3. Hardware Development of Prepaid Energy Meter
The hardware architecture of Microcontroller based digital prepaid energy meter is shown in the Fig. 3.
The energy consumption is being calculated using the energy meter IC and Microcontroller (ATmega32). In order to
prevent unauthorized connection, a tampering detection unit is present in the Energy Meter IC.
The Microcontroller based digital prepaid energy meter system can be divided into eight parts as Voltage
sensor, Current sensor, Energy Meter IC, Microcontroller, Smart Card and its Communication with Server Terminal,
Relay Control Unit, Display Unit and Power Supply Unit. In the following circuit diagram, Vcc represents the
positive supply and Gnd represents ground. The hardware description of eight parts is separately introduced as
follows