The 2x RGB LED strip DCC control hardware is finished.
The image shows the schematics to control one channel. The Arduino pwm output switches the gate of an NMOSFET. The FET switches the power, in our case the 12V of the LED strip. The resistor is there to keep the gate low, and the led’s OFF, when the Arduino is not powered. Six of these circuits are soldered on an Arduino experiment shield. They can be had for €1,25 over here.
Besides the FET’s and the resistors a few push buttons are included, which have the following functions:
A4 = push button for selection of RGB1 or RGB2 adjustment
A3 = push button for selection increase or decrease light output
A2 = push button for R adjustment
A1 = push button for G adjustment
A0 = push button for B adjustment
2×4 screw terminals are used to conveniently connect the LED strips and 2×2 screw terminals to connect the 2 power supplies. (LED strips often come with a power supply and to use only one of them will not deliver enough Amps, hence we simply connect one for each strip).