You thoughts will be greatly appreciated
Good idea, that sort of info will make you setup so much easier.
You won't need the LM555.
A Nano or UNO will easily do the trick.
You will need two analog inputs, one for the sensor the other for a potentiometer to set your change over level.
You would then do an if statement to check if the sensor is higher or lower than the setpoint and switch an output ON or OFF.
Some hysteresis will have to be added so that the turn ON point is say 5% higher of lower ( depending on how your sensor responds ) to the turn OFF point, this will stop any jittering if you just used one changeover point.
Tom... 
The LM555 approach was used in a very popular Light control circuit known commercially by "Photo Controls AS-10". The theory behind it; is the amount of Light detected by LDR will give varying trigger voltage from Positive to Negative; thus act as a switch. By playing with the R's and C's values around the timer I can precisely have means to control the whole circuit. The concept alone intrigues me.
But of course you are right, one should keep it simple. I will go for your approach and try to implement your tips to get stable readings.
