analogue reading problem?

[Elimathew]

Guyz im making a colour sensor,here ive used three leds red green and blue and photoresistor as sensor each led would blink for 50ms.now i wanted know how should i store the analog value in micro controller(At89s52).and compare the readings,im using C language and programming using keil

 

[FvM]

AT89C52 doesn't provide an internal ADC to read analog values, you have to select a suitable chip and interface it to the processor. Depends on which are available to you. Good old ADC080x is often used for basic projects like yours, but many other ADC types have been developed in the last decades.

 

[Easyrider83]

I thing the best way is to use SPI ADC because this interface very easy to realize by software.