Development of Android based Street Light Controller

Sir, i didn't simulate in proteus. I am using my internship kit, it uses AT89C52. Now i am using AT89S52 instead of AT89C52. The problem is that, when i insert c52(without code) into kit, there is supply.But when i insert s52(with code or without code) into kit, for some seconds supply is there, after that there is a sound like "tip", then there is no supply. one of my sir saying that "Watch Dog Timer" is effecting . I don't know what it is and is there any problem with this. One more thing is that what is the use of "IE= 0x91" command i.e. why you initializing external interrupt.(in your project "GSM Based Notice Board", line no:132 in main function). i am unable to attach files, it shows web page not available(after 43% uploading of files.).

I am using my internship kit, it uses AT89C52.

satish@iiit

Can you give a link to info about it.

The problem is that, when i insert c52(without code) into kit, there is supply.But when i insert s52(with code or without code) into kit, for some seconds supply is there, after that there is a sound like "tip", then there is no supply.

satish@iiit

The watchdog is off unless you turn it on , in any case it should not
cause this problem.
It sounds like a hardware fault.
Can you try another 89s52 ?
Try disconnecting the relays in case they are shorting something.

why you initializing external interrupt.
(in your project "GSM Based Notice Board", line no:132 in main function).

satish@iiit

I have no idea
It was probably left over from an earlier version of the code.

The GSM Based Notice Board is not really "our" project.
It was posted by a member.

I am attaching a simpler version that should do what you want.

GSM modem needs a power supply with minimum 2A peak current. make sure your supply is good enough for that. You have lot of stuff on your board which needs good amount of power like relays and modem. energizing relay coils also require current, so power supply has to be robust with atleast 2A current output.