02-10-2012, 06:28 PM
sir can you give me the explaination of the entire working of this project with schematics
02-10-2012, 06:28 PM
sir can you give me the explaination of the entire working of this project with schematics
03-10-2012, 11:38 AM
to get information about the topic "sms based wireless electronic notice board using cdma" full report refer the link bellow
https://seminarproject.net/Thread-sms-ba...bile-phone
02-11-2012, 05:36 PM
SMS Based Wireless Electronic Notice Board using GSM/CDMA/3G Mobile Phone
SMS Based Wireless Electronic.docx (Size: 1.25 MB / Downloads: 42) ABSTRACT Notice Board is primary thing in any institution / organization or public utility places like bus stations, railway stations and parks. But sticking various notices day-to-day is a difficult process. A separate person is required to take care of this notices display. This project deals about an advanced hi-tech wireless notice board. The project is built around the ATMEGA8L micro controller from Atmel. This micro controller provides all the functionality of the display and wireless control. It also takes care of creating different display effects for given text. Display is obtained on LED Matrix Display Array on a printed circuit board. A GSM/CDMA Mobile Can is used to enter the required text or notice. The scrolling speed of the text also can be changed according to user requirement. After entering the text the SMS is sent to the no which is connected to the LED display. At any time the user can add or remove or alter the text according to his requirement. At the receiving end the GSM modem which is connected to the Max 232 receives the message and is connected to the microcontroller ATMEGA8L. The message which is already stored in the EEPROM is displayed on the LED Matrix Display Array. This project uses regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac output of secondary of 230/12V step down transformer. INTRODUCTION Notice Board is primary thing in any institution / organization or public utility places like bus stations, railway stations and parks. But sticking various notices day-to-day is a difficult process. A separate person is required to take care of this notices display. This project deals about an advanced hi-tech wireless notice board. An embedded system is a combination of software and hardware to perform a dedicated task. Some of the main devices used in embedded products are Microprocessors and Microcontrollers, Microprocessors are commonly referred to as general purpose processors as they simply accept the inputs, process it and give the output. In contrast, a microcontroller not only accepts the data as inputs but also manipulates it, interfaces the data with various devices, controls the data and thus finally gives the result. As everyone in this competitive world prefers to make the things easy and simple to handle, this project sets an example to some extent. This project is built around the ATMEGA8L micro controller from Atmel. Micro controller provides all the functionality of the display and wireless control. It also takes care of creating different display effects for given text. Display is obtained on LED Matrix Display Array on a printed circuit board. A GSM/CDMA Mobile Can is used to enter the required text or notice. The scrolling speed of the text also can be changed according to user requirement. After entering the text the SMS is sent to the no which is connected to the LED display. At any time the user can add or remove or alter the text according to his requirement. At the receiving end the GSM modem which is connected to the Max 232 receives the message and is connected to the microcontroller ATMEGA8L. The message which is already stored in the EEPROM is displayed on the LED Matrix Display Array. EEPROM (ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY) EEPROM one can select which byte to be erased, in contrast to flash, in which the entire contents of ROM are erased. The main advantage of EEPROM is that one can program and erase its contents while it is in system board. It does not require physical removal of the memory chip from its socket. The EEPROM used in this project is 24C04 type. The ATmega8L implements 2K bytes of on-chip EEPROM for data storage and 256 bytes of RAM. The upper 128 bytes of RAM occupy a parallel space to the Special Function Registers i.e., the upper 128 bytes have the same addresses as the SFR space but are physically separate from SFR space. DESCRIPTION: The 24C04 is a 4Kbit electrically erasable programmable memory (EEPROM), organized as 2 blocks of 256 x8 bits. They are manufactured in ST Microelectronics’ Hi-Endurance Advanced CMOS technology which guarantees an endurance of one million erase/write cycles with data retention of 40 years. Both Plastic Dual-in-Line and Plastic Small Outline packages are available. The memories are compatible with the I2C standard, two wire serial interfaces which uses a bi-directional data bus and serial clock. The memories carry a built-in 4 bit, unique device identification code (1010) corresponding to the I2C bus definition. This is used together with 2 chip enable inputs (E2, E1) so that up to 4 x 4K devices may be attached to the I2C bus and selected individually. The memories behave as a slave device in the I2C protocol with all memory operations synchronized by the serial clock. Read and write operations are initiated by a START condition generated by the bus master. The START condition is followed by a stream of 7 bits (identification code 1010), plus one read/write bit and terminated by an acknowledge bit. POWER ON RESET VCC LOCKS OUT WRITE PROTECT: In order to prevent data corruption and inadvertent write operations during power up, a Power on Reset (POR) circuit is implemented. Until the VCC voltage has reached the POR threshold value, the internal reset is active, all operations are disabled and the device will not respond to any command. In the same way, when VCC drops down from the operating voltage to below the POR threshold value, all operations are disabled and the device will not respond to any command. A stable VCC must be applied before applying any logic signal. SIGNAL DESCRIPTIONS SERIAL CLOCK (SCL): The SCL input pin is used to synchronize all data in and out of the memory. A resistor can be connected from the SCL line to VCC to act as a pull up. SERIAL DATA (SDA): The SDA pin is bi-directional and is used to transfer data in or out of the memory. It is an open drain output that may be wire-Oared with other open drain or open collector signals on the bus. A resistor must be connected from the SDA bus line to VCC to act as pull up. CHIP ENABLE (E1 - E2): These chip enable inputs are used to set the 2 least significant bits (b2, b3) of the 7 bit device select code. These inputs may be driven dynamically or tied to VCC or VSS to establish the device select code. |
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