GSM based Automatic meter reading is the technology of automatically collecting data from energy meter and transferring that data to a central database for billing and/or analyzing. The Transmitter circuit is connected to the meter which counts the pulses from it and displays it over the LCD display. The transmitter circuit containing a GSM modem for data transforming, which transforms the meter reading after each 10 pulses to a particular number through SMS.
An additional advanced service is also available, which includes the software operating on the computer. This software shows the updated reading. User has to put the unit rate and date of billing, and then this software automatically calculates the bill and also print it if printer is connected to computer.
In this GSM based Automatic meter reading, a led is connected in parallel to the ‘cal’ led of meter reading. This led is paired with a LDR, which acts as an Optocoupler. the output of LDR is connected to the base of NPN transistor and the collector output of transistor is connected to the pin P1.0 of micro-controller. So at each blink of led of meter reading, a signal is passed to the micro-controller to count the pulses of meter reading. Then micro-controller updates the reading and displayed it over LCD and also saves to the EEPROM. The LCD and EEPROM are connected to port 0 of micro-controller. For transferring the data a GSM modem is used, which sends SMS to the particular mobile number defined. The micro-controller is programmed to send the SMS after every 10 pulses of meter reading. The MAX232 is used to interfacing GSM modem, there is another GSM modem is also available which doesn’t required MAX232, it can directly connected to micro-controller