• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Help with designing an Electronic Lock

Status
Not open for further replies.

jossut

New Member
I'm working on the design of an Electronic lock as part of my EE senior project (I have two months to complete it), it has to have the following characteristics:

1)Use of a microcontroller.
2)different passwords for different users
3)user's log
4)interface to download the user's log
5)use of sensor to check if door is open or closed
6)use of a siren in case they try remove the lock or if open without entering a password
7)use of a video camera to record who is trying to unlock the door

I need some help about deciding which microcontroller to use, I have been thinking about the Basic Stamp 2 module but not sure, I got confused with the specification of this one about the RAM Size: 32 Bytes (6 I/O, 26 Variable). what does the 6I/O, 26 variables means with respect to the RAM size. Also, please tell me where I can look for microcontroller and other electronic components.

So, if anyone could help me with any ideas about what microcontroller to use and/or give me an explanation about the RAM size I really would appreciate it.

As the project will go, I'm sure I'll come back looking for more help
thank you

Guss
 

Nigel Goodwin

Super Moderator
Most Helpful Member
jossut said:
I'm working on the design of an Electronic lock as part of my EE senior project (I have two months to complete it), it has to have the following characteristics:

1)Use of a microcontroller.
2)different passwords for different users
3)user's log
4)interface to download the user's log
5)use of sensor to check if door is open or closed
6)use of a siren in case they try remove the lock or if open without entering a password
7)use of a video camera to record who is trying to unlock the door

I need some help about deciding which microcontroller to use, I have been thinking about the Basic Stamp 2 module but not sure, I got confused with the specification of this one about the RAM Size: 32 Bytes (6 I/O, 26 Variable). what does the 6I/O, 26 variables means with respect to the RAM size. Also, please tell me where I can look for microcontroller and other electronic components.

So, if anyone could help me with any ideas about what microcontroller to use and/or give me an explanation about the RAM size I really would appreciate it.
I would suggest something like the PIC 16F876, which will provide sufficient I/O pins for your project.

If you check my PIC keypad tutorials, one of them does much of what you're looking for, and could easily be expanded to do it all! - replacing the 16F628 with the 16F876 would provide enough pins.
 

leogc

New Member
pic for sure

I would also recommend using a pic uC. The 16f628 is a good one to learn on. You dont need a crystal and its fairly easy to use. If you can get a cross compiler and write your code in basic or C it will save you heaps of time.
 

dipal_z

New Member
Also try to choose the controller with internal EEPROM, you can use it store passwords and other settings.
 

jossut

New Member
thank you everyone for the help, I already kind of figured out almost everything, right now my only concern is about the video, is there a way I can get an X10 camera to just store images on eeprom?
hope, anyone can help me

thank you
 

Nigel Goodwin

Super Moderator
Most Helpful Member
jossut said:
thank you everyone for the help, I already kind of figured out almost everything, right now my only concern is about the video, is there a way I can get an X10 camera to just store images on eeprom?
hope, anyone can help me
You don't have your location filled in, so we've no idea where you might be?.

So assuming you're in Europe?, a video camera (which is all the X10 camera is!) outputs 25 full pictures per second, consisting of 625 lines (some of which are not actually visible lines). The full resolution is 768 pixels per line by 576 lines for full resolution, so assuming 8 bit sampling, and only monochrome, that's 442,368 bytes to store every 40mS.

EEPROM's are slow devices (particularly when writing to them), and also don't come that large - plus you also have the problem of digitising the video stream. If you want to do colour?, then your problems are multiplied further - by three times if you want to store RGB?.

I don't imagine for a second that your project requires you to try and build a digital video recording device? - your project is nice and simple, doing this would make it EXTREMELY complicated, and NOT a project for 2 months :lol:

If you want to record the video stream then use a VCR, they cost hardly anything these days, and you can easily modify it to be controlled by the PIC to start recording as and when required.

A better solution would be a hard disk recorder, as used professionally for security recordings, but these aren't cheap!.
 

jossut

New Member
Thank you for the advise Nigel, I already figured that out, so all I will do is construct some kind of switch to turn on the camera when people start pressing the keypad.
But now, I have another question. I need to create the interface by someway to download the user log to the pc, is it possible to read from memory and send it to the pc? i only need to write some program? can i use the serial port of the micro? I'll be using the basic stamp 2

Thank you, hope u can help me
 

tansis

New Member
Coughs quietly ...

Is the device to Fail Safe , or Fail Secure when in use ?
 

Nigel Goodwin

Super Moderator
Most Helpful Member
jossut said:
Thank you for the advise Nigel, I already figured that out, so all I will do is construct some kind of switch to turn on the camera when people start pressing the keypad.
But now, I have another question. I need to create the interface by someway to download the user log to the pc, is it possible to read from memory and send it to the pc? i only need to write some program? can i use the serial port of the micro? I'll be using the basic stamp 2
Yes, it's very simple to transfer data from the PIC to a PC via a serial interface.
 

electronist

New Member
If you are going to make use of a PC then why do you require a VCR. You could simply carry out the recording on your hardisk.
 

jossut

New Member
Ok, thank you nigel I'll read the manual to start figuring out how to do it. So far I started doing some circuits to play with the micro. I got it to read a switch and turn on a LED for a few seconds when the button is pressed.
thank you again everyone
 

Nigel Goodwin

Super Moderator
Most Helpful Member
jossut said:
Ok, thank you nigel I'll read the manual to start figuring out how to do it. So far I started doing some circuits to play with the micro. I got it to read a switch and turn on a LED for a few seconds when the button is pressed.
thank you again everyone
Check my tutorials, they do most of what you need!.
 

eblc1388

Active Member
jossut said:
I got confused with the specification of this one about the RAM Size: 32 Bytes (6 I/O, 26 Variable). what does the 6I/O, 26 variables means with respect to the RAM size.
It means the Stamp2 has 32 Bytes of RAM but six bytes of them is involved in I/O operation so you should NOT use them to store values that are not related to I/O. Doing so could possibly change the function or logic level of pin(s).

Therefore, 26 bytes of RAM is left over for other use.
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top