You can do lots of things with iButtons, from electronic door locks to security systems, this tutorial will show you how to make a simple but very useful iButton application for electronic locks.
- Door strike
- PIC Microcontroller
- 7 segment LED display
- Power transistor
- 5v regulator
- Momentary switch
- iButton reader
- iButtons type DS1990A
- 12v source
The PIC has the number of the iButton master programmed into the EEPROM.
When the master iButton is touched against the iButton reader the PIC goes into a routine waiting for a user iButton(s) to be touched against the reader.
When this iButtons is touched it is allocated a number 0 to 9 which appears on the 7 segment led display and the iButtons number is also written to the PIC’s EEPROM.
The user iButton when touched against the reader will now activate the door strike for 5 seconds.
The process can be repeated for another 9 user iButtons.
To deactivate a lost iButton, touch the master iButton against the reader, and push the switch a number of times until the number of the lost iButton appears on the 7 segment display, then touch the master iButton against the reader.
The hex file of the software and circuit diagram can be acquired by me, Ligeti: firstname.lastname@example.org, please write iButton in the subject of the Email.
We also have a limited number of the iButtons and readers for sale.
A more secure system can be constructed by using an iButtons with memory such as the DS1992L.
Please feel free to comment, and ask questions if you have any.