The code presented on this page can be downloaded or found in the Arduino examples menu under Examples → SpinWearables → Dancing_with_Color → 1D_Rotation_Light_Up_Advanced.

Dancing with Color: Color changes based on direction.

In this example, we will step through the code used to make the SpinWheel change color based on the direction of the spin. For more information and previous examples, refer to the dancing companion page.

These include statements should look familiar! As a reminder, they allow the program to access coding tools for the SpinWheel.

#include "SpinWearables.h"
using namespace SpinWearables;

The setup function should also seem familiar. As a reminder, the setup function is run once when the SpinWheel turns on. Also, SpinWheel.begin() prepares the LED to accept new colors.

void setup() {
  // Initialize all of the hardware on the SpinWheel.
  SpinWheel.begin();
}

Here, we initialize two variables, one to tell the SpinWheel what color to display when the device is spun in the positive direction and the other for the negative direction.

int pos_spin = 0;
int neg_spin = 0;

Instructions in a loop function are repeated over and over again, in other words, “in a loop”.

void loop() {

The readIMU function checks if the sensor is ready and takes its current rotation data.

  SpinWheel.readIMU();

Here, we will also utilize else if and else commands. These commands are used in programming along with an if statement to tell the program what to do when the if condition is not met. In this example, our if condition checks whether or not the rotation is big enough in the positive direction. If this condition is true we will light up the LEDs according to the given instruction. Feel free to play around with this number.

  if (SpinWheel.gx > 100) {
    pos_spin = 255;
    neg_spin = 0;
  }

If the rotation is not big enough in the positive direction, we will use an else if command to see if the spin is large enough in the negative direction. If it is, then we will follow the given instruction.

  else if (SpinWheel.gx < -100) {
    neg_spin = 255;
    pos_spin = 0;
  }

If all previous conditions are not true, then we will use an else command. In this case, if the rotation is not large enough in either direction, the SpinWheel will not light up.

  else {
    pos_spin = 0;
    neg_spin = 0;
  }

As before, the setLargeLEDsUniform function tells the SpinWheel to show the color we would like it to show. Based on the previous if statements, if the device is spinning in the positive direction, the LEDs will light up green. If the device is spinning in the negative direction the LEDs will light up blue.

  SpinWheel.setLargeLEDsUniform(0, pos_spin, neg_spin);

  SpinWheel.drawFrame();
 }