Need Help in Digital Lock Using AT89C2051 with LCD and Keypad - Assembly

hello...i need help regarding the above project...

i have downloaded this project from the link below :

http://www.8051projects.net/download-d206-digital-lock-using-at89c2051-lcd-keypad-assembly.html

the problem is, the LCD only shows black box...i have connected the circuit just like the given circuit diagram...from the circuit, it didn't show on how to connect the pin 7, 8, 9, and 10 of the LCD..so i follow from the tutorial and connect the pin to the ground..and for pin 15 LCD, i connected to VCC and pin 16 to the ground..

by the way, i'm using 5V voltage regulator because my source is 9V battery...

may i know what is the cause of my problem where the LCD only shows black box..?

Did you connect pin 3 (contrast) to a pot, and have you tried adjusting it ?

yup...everything is connected as in the diagram and the pot is working perfectly...

just now i check the voltage after the regulator, it show above 7V...after changing the regulator circuit and acquired 5V, i try with the digital lock and thank God...it working and the LCD show the output...hehe...

btw, thanks for the reply...i really appreciate that...

btw, thanks for the reply...i really appreciate that...

izam88

Thanks
Glad it's working now

Lucky you your controller and LCD is safe

sir...can i use at89c51 instead of at89c2051 in "Digital Lock Using AT89C2051 with LCD and Keypad - Assembly " if yes then how??? and how can i program at89c2051??
please help me asap...thank you...

@rupraj, you can use 89C51 instead of 2051. Just use same port pins. no need to change any code.