The code presented on this page can be downloaded or found in the Arduino examples menu under Examples → SpinWearables → Animations_and_Patterns → Simple_Blink.
In our animations and patterns lesson we describe how an animation can be created by instructing a computer to make a particular drawing dependent on a single number, the current time. This is a small example doing exactly that: We read the current time, divide it in intervals, and depending on the time since the start of the last interval, we change the brightness of the LEDs.
Most of our code examples start with these include statements, as they tell the computer that there is a set of coding tools related to the SpinWheel that we will want to use.
#include "SpinWearables.h"
using namespace SpinWearables;The instructions we write in the setup block are executed once when the SpinWheel device powers on. We run one single instruction called SpinWheel.begin() which prepares all the LEDs to accept new colors.
void setup() {
SpinWheel.begin();
}The instructions in the loop block are executed repeatedly “in a loop”. This is what lets us smoothly update the brightness of the LEDs and make a simple animation.
void loop() {First we store the current time in the variable t. The function millis() gives us that time.
int t = millis();Then we divide the time in equal intervals of length 2.5 seconds (2500 milliseconds). By performin division with remainder and storing only the remainder, we find the time since the last interval has started. In this computer language a / b means “divide a by b”, while a % b means “find the remainder after dividing a by b”. We store this time in t_repeating.
int t_repeating = t % 2500;t_repeating will now smoothly go from 0 to 2500, and then repeat. We want to turn this number into a brightness for each color, but the SpinWheel does not permit color settings higher than 255. Thus we divide t_repeating by 10 and store the result in the variable b.
int b = t_repeating / 10;Finally, we use the setLargeLEDsUniform function, which takes three numbers (a red, a green, and a blue intensity) and sets all of the large LEDs uniformly to the given color.
SpinWheel.setLargeLEDsUniform(b, b, b);
SpinWheel.drawFrame();
}