CH21-D - NeoPixel Shift RGB Back

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.

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 Shift RGB Back program: https://makecode.microbit.org/_ie58JHe0m...

The shift function sends pixels down a string as the number index keeps increasing.

In this example we've set our code to shift 5 times, then clear and do another shift sequence, but this time we shift negative (using -1) to send the pixels back the other direction.

The shift function (as well as the rotate function, which we'll see in other guides) can be a bit complex, but we'll explore them in the next few chapters.

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 should see red, green, and blue pixels shift all the way to the right (5 positions) and then shift back all the way to the left (5 positions.)

Why do we shift 5 positions? Because with 3 lit up pixels we then fill the 8 pixel wide strip!

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/0AHEZyJg4M0