RF Switching Module Can Learn New Remotes

February 20, 2013 by Mike Szczys 12 Comments

rf-remote-also-learns-by-itself

This breadboarded circuit is [Sergio’s] solution to controlling appliances wirelessly. Specifically he wanted a way to turn his pool pump on and off from inside the house. Since he had most of the parts on hand he decided to build a solution himself. What he ended up with is an RF base station that can learn to take commands from different remote devices.

The main components include the solid state relay at the bottom of the image. This lets the ATtiny13 switch mains voltage appliances. The microcontroller (on the copper clad square at the center of the breadboard) interfaces with the green radio frequency board to its left. On the right is a single leaf switch. This acts as the input. A quick click will toggle the relay, but a three-second press puts the device in learning mode. [Sergio] can then press a button on an RF remote and the device will store the received code in EEPROM. As you can see in the clip after the break, he even included a way to forget a remote code.

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Data Confirmation With RF Communications

October 18, 2010 by Mike Szczys 35 Comments

[Rafael] built a system that uses radio frequency for communications. The code he was using with the inexpensive receiver/transmitter pairs already had some error correction but from time to time an entire message would be missed by the receiver. He set out to make these RF communications more robust.

A little more than a year ago we looked at using these same transmitters with an Arduino. [Rafael] has a similar setup but since they are unidirectional he chose to use two pairs for bidirectional communication (each operating at a different frequency to avoid interference). On one end, a computer transmits data to the Arduino which is in a remote location. His confirmation protocol relies on a randomly generated message identifier. The computer will continually transmit the same message. The Arduino continually receives these messages, comparing them with the last successfully received message. If they match, it is considered a successful data transfer and the Arduino transmits a confirmation back to the computer which then starts transmitting the next message.

This isn’t an application-specific protocol. For demonstration purposes [Rafael] built a quick home automation setup that uses it to operate a house lamp.