It's interesting to hack one of your appliances or lighting projects into a whistle controlled intelligent one. The whistled allows you to do so by simply whistling two musical notes. To set it up、you just need to connect your 5.5/2.1mm DC connector on one end and your load on the other.
Specifications
ESD protected PCB、covered in transparent heat shrinkable tubing
Voltage must be between 4.5 and 18V at the input（barrel connector）
