newbie question

[JD123]

I can't make out that part as the pictures don't show those connections in full. Anyway, use pull-up resistors on the data pins going to the LCD or the weak pull-up port option if it's available on those pins. Past that, it maybe a code issue.

Post a clear picture of the pins to LCD connections and post some code.

[daphne8888]

Thanks JD123.i have my work done half way!but now i have another problem.I'm trying to write a simple password system which can confirm the password that i keyin at the beginning.Do u have any idea?i try to search through internet but cant find the one i really understand with.
i also attach my circuit diagram and some coding.Please tell me if i make any mistake.Thanks again.

[JD123]

For a password, I'd use logic like this:

(Every key pressed sends "#" so that someone looking over your shoulder can't see what you entered.)

password is a an array that you setup and holds the password value

for i = 0 to 3 'for 4 digit password
read keys
if no key, re-read keys
if key pressed <> password[i] then fail = 1
send LCD "#", no CR of LF
next i

if fail = 0 then go forward, else LCD "FAIL" (or something), clear LCD, fail = 0 and go back to password loop


This only the logic flow, not verbatim code.

[daphne8888]

thanks alot guys..i have made it!!!
i really appreaciate alot..