Module
used to transmit data wirelessly between these two
ends by using the short message facilities of the GSM, if we
use a GSM mobile phone for this purpose, then we have to
understand the Attention command to send or receive message
through this phone and the mobile, which is used must support
this command. Other component of this section is MAX232 IC
for the level conversion of voltages. We use it for the serial
communication between the server end pc and the GSM
module. This section is interconnected with the controlling
circuitry and the power supply circuitry.