DESIGN INTRODUCTION
DESIGN INTRODUCTION
In our daily life, the security of house, company department, documents and finance forms,
also some personal information always used the lock to protect them. If use the normal keys
to lock out the door, we should taken many keys with ourself.That is so difficult to use. And if
we lost the keys with careless, the security looks very easy to break out. As the developing of
the technology,people
ask for high securty machines.For satisfy this request, the cipher lock is appeared.The cipher
has higher security, lower cost, lower power and easy to use.
Base on the thinking of the cipher lock, this design uses AT89C51 of ATMEL COMPANY to
carry out the SCM digital cipher lock, its main function as follow:
1. set password with 6 words, enter the words via keybord, if enter the right number, the lock
will unlock.
2. password can set and fix by yourself, you can just fix the password when the lock is
keeping unlock. It need to enter the new password twice to avoid the wrong activity.
3. alarm function. If enter the wrong password, the mon will show the error message, when
enter the wrong password over 3 times, the buzzer will alarm and lock the keybord at the
same time.
this lock is made by 3 parts: gob circuit of 4x4 matrix keybord , gob circuit of cipher lock,
gob circuit of 8 way display output. other wise, the system has LED light, and warning
buzzer.
the main function of this cipher lock is carried out enter, clear, and change the password, and
unlock the door.
1. enter the password: press one number button, one signal "-" will show on the digital tube on
the right side, pls put the "-" to left side at the same time.
2. clear the password: press the clear button to clear all codes you have enter before.
3. change the password: use the new enter number as the new password.
4. unlock function: press the unlock button, the system will check up the enter number and
password, if yes the lock will open, if not it keep lock.
the main process: first, use SCM AT89C51 of ATMEL company. second, design the theory
chart with DXP 2004, and design the PCB board. third, compile the C lang. program,
resemble, and test with software keil uVision3. fourth, simulate the hardware test with
software PROTEUS. LAST, test the circuit board withe the software and hardware, finish.
Key word : matrix keybord; AT89C51: LED digital tube.
III
