prepaid energy meters

hello sir,
i'm doing project on prepaid energy metrs and i want the info. regarding the type of energy meter that we are using and how the data is sent to the microcontroller.

you can make use of electronics energy meter being used these days... similar to this one..

or you can use an energy meter of model ADE7757.

For card reader.. use this circuit...

thankQ sir.

sir,
how the 2x16 L.C.D. can be interfaced with the microcontroller that we are connecting in the prepaid energy meters. :-)

read the LCD tutorial.. visit the tutorial link in the top navigation. if you get any doubt ask anytime..

Thankq sir,
as per the circuit dia. of the prepaid energy meter i want to know the working of the card reader when the prepaid card is inserted and how the data is transfered to the AT89S52. :mad

as you can see in the circuit diagram above.. card reader is nothing but an I2C EEPROM... so the data is transferred using I2C protocol.

thanks,
The EEPROM(smart card ) pins 6 and 5 are connected to 11 and 12 pins of the microcontroller and pins 1,2,3,4,7 are connected to Gnd. and 8 to +5v supply
if it is so,what are the commands used for programming the card for the recharge amount. please explain me sir.

you can program it separately.. like use EEPROM programmer or.. make a small Prepaid smart card recharger its simple.. just you need to write into the memory.

thank you sir,
so, what is to be done to make the prepaid smart card recharger? and how can I be able to recharge the card for 500rupees?
please sent me a sticky tape sir.