SMS Based Controlling Machines Using GSM Mobile and microcontroller 8051

The devices are connected to the 8051 microcontroller using relays and optocouplers. These relay are controlled through software to switch ON or OFF the device as required. For every message received to microcontroller through mobile phone in form of SMS, the controller will check for the valid and pre-define formate. If the message is correct the controller will perform the operation. microcontroller interfacing with lcd and gsm to display the msg sent to interfaced gsm

The hardware board contains microcontroller AT89c52 at the heart of the system. The microcontroller is interfaced with GSM Modem of mobile phone via MAX232 level convertor. It is used to convert RS232 voltage levels to TTL voltage levels. display the message in notice board with the help of mobile 8051 project gsm architecture based motor on and off circuit diagram

The AT89C52 is a low-power, high-performance CMOS 8-bit microcomputer with 8K bytes of Flash programmable and erasable read only memory (PEROM). The device is compatible with the industry-standard 80C51 and 80C52 instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional non-volatile memory programmer which provides a highly-flexible and cost-effective solution to many embedded control applications.A GSM modem is a wireless modem that works with a GSM wireless network. A wireless modem behaves like a dial-up modem. The main difference between them is that a dial-up modem sends and receives data through a fixed telephone line while a wireless modem sends and receives data through radio waves. Like a GSM mobile phone, a GSM modem requires a SIM card from a wireless carrier in order to operate.controlling machines using gsm mobile sms services

Generally, computers use AT commands to control modems. Reading of message from the SIM card inserted into the modem is done by sending the appropriate AT command to the modem.

The MAX232 is a dual driver/receiver that includes a capacitive voltage generator to supply EIA-232 voltage levels from a single 5-V supply. Each receiver converts EIA- 232 inputs to 5-V TTL/CMOS levels. Each driver converts TTL/CMOS input levels into EIA-232 levels.