Techno-Shirt

Test Your LEDs

Before you start, it is a good idea to test each of your NeoPixels.

  • Open the Arduino IDE. Make sure the correct device is selected in the Tools menu. I’m using the Flora, so for me it’s Adafruit Flora.

  • Go to the File menu, select Examples, then find Adafruit NeoPixel (it may be at the very bottom!) and choose strandtest.

A code file will open. A code file is called a sketch in the Arduino IDE.

  • Find this line of code near the top:
Adafruit_NeoPixel strip = Adafruit_NeoPixel(60, PIN, NEO_GRB + NEO_KHZ800);

  • Change the first number to 1. The line should look like this now:

    Adafruit_NeoPixel strip = Adafruit_NeoPixel(1, PIN, NEO_GRB + NEO_KHZ800);

  • Click File and then Save As…. Type in a name for your sketch and click Save.

  • At the top of your sketch, click on the tick (the check mark) icon to verify the code. At the bottom of the window you should see the words “Done Compiling” which means the code compiled successfully (if not, you will see errors printed here. To fix these, you will need to do some debugging and change your code!).

Ready to upload!

  • Plug in your Flora. Press the reset button on the Flora and then straight away, while the red light is pulsing, click on the arrow icon next to the tick/check mark to upload the code onto the board.

  • You should see the red light flashing, followed by two orange lights on the board. When it’s finished, you should see the words “Done uploading.” at the bottom of your sketch.

Problems with uploading

At first it can be a bit tricky to get the upload to work. Make sure the correct board is selected and that you have a working USB cable that’s plugged in properly on both ends. After that, it’s all about timing! You’ll get the hang of it.

  • Unplug the Flora from your computer (You can use the power switch on a Flora to turn it off when you’re using a battery pack, but it does not work when the board is plugged into a computer via USB).

It’s important to always unplug or switch off the board before connecting or disconnecting other components so that you don’t damage them!

  • Attach three crocodile clips to the board’s GND, #6, and VBATT pins.

  • Take a NeoPixel and connect the board’s GND wire to its – pin. Connect the board’s #6 pin to the data in pin: this is the pin with an arrow pointing in towards towards the LED in the centre. Finally, connect the board’s VBATT to the + pin.

  • Ready? Plug in the Flora once more and watch your LED start to light up and flash a multicoloured sequence!

  • Test each of your other NeoPixels one by one by connecting them up to the Flora as you’ve just done with your first one. Remember to unplug the Flora before connecting or disconnecting any wires!

  • Once you’re done with testing the NeoPixels, change the code again to the total number of NeoPixels you’ll be using. Mine is eight:

Adafruit_NeoPixel strip = Adafruit_NeoPixel(8, PIN, NEO_GRB + NEO_KHZ800);
  • Click Verify, and then upload the new code onto the Flora. Next you’re going to make your NeoPixel circuit!
< Next