Techno-Shirt

Flashing Lights

  • Create the following new function after your first one:
void lightAllOneColour(uint32_t c) {
    strip.setPixelColor(0, c);
    strip.setPixelColor(1, c);
    strip.setPixelColor(2, c);
    strip.setPixelColor(3, c);
    strip.setPixelColor(4, c);
    strip.setPixelColor(5, c);
    strip.setPixelColor(6, c);
    strip.setPixelColor(7, c);
    strip.show();
}

What’s inside the round brackets?

This function takes a parameter: that’s the bit inside the round brackets. It’s some extra information that you give the function when you call it.

  • This time you will write your function calls in loop instead of in setup. Click inside the loop function and add code so that it looks like this:
void loop() {
    lightAllOneColour(strip.Color(0, 0, 255));
    delay(200);
    lightAllOneColour(strip.Color(0, 0, 0));
    delay(200);
}

How the parameter works

See how you’re passing in a colour as a parameter to your lightAllOneColour function? This is the colour that gets used in place of c on each line inside that function. It means you can use the same function to make the NeoPixels any colour, and you can even turn them all off!

  • Delete the line lightAll(); from inside the setup function. Verify and upload the code.

About the setup and loop functions

When the Flora turns on, it runs all the code in the setup function first, and then it runs the loop function over and over again forever!

  • What do you think the delay function does? Try putting in different values for its parameter, for example delay(50); or delay(1000);. Don’t forget to verify and upload the code to test out your changes!

  • Have you noticed that the colour (0, 0, 0) turns the pixels off? Try running the following code on the Flora:

void loop() {
    lightAllOneColour(strip.Color(255, 0, 255));
    delay(500);
    lightAllOneColour(strip.Color(0, 0, 0));
    delay(500);
    lightAllOneColour(strip.Color(255, 127, 0));
    delay(500);
    lightAllOneColour(strip.Color(0, 0, 0));
    delay(500);
}
  • Now run the same code without the “off” colour:
void loop() {
    lightAllOneColour(strip.Color(255, 0, 255));
    delay(500);
    lightAllOneColour(strip.Color(255, 127, 0));
    delay(500);
}

  • Do you see the difference?

  • Try designing your own sequence by changing the code in the loop function! You can add as many delays and as many calls to your lightAllOneColour function as you like. Experiment with longer and shorter delays and different values for the colour parameter.

Remember, the whole sequence will keep repeating over and over if you put your code inside the loop function.

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