Vermes
Advanced Member level 4
It is a simple system which opens the door so that you do not have to answer a call.
How it works:
After the ring button was pressed three times (short signals), Atmega provides voltage to the relay and shorts the contacts of electromagnet for 3 seconds. It does not react for any other code. The whole device is powered from intercom. The device is very cheap and its size is small so that it can be closed in housing of the intercom. Everything was mounted on an universal board.
To change the parameters of opening, you have to change some variables in the program:
- maximum time of short press
- maximum time of long press
- maximum time of gap
Pictures:
Link to original thread - Modyfikacja domofonu- otwieranie "kodem"