Kamal parmar, M-tech in embedded system, Ganpat university,Ahmedabad. email@example.com
Abstract— LED's are a fantastic way to illuminate any kind of sign, be it lettering or panels.LED Dot-Matrix Displays are a common sight now a day on streets, malls, Buildings, parks and other public places. It is a way of visual information where large LCD and other display become too much expensive. My project is based on the wireless LED board . GSM and GPRS based Designs are Public utility products for mass communication. This is a Scrolling (Moving) Message Electronic Display Board which displays the messages received as SMS.This project provides an efficient for a when we change any notice which it’s displaying on board. It’s very easy and we can change our notice from anywhere. A LED Display Board Indoor Advertising Display can be used by companies to advertise even in bright day-light conditions. The display board displays any character send from the mobile which is interfaced using GSM to a microcontroller that initializes the led driver. The advantage of this project is that size of the display board can be increased row wise and column wise without making any changes in the circuitry since display board is the repetition of a small independent module.
Keywords— LED MATRIX,GSM MODEM,WIRELESS DISPLAY BOARD.
This project is aimed at developing a system that will display the message received by the cell or a modem. Microcontroller then will control the system by doing authentication and AT commands. And the messages that is been displayed LED display with interfacing it with AT89c51. This system is easy, robust to use in normal life by any-one at any place. This paper consists of basic introduction, block diagram, software used and many more details on this project. We propose a mobile-based notice board system that consists of a GSM SIM 300, and a microcontroller. The notice is been displayed by the microcontroller, which operates according to the user commands received from the mobile phone via GSM. In our project system is built upon an SMS (short message service) mobile cell module and a microcontroller, allowing a user to display real-time messages. This report presents the design and implementation of SIM 300 AT modem using AT commands and RS 232 Serial Comm. port. Microcontroller used in our project uses AT commands to monitor SIM 300. It receives incoming message, manipulate it and take appropriate actions. It also informs the user via creating the SMS that contains information about actions which is to be performed and sending it to the SIM 300 mobile via the serial port.
For the first step, we designed one circuit to connect mobile to PC and we created a communication link via HYPERTERMINAL. .
Mobile to PC interface
A. GSM Modem
For this type of application we needed the GSM cell phone which supports AT commands. After many searches we found out that Motorola C168 is the only mobile which supports each and every AT command. For serial communication we have used 2.5mm jack cable with the jack provided in mobile. B. AT89c51(Microcontroller)
We decided to go with AT89c51 rather than with other microcontroller because of many advantages as per our requirement like low in cost, more easier in program and also it have sleeping mode for better power consumption.
A. AT Command
* AT commands are instructions used to control a modem. AT is the abbreviation of ATtention. Every command line starts with "AT" or "at". That's why modem commands are called AT commands. Many of the commands that are used to control wired dial-up modems, such as ATD (Dial), ATA (Answer), ATH (Hook control) and ATO (Return to online data state), are also supported by GSM/GPRS modems and *
AT +CMGS| Send message|
AT +CMSS| Send message fromstorage|