The “wire.h” library allows you to communicate with I2C / TWI devices(RTC Module).The address of the I2C device is mentioned on the beginning of the program.The name and ID code of every staff should be enrolled in this array on the programming time.
Reading the time from your RTC IC is just as simple, in fac, the process can be followed neatly inside the function display Time().
Two pointer arrays are declared at the beginning which contains the RFID codes and names of the persons.
Our system uses a 20 x 4 LCD module for displaying purpose.
The working and interfacing of 20×4 LCD module is similar to that of 16 x2 LCD expect that it consist of few more rows and columns. The RTC Module is connected to the Arduino using I2C protocol.
These are necessary because the RTC ICs work in BCD not decimal. Using it is very simple to insert the values from year down to second, and the RTC will start from that time.
Once you have run the function once it’s wise to prefix it with // and upload your code again, so it will not reset the time once the power has been cycled or microcontroller reset.
The same RFID attendance system can also be developed using popular development boards like Arduino, Raspberry Pi etc.
The choice of a microcontroller or a development board is purely based on the additional features and functionality you plan to incorporate into the system.
The Arduino pins to which the buttons are connected are configured as “INPUT_PULLUP” within in the program.
This will eliminate the use of of external pull up resistors by enabling the internal pull ups of Arduino.