counting ADC light sensor values

hello, i am new to micro controller programming and in need of help. i have managed to interface a light sensor to a micro controller (atmega 32a) and can read the value i.e. (1023) as per the set prescale. however i intended to achieve a single decimal value as the result. in this case (1) every time the sensor is exposed to light and successively perform an incremented tally as lights go on and off around the sensor ( i am using a LDR for this). i am currently having problem getting my micro controller to do this. i have searched all over the internet but no seems to assist me on this... please any insight on how to achieve this will be much appreciated. i know its a simple thing,HELP :frowning:

basically just a means of making my micro controller count the number of times light falls on the LDR

Take a look at the state change detection example in the IDE examples (File, Examples, 02.Digital).