With the growing importance of the embedded systems, the need to design embedded applications with microcontrollers having advance features is gaining prominence. In the presented work I2C protocol is
used to make an interactive information display that can be used at various places for providing information relevant to the customer, public or student. For example it can be used as an inquiry display in the university inquiry offices to help the students regarding the queries they have by displaying the proper information on the display module time to time. This embedded system is having serial link with the host computer for sending the data to the information display module. More intelligence are added in the presented work by password protecting the system access so only authorized person can send the message or information to the display. Once the information is send to the display module it is also stored in the external memory using I2C protocol. If the system is disconnected from the computer them the last stored message will be displayed on the display module.
Keywords: Embedded System, I2C protocol, External memory interface, Interactive Display modules,
MCS51 Family of Micro controllers (8-bit)
[...] Often, multiple slaves can use common data and clock lines, with each slave having its own select line or address. One of the most popular synchronous interfaces is the inter-integrated circuit which was developed by Philips nearly 20 years ago. I2C is a low-bandwidth, short-distance, two wire interfaces that was originally designed to enable communication between devices inside a TV. Now, I2C interface is implemented in over 1000 different devices. Some microcontrollers have a hardware I2C controller built-in (e.g., the P8xC528 from Philips and the PIC16C6x from Microchip). An all-software implementation of I2C protocol is also possible. [...]
[...] In our case the system is connected to port1 so COM1 is selected as shown above. Press OK and provide the configuration as shown in the Figure6. Figure-6: Baud Rate configuration. Press if you want to save the string and display it on the LCD display. After storing the information HyperTerminal will be disconnected from the system. For changing the string again please once again connect to the hyper terminal as explained above and proceed further or stay connected to change the string in short time durations. [...]
[...] The I2C family of devices interfaces directly with industry standard microcontrollers such as the Intel MCS-51 family. This family includes 8031/8051 and 8032/8052 (ROM less/ROM) family types. I2C E2PROMs are 2-wire interface, nonvolatile memories ranging from 2K bits (AT24C02) to 64K (AT24C64K) in density. They adhere to the I2C protocol which uses 2 lines, a data (SDA) and serial clock (SCL) line for all transmissions. The AT24C02 E2PROMs has an 8byte page write buffer and a write protect pin for inadvertent write protection. The AT24C02, AT24C08 and AT24C16 devices have 16 byte page write buffers. [...]
[...] In this presented work, such an implementation for the popular 8051 microcontroller is provided BLOCK DIAGRAM AND DESCRIPTION The block diagram of the Interactive Information display embedded system using i2c protocol is shown in Figure-1. Transmit 3.0 ) and Receive 3.1 ) pins are connected with the level translator IC MAX 232 and that is connected with the RS232 DB9 Female connector. A cable is made with DB9 Male and DB9 Female connector's at both ends respectively. This connector cable is used to connect the circuit board with the PC for receiving data INTERFACING AT24C64 WITH MICROCONTROLLER Figure-1: Block diagram of the Interactive Information Display embedded system using I2C protocol. [...]
[...] The first screen of the HyperTerminal is shown in the Figure- CONFIGURING Press Apply and Ok to start the HyperTerminal startup screen as shown in the Figure-7. Figure-7: HyperTerminal Startup Screen. As one get connected with the HyperTerminal the following string will be displayed on it as one resets the system. WELCOME . “Interactive Information Display embedded system using I2C protocol” Enter your username and Password for the changing the string to be displayed on 16x2 LCD display Press to quit from the program. USERNAME: (Note: Enter the valid username. [...]
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