Is it possible to check the both signals simultaneously and read the time when both the signals are becoming non zero??
Please tell me what should I do if I want to do this project with as minimum external componenets as possible. What are the componenets I require and how to proceed further.
Take a look at this AVR application note for how to perform zero cross detection without additional hardware if you can get your sine waves reduced to a safe current for the digital inputs.http://www.atmel.com/Images/Atmel-2508-Zero-Cross-Detector_ApplicationNote_AVR182.pdf
this AVR application is using ATmega 163, can I use Atmega 328P for same purpose?
What do you mean by the same time? If two interrupts happen simultaneously one ISR will have to wait until the other is finished before running
Now please tell me how to use ISRs to measure time differences between edges of two different signals.
As per the zero cross detector AVR application document, signals from ac main is directly given to PD2/EXT INT0 pin, but previously you told me to rectify and clip the voltage within 0-5V only as beyond that limit pins may get damaged. Which should I follow?
As per the zero cross detector AVR application document,
lack of isolation of the high voltage from the board
The other considerations with this method are the lack of isolation of the high voltage from the board, the potential for noise on the high resistance input, and some slight timing issues for zero cross.
I am not really aware of coding part of arduino and I am learning this part, so it will be helpful if I get some help related to this,