Keypad for PicLock project

[dorkygrin]

Newbie here just getting back into basic projects and hobbies. So, I was at Harbor Freight today and bought all kinds of cool things. New autoranging DVM, Soldering station, a driveway monitor for my "212" style camera project and some other goodies.

But one thing I got all excited about was a 'fake' keypad that I surmised was a real keypad that just activated a couple of LED's. Here's a distant picture of it:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96652

It was only $5.00 !!! So, I had to buy it cause I just KNEW it would be useful for a project that I've had floating in my head about activating my garage door opener. My thought was that I could use a picaxe to scan the keypad if the right digits were entered, activate a relay connected to my spst garage door switch and Bingo, I wouldn't have to worry about my daughter losing the house key again and again.

Then I saw this:

http://www.rev-ed.co.uk/docs/chi008.pdf

(It's a PicLock self assembly Kit)

This kit is MADE for my project. Sweet.

However, I've now got a keypad and I also happen to have a 14M.

Question is, could I just modify the code and use a 14M and skip a row? I guess I just answered my own question.

Anyway, a weatherproof keypad for $5 seemed like a great deal.

 

[212]

That make it much easier for these guys, when you answer your own question like that I saw that, but I didn't know it lit up and made noise too...cool!

 

[westaust55]

Keypad Lock projects

For another key lock project, you can also look at the Exemplar Projects which can be access from the PE.

With the Program Editor running and a program window open,
From the toolbar select Help / Picaxe Catalogue.

A small window will pop up. At the bottom right of that window is a button labelled "Exemplar Projects".

Click that button and you see a list of projects. Select the Keypadlock project and connect which will open the pdf file for that project. The pdf includes a program listing for a keypad such as you are using.

 

[BeanieBots]

Does your "fake" keypad actually have seperate keys?
It's cheap because it's FAKE. Probably only one button.
Too good to be true usually is.

 

[Michael 2727]

You can make a simple keypad out of a single button.

Use "COUNT" to detect how many button presses you need/want to make your
the code to jump to another location, then you can output a tone or note and
repeat the process a few times.

Eg: First press - one tone is heard (start tone) -
3 button presses (within a 3-Sec Timeout) -
Two tones are heard (verify tone) -
5 button presses (within a 4-Sec Timeout) -
Three tones are heard (verify tone) -
2 button presses (within a 3-Sec Timeout) -
etc, etc.
Unlocked.

Any incorrect number of button presses resets the code back to the start tone.

It's not the most uncrackable solution but it works.
You could even include a B? +1 counter that after so many (X) failed attempts
would lockout the button for a few minutes.


2¢ worth.

 

[BeanieBots]

Michael, you say "not the most uncrackable solution " but I think it is probably more secure than the 'conventional' method.
You could even write the code next to the keypad. People wouldn't know how to enter it Just avoid having "4" as your first digit if it's a 4 digit number.

 

[Michael 2727]

I've used this method to select the "First Digit", "Second Digit" temperature set points
and 30 Sec Delay increments for Hysteresis (dead band) in my 08M/DS18B20 thermostat.

This method can be used in a variety of ways to input data if you only
have a single pin left on your next project

You could also use the "one wire keypad" version and an ADC input which
has been discussed previously on the forum. Try Search

 

[hippy]

"Keypad beeps when pressed"

First thing I'd do is rip it apart and see how the keys are wired up, whether there's a switch per button or something else. Once you know that you can then weigh up the options of what to do. That it beeps means something is wired up and just that gives a number of options as noted above.

 

[dorkygrin]

KeyPad Picture

OK, here's some pictures of that Keypad. It looks promising to me with lots of potential.

I'm open to suggestions regarding how to use it in a project. Seems like I need to identify the rows and columns and solder some wires to them?

Anybody know what that chip is on the board?

 

[dorkygrin]

Sorry

Geez, sorry those pictures are so big. That's the detail i needed though to look up that that chip is. I couldn't read it until I took that pic (time for reading glasses!)

Quote:

"EM78P153S is an 8-bit microprocessor with low-power and high-speed CMOS technology."

Too bad I can't just mount a picaxe in place of that!

 

[Rickharris]

A simple 4 push button code with push buttons to pin 1 - pin 2 - pin 3 - pin 4 output to lock pin 0 could be

open code is 1324 - assume high 0 opens lock - low 0 locks it.

start:
if pin 1=1 then number2
goto start 'sends code back to start if incorrect number pressed.
 
number2:
if pin 3=1 then number3
goto start
 
number3:
if pin 2=1 then number4
goto start
 
number4:
if pin4=1 then open
goto start
 
 
open:
 
high 0
wait 10
low 0
 
goto start

 

[hippy]

The PCB's look promising. Hard to tell exactly how the switches are wired but it looks like it's a fully working keypad but programmed as a fake one. Even if it isn't, it looks like you'd be able to cut various tracks, remove the micro, and turn it into a N x M matrix or something else.

 

[dorkygrin]

14M

Thanks for the tip Westaust. I'm trying to figure out if my 14M will work in place of the 28. I can eliminate the LED outputs (pin 25/26) and still be OK as far as inputs and outputs go.

But I'm not sure what the 4 MHz resonator is for. Any hints?

Also, would I run into a lack of memory issue by using the 14M?

For another key lock project, you can also look at the Exemplar Projects which can be access from the PE.

With the Program Editor running and a program window open,
From the toolbar select Help / Picaxe Catalogue.

A small window will pop up. At the bottom right of that window is a button labelled "Exemplar Projects".

Click that button and you see a list of projects. Select the Keypadlock project and connect which will open the pdf file for that project. The pdf includes a program listing for a keypad such as you are using.

 

[papaof2]

Some of the bigger chips required an external resonator as they did not have an internal clock. Not a concern with the 14M as it has an internal clock.

John