GSM Based Stepper Motor Monitoring and Speed Control

In this paper, the design aspects of an embedded device which can control stepper motor by sending a specific SMS message from a mobile phone are presented. This controller is extremely handy at places where we have to control the ON and OFF switching of the devices but no wired connection to that place is available. GSM (SMS) controlled stepper motor is automatic control system which is capable of receiving a set of command instructions in the form of Short Message Service and perform the necessary actions like start, stop and speed control. We use a dedicated modem at the receiver module and send the AT commands using SMS service as per the required actions. The mobile unit is interfaced with microcontroller so that it takes the responsibility of reading the received commands in the form of SMS and performs the predefined tasks such as motor start, stop, motor direction and speed control.