Vermes
Advanced Member level 4
This is a project of digital trigger. Atmega8 is connected with transistors. The board requires 0b101 to activate the relay, so the system can not be switches accidentally. It is much less possible that there would be 0b101 on a port than for example 0xFF or 0. Supply is via 7805 (there are also pins for direct connection 5V). Between the relay and output there is also a switch, so the output can be disconnected in any moment. The board is also equipped with three micro switches Programming pins used were removed from an IR receiver.
Control is carried out using three buttons. Two of them are used for setting the time +/- and the third one for starting the countdown (you should hold it down for a moment). Remote control can be done the same way. The range of time is 10 to 99 seconds with 5seconds step.
A wire soldered to the board between the relay and contact is added in case of greater currents.
Pictures:
Link to original thread - Wyzwalacz cyfrowy [atmega8][IR][C]
