Over time we've collected a fair few sets of Christmas lights, the LED ones with a 'wall wart' power supply and selectable options. However this year we've noticed that when we unplug them, they drop back to the initial flash setting. I've found a youtube video from Big Clive that explains why, it's purely a cost cutting measure (one less chip on the board apparently). The problem when we use something like a Tapo plug to control the lights, we're stuck with basically the demonstration flashing pattern. We like flashy, just not that flashy!
I want to replace the circuit with something a bit more controllable, my initial thoughts were something Pi powered. I've figured out that the LED's cycle through their colours by using alternating current. I've also found 'LED controllers' but they're more for proper displays and wouldn't deal with something as common as alternating LED's. I think just a decent power 1hz sine wave output would do, as long as I could meet the voltage and current requirements. Does anyone have examples of circuits or drivers that could handle this type of LED configuration?