Remote Controlled Door-lock

Transistor-relay assembly and a solenoid

The Java ME and Android SDK learning curve is exponential and taking ages. So for fun, I'm taking time out to adapt one of my earlier projects "The remote firework firing device" . It's actually a small step to adapt the code and have the Keypad RC trigger the relay to push-and-pull a solenoid. The solenoid is the deadbolt for a door lock.

It's one of the things I love about Arduino - you can make a prototype then change the software and it becomes something else so easily!

No hardware adaption is needed on the control side, but I want to replace the eight relay board, on the receiver-side, with a single transistor-relay assembly and a solenoid. When the correct PIN number is entered on the keypad a signal is sent over RF and the receiving Arduino activates the circuit, unlocking or locking the door. See the circuit above.