I love using slide potentiometers (a.k.a. faders) for this type of project, because at a glance you can tell how much of each color is selected. One problem that can arise, however, when using slide pots, is that they don't usually fit easily on a breadboard or perma proto board. These adorable little 35mm faders solve this problem! Since the bottom pin that is labeled "3" is the ground pin, all of the faders can share the common ground rail on the breadboard!
Each slide potentiometer will act as a voltage divider, with the Circuit Playground Bluefruit analog pins reading the wiper's varying output.
The pin assignments are as follows:
- Pin 1 = 3.3VDC
- Pin 2 = wiper (to analog input)
- Pin 3 = ground
Insert the three slide potentiometers into the breadboard as shown. You want the pin 3 legs of all three pots to be placed into the ground rail (next to the blue line).
Insert pins 1 and 2 so there is a free row of breadboard pins above them, this is where you'll make the wired connections to the CPB.
Use three small jumper wires (sometimes called "staples") to connect the pin 1 of each slide pot to the red +V rail of the breadboard as shown here. Looking from the top down, pin 1 is the pin on the left at the top of each slide pot.
Connections to Circuit Playground Bluefruit
Now we can use alligator clip leads with male header pins to connect the sliders to the CPB.
Insert the red lead into the breadboard's top red +V rail.
Insert the black lead into the breadboard's bottom black ground rail.
Insert the yellow lead into the left slider's pin 2 column on the breadboard.
Insert the green lead into the middle slider's pin 2 column on the breadboard.
Insert the blue lead into the right slider's pin 2 column on the breadboard.
Now, you can connect the alligator clips to the associated pads on the Circuit Playground Bluefruit:
- red to 3.3V
- black to GND
- yellow to A4
- green to A5
- blue to A6
You can now power up the Circuit Playground Bluefruit boards -- here I've used 3.7VDC LiPoly batteries plugged into the battery JST-SH ports. You can also use AA or AAA battery packs, or power over the USB port.
Remote Color Mixing
After a moment, the two boards will start up, and the mixer CPB will begin sending Bluetooth LE packets containing RGB color data based on the slider positions. The other CPB will listen for those packets and light up its NeoPixels in accordance with the RGB values.
Here you can see each slider used individually for pure red, green, and blue values, and then a mix of partial red and blue for a pink color. Try different combinations to mix your own colors!