Hello sir, Iam new to microcontrollers, and now iam doing a project on access control, wherein the microcontroller(AT89C51) has to read the data from the card reader( the id), check from the data stored and display the persons name and designation. kindly help me, by giving me an example code. I have a separate code for serial interface and a code fo lcd interface, the serial interfae code works in turboc, and the lcd interface code works on keil, but when i try calling the lcd program as a function in the serial interface program and try running it in keil, there is a root segment error, or sometimes there is an c141 error. Please help me. thankyou, michelle.