I am modifing a keyless deadbolt (smartcode) to add an rfid reader(ID-20).I want to keep the manual code entry capability of the deadbolt and just add the option of using an rfid card. I have the rfid already configured with the arduino and the program written to scan a card and determine if it is an authorized card or not. I now need it to be able to unlock the deadbolt with the arduino.
I know that I could just wire the motor in the deadbolt to an H-bridge and have the arduino open it that way, but I would rather not. I want to use the arduino to enter the code electronically by tapping into the keypad buttons. My question is: what would be the best way of doing that? Below is a pic of the deadbolts keypad. Please refer to it to get a better idea of what I'm talking about. Thanks!
The colored lines were for my reference; but basically there are 6 buttons that connect to the numbered pads at the top left hand side of the circuit board. The pads are connected to wires, on the opposite side, that run back to the keypad micro controller. Each numbered pad serves as a neg or pos to two different buttons.