Hack a cheap remote light switch with an Arduino Leonardo
Chris Lovett used a cheap wireless remote to control his Christmas lights; however, when the fob’s A53G 12V battery died, he decided to go a different direction. Rather that just replace the battery, he hooked up an Arduino Leonardo for full lighting automation.
For this hack, he bypassed the onboard IC and instead sent a simulated signal produced by the Leonardo through the wireless transmitter. The appropriate signals were decoded by a logic analyzer, then sent using one output pin to power the transmitter and a second to output the correct pulses. Full automation was accomplished via a Python Script running on a computer to activate the Leonardo at sunset and sunrise.
Arduino code can be found here, along with the Python script, if you’d like to try something similar.