Link is given below to download the project file and program source and hex files.
This is a relay on/off system what you can also use as a programmed keypad based code lock system. I used microchip PIC micro-controller which is a 40 pins DIP and 8-bit micro-controller.
Once it is powered on The LED in the circuit will light up. This makes you sure that power is connected. This LED can also be used for another relay you just need to use another transistor as a switch in order to turn the relay on/off. So once the board is powered up you'll see the display on the 16x2 character LCD (162JD). Now as i told in the video we enter the code by using the 4x3 matrix numeral keypad. Firstly it will say to press * and when you'll press it it will ask to enter the code. Now you enter the code what is pre-saved in the HEX file. Now if you don't want that code, simply enter the master code (which can also be changed in the source code file) of five (5) digits, it will then ask for the new code. You enter in it and hence the screen is back at press *. Now your new code is saved.
You press *, then enter your newly saved four (4) digits code and press # the output pin will be turned high of the micro-controller where you connect the relay and that power LED will be turned off.
Now simply press the zero button and release it it will turn off the connected relay.
If the code is entered wrong again and again there will be dialog "Access Denied" will appear. In order to clear it you need to reset the PIC16F877 as i have the red button on it.
I have included the Proteus project file, full schematic, source code & HEX file in the archive what you can directly download by the link given below:
***LINK*** (The first link is currently not working) We'll update it soon.http://samtechpro.blogspot....
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