In Figure 3.1 is shown a diagram of the overall system box. HP Siemens M35 is used as an SMS Gatewa

The authenticity michael battaglia of this thesis research titled Design of Electric Lighting Equipment Control Using Cell Phone Remote, michael battaglia which controls electric lights using the facilities SMS (Short Message Service) to a mobile phone. This tool is also expected to monitor the state of electric lighting equipment whether alive or dead. Brand mobile phone is used is a type of Siemens M35. The system used is a serial communication system between Siemens M35 mobile phone with a microcontroller AT89S51. Microcontroller as control and monitor the state of electric lighting michael battaglia equipment.
In Figure 3.1 is shown a diagram of the overall system box. HP Siemens M35 is used as an SMS Gateway. HP with a microcontroller connected using the data cable that utilizes RS232 serial communication. This type of communication is used is UART models. The microcontroller has a role as a base system. Microcontroller will read and communicate with HP, then control the lights with the help of relay drivers, and read sensors that have passed a comparator. Driver mounted aims to control michael battaglia the lights work on AC/220V voltage. It is absolutely necessary because the microcontroller only works on TTL and CMOS voltage levels, so it is not able to directly control the lights. The sensor is a phototransistor is used to change the conditions of light into electrical quantities. In order for the analog sensor is able to be read by the microcontroller that is digital so it needs to be mounted a comparator. This comparator to compare the condition of the sensor duty that goes to pin (+) op-amp with a reference voltage at pin (-) op-amp when it's dark or light and converts it into a digital logic on its output pin. While not 74LS14 gate which has the ability to trigger pulse input and the output of the IC data sheet is already standard TTL that can be directly connected to the microcontroller. 74LS14 not gate is also used to reverse the situation so that the input voltage when the input high then it would be worth the low output.
Microcontroller Microcontroller is the main component that controls the entire system. The microcontroller used in this study is the Atmel microcontroller AT89S51 series. This series is a new variant of the family of the mengelami AT89C51 program changes the charging procedure. In this series has facilities ISP (In System Programming) which are not owned in the previous series. This facility allows the conversion of the content of the program even though the system is running. To work with this microcontroller needed some additional components that are often referred to as the minimum system. The terms of among others, the system clock or oscillator, reset the system and the ISP system. In this study, the minimum system michael battaglia presented in Figure 3.2.
Presented in Figure 3.2 AT89S51/52 microcontroller circuit schematic minimum. Support system that is the first oscillator system consisting of x-tal worth of 11.0592 MHz and two 33pF capacitors worth. Value of 11.0592 MHz chosen to generate the baud rate value is not an error. michael battaglia
Communication microcontroller and HP to communicate between the microcontroller and the necessary facilities HP model UART serial communication michael battaglia with 19200bps speed for the type of HP Siemens M35. This speed will vary depending michael battaglia on the type of HP are used. Voltage level used is RS232. While it only provides microcontroller UART serial communication with the TX pin, and Rx with RS232 voltage levels. It required an adapter system that can change the TTL voltage levels to RS232 levels. At HP Siemens M35 connectors are for communicating with external devices. This connector is usually able to be accessed by serial data cable. Generally the data cable is equipped with a RS232 converter to the microcontroller requires additional devices are modules of TTL to RS232 converter. Scheme presented in Figure 3.3 RS232 serial communication circuit.
To meet the required standard RS232 communication converter IC MAX232. This IC is manufactured michael battaglia by Maxim Dallas Semiconductor. In this IC is equipped with RS232 adapter michael battaglia system so stay T1IN connecting pins with pin TXD on P3.1 of microcontroller, and connect with R1IN pin RXD pin P3.0 of the microcontroller. In the HP before michael battaglia entering the terminal must first be converted to a voltage level that can be accessed by mobile phones. Generally michael battaglia this conversion michael battaglia is automatically performed by the data cable from the mobile phones. Model data cable connection to HP Siemens M35 depicted in Figure 3.4.
The model presented in Figure 3.4 compatible michael battaglia data cable connection to a PC. Presented in Figure 3.5 on HP Siemens M35 connections. In this there is a 2 pin connector as communication michael battaglia paths. In connection Siemen Mobile Phone