Hi everyone, i'm currently processing a project about simulating a digital lock. In my project, i use 2 IC for basic functions like checking password, alerting, controlling relay. I do think that my project have some major problems so i go here to get instructions.
First, my project can not check the order of the right password. For example, if i set the password '1234', and i enter '1256' or '4321' the buzzer will not work. It only works if i enter 4 of those numbers 5 6 7 8 9 0.
Sencond, i do think i that my project needs improvement because uing 2 IC 4017 is a little bit simple.
This is my very first time of designing circuit and digital system so please give me instrustions and comments for improvement.

Thanks for your helpful advice

 

Welcome to AAC!

i'm currently processing a project about simulating a digital lock

Is this project for school? If it's schoolwork, post the complete text for the problem.

This is my very first time of designing circuit and digital system so please give me instrustions and comments for improvement.

Turn off that awful grid. You aren't using it anyway. Remove unnecessary wire jogs/whitespace.

 

Welcome to AAC!
Is this project for school? If it's schoolwork, post the complete text for the problem.
Turn off that awful grid. You aren't using it anyway. Remove unnecessary wire jogs/whitespace.

This is my school project. Lecturer only requires simulation on Proteus.

 

This is my school project. Lecturer only requires simulation on Proteus.

Post the complete text for the problem.

I'll flag your post to have it moved to the Homework Help forum. You'll be expected to do most of the work there as members can only offer guidance.

 

Post the complete text for the problem.

I'll flag your post to have it moved to the Homework Help forum. You'll be expected to do most of the work there as members can only offer guidance.

I am designing a simple electronic combination lock as a student project.
The design must not use a microcontroller and should rely only on basic logic ICs.

 

This is my school project. Lecturer only requires simulation on Proteus.

Are you required to use only the 4017s?

 

Are you required to use only the 4017s?

No, there is no limitations in hardwares selection as long as they are digital one. The only constraint is that i can not use microcontroller. I do try using only logic gates then improving by using DFF but finally i chose to use 4017 because of its ultility.

 

The design must not use a microcontroller and should rely only on basic logic ICs.

Are there any restrictions on logic chips?

i chose to use 4017 because of its ultility

But it won't work for your case.

 

Are there any restrictions on logic chips?
But it won't work for your case.

No, as long as they are digial hardware. I intended to use basic logic gates and flipflops to implement my schematic but i failed

 

Hi Danyang,
I have moved your thread to the Homework forum.
Use the methods and diagrams that the Teacher has stated must be used.

Moderator.

 

For example, if i set the password '1234', and i enter '1256' or '4321' the buzzer will not work. It only works if i enter 4 of those numbers 5 6 7 8 9 0.

I see the problem with that in the circuit.

 

I see the problem with that in the circuit.

Maybe the 4017 can only check sequentially right?

 

Maybe the 4017 can only check sequentially right?

Correct, the unlock code 6-8-9-0 from the schematic looks OK.

 

There is a way using U9 4017 to activate the buzzer if the code is incorrect.
U9 needs to get pulsed regardless of which button is pressed.
Figure out how that would be accomplished.
If the correct code is entered, what is the output on U7 and U9?
What is the output on U7 and U9 if the code is incorrect?

 

There is a way using U9 4017 to activate the buzzer if the code is incorrect.
U9 needs to get pulsed regardless of which button is pressed.
Figure out how that would be accomplished.
If the correct code is entered, what is the output on U7 and U9?
What is the output on U7 and U9 if the code is incorrect?

Thank you. I will try but it seems kinda abstract to me

 

Think about this, if U9 is wired to receive a pulse regardless of which button is pressed after 4 presses the output on U9 would be what?