Ever need to hack your intercom system? I asked my friends on NYC Resistor and they helped me figure out how_
- Get an RF remote transmitter and receiver and power adapter - they're pretty cheap from electronickits.com
- strip the power adapter wires
- wire the power adapter wires into the RF receiver (check voltage to know which is negative and positive)
- test the power by pressing the "learn" button on the receiver
- "learn" your receiver - press the "learn" button on the receiver and start transmitting with your key transmitter
- open up your intercom system and find the wires that hook in the "unlock door"
- using the voltometer, test your intercom to see if your circuit is closed and needs to be opened (via the relay) or opened and needs to be closed (again via relay)
- wire from the RF reciever to the intercom, then from the intercom back to the receiver to complete the circuit - it'll either be Normally Closed or Normally Open
- test the transmitter triggers the relay (button one does Normally Open, button two does Normally Closed for me) and it should trigger the intercom "unlock door"
Here's another solid example of keyless entry from Make
Below is a quick gallery of images of the process! Hope this helps!