You can easily find a 5 m RGB LED strip and controller for under $15 on amazon. The controllers have an IR remote and receiver that lets you select (and in more recent versions, program) a number of different lighting options. They are fairly cool, but IR remotes require line of sight and just aren’t as cool as using your phone/tablet/computer.
The internals of this guy are fairly simple.
- An IR receiver (blue)
- An EEPROM that converts the IR signal and sends it over serial (green)
- An unidentified microprocessor that does all the processing (yellow)
- Three NFETs driven by the microprocessor (red)
- The output to the LED strip (magenta)
- The 5 V supply to the logic chips. (cyan)
You may note a slight difference in the two boards shown above. The one on the left is a 2 layer board with capacitors, a LVR, and gate resistors. The one on the right is a single layer board that uses a resistor and a diode to achieve 5 V. It is actually kind of impressive that they were able to cut costs that much for the one on the right. I don’t know how well it will hold up long term, but if it does, good for them.
Unfortunately, neither voltage regulator setup is able to supply enough current to power an ESP or UNO chip, but both of these guys have FETS that will operate at 3.3V. (I leave it as an exercise to the reader to look up the FETs on your board and decide for yourself if it a good idea.)
Converting this board so that it is controlled by an external signal is fairly easy. First, remove the microprocessor. (the yellow guy) and then solder some leads onto the pads that go to the FETs. Then you just need to solder a lead to the ground, and (if you are going to use a DCDC converter to draw power from the same supply as the LED strip) another lead to the 12 V rail.
All that is left is to hook it up to whatever microchip you want to use to control it.