For a personal project I designed a super tiny Wifi dimmer module, based on the ESP8266. It doesn't need any arduinos or rasp pis to work, just the ESP.
This is an attempt to make a module with correct pulldown/ups that minimizes wasted power consumption, all in a 2x3cm package. Its height is incredibly small too, causing it to be integrable almost anywhere. Just hook up a power supply and a LED strip, and enjoy having your lighting dimmable from any device.
After playing around with the idea of an RGB version of the original model, I've finished a design that has 3 channels instead of the 1 present on the original.
This means you can now control RGB LED strips over WiFi for < $5!
The overall design has been improved, resulting in beefed up current ratings amongst others. You can now draw 8.5A per channel! That means you can hook up 306 Watts of LED strip awesomeness, pretty cool.
Assembling this baby should be easy enough for anyone who has hand soldered a couple of times before. First up is the PCB itself. It comes panellised into two modules per board, so break one in half.
Next, we put the 12V -> 3.3V DC converter in place. I did this by first applying some solder on the 8 pads on the back. If you've not used solder flux paste before, try it. Seriously. Putting some flux on the pads before soldering makes your life a million times easier.
Then, I placed the converter on top (be sure to check its orientation! In this picture the part with the chip goes in the top). I then aligned it with the solder balls, heated up one of its pin holes, added a small amount of solder onto the pin hole, and let the solder seep through to the solder ball beneath it. Repeat this for all holes.
After that, I made sure that the converter was set to the right voltage. These converters are configured to pass on 12V by default, which would kill the ESP8266 chip immediately if found out too late.
The output voltage can be adjusted by turning the screw on the lower left side.
Because the screw terminal blocks hadn't arrived yet when I was putting this one together, I soldered the 12V power supply directly to the board:
I plugged in the power supply, and measured the voltage across the ESP vcc and gnd pads. In order to reach the vcc pad, I sanded the part where the PCB was broken in half down a bit.
After setting the output voltage to roughly 3.3V (I tend to give it a bit more, 3.5 is still within the ESP's specs), unplug the power supply again to make sure you can't short anything during soldering.