A Pair of Radio Frequency Transmitter and Receiver
I made a radio frequency transmitter and receiver. In the movie, I put the receiver in the house, started the movie recording and took the transmitter outside.
At 0:21 to 0:23 you could hear the sound of the door open and closed, when I left the house.
At a distance around 60 feet (20 meters) from the receiver, I used the transmitter to send a signal to the receiver, which received it and the red LED lit up (see video at 0:53).
At 1:18-1:21, you could hear the sound of the door open and closed, when I came back to the house.
I took the transmitter to around 150 feet (50 meters) away once more and sent a signal, the receiver received.
This transmitter and receiver pair could be used as a remote shutter release switch in DSLR cameras as long as the camera has a port for shutter release.
https://www.youtube.com/watch?v=qrEvQQRMW9s
What does the pair look like？ see: https://www.youtube.com/watch?v=aMS_zih7uNs
