CH22-C - NeoPixel Rotate Speed

The magical thing about these “Individually Addressable” LEDs is that you don’t have to connect each LED to an individual pin on your micro:bit, you just need one signal wire along with power (Positive and Negative) to light things up.

So let's get connected! If you turn the NeoPixel Strip over you'll see labels for the three pins. You should see IN, VCC, and GND.

Use the Crazy Circuits Ribbon Cable to connect the NeoPixel Strip to the Bit Board.

The end with S1, +, and - can plug directly into the Pin 13 row (make sure S1 goes into 13) and the other end should plug into the NeoPixel Strip as shown.

We only need three wires for the NeoPixel Strip so you can leave S2 (the Orange wire) unconnected.

We'll also connect a button using Maker Tape. Connect it to Pin 5 and GND. (Polarity does not matter with these buttons.)

To mount the NeoPixel Stick in place we used our NeoPixel Beam Holder with a long Technic Beam and two 1x1 LEGO bricks.

You can always use rubber bands, tape, or some other method.

The important thing is to make sure the connector is on the left hand side so the number index for the NeoPixel strip makes sense.

If you've never used a micro:bit before you'll want to check out this guide: Bit Board V2 Setup and Use

We're going to load the following code for our NeoPixel Rotate Speed program: https://makecode.microbit.org/_ebzKmh61i...

We will once again check for a button press and if we see one we will toggle between two different delayTime values. (We'll also pause after as a primitive debounce mechanism.)

A second forever loop call our pixelMover function, passing in the delayTime.

Finally, our pixelMover function runs and a pixel is rotated with the delay we've set between each move/rotation.

Once the code is loaded it should start running immediately.

You can power the micro:bit via the USB cable you used to load the code or you can use a battery pack plugged into the Bit Board.

You'll see the pixel move from left to right at a slow speed.

Press the button down and the pixel should speed up! Press it again to slow it down.

Things may or may not work as expected depending on how long the button is held down. We covered some more advanced button behavior in Chapter 4 - Single Button.

See CH4-D - Button Toggle Better for a good "toggle" example.

Follow along with our recorded Live Stream!

You can watch the full video of us walking through this project, along with explaining and exploring the code: https://youtube.com/live/8EJiYAkb8qk