Safrianti, Ery2014-03-042014-03-042014-03-04wahyu sari yenihttp://repository.unri.ac.id/xmlui/handle/123456789/5760Sending messages using mobile technology nowadays is a need to communicate, other than that this technology can also be applied to other sectors such as security. This research aims to make a car safety control devices using a wireless network by sending an SMS (Short Messages Service). Control is done by using a microcontroller linked to mobile phones via SMS. Users send a text message from the HandPhone system (mobile) previously process by ATmega8535 AVR microcontroller. The cellphone will send AT Command, then the message is received by user Hp (placed in the car). Siemens format used for receiving and sending data is known as Module PDU (Protocol Data Unit) and the module called the AT Command. The design consists of designing electronic circuits, control alarms, data cable, and microcontroller. Serial communication used in communication between mobile phones and microcontrollers. Design software using assembly languageenMicrocontrollerSMSPDUAT commandsLimitSwitchUR-Scientific Work Lecturer