CH12-B - Potentiometer LED Bright Reverse

We'll use Maker Tape to connect the Potentiometer and LED to the Bit Board on a LEGO baseplate.

The LED will connect to Pin 8 and to Ground (GND) BUT! We're going to use the "gutter" between the LEGO baseplate studs so we can have two layers of tape that do not touch.

See the photos to show how this works. It's a technique we'll use for certain projects. It can also be used when you're tight on space for tape paths.

Once the LED is connected we'll need to connect the Potentiometer. One side goes to Ground (GND) and the other side to 3.3v

We will then connect the center of the Potentiometer to Pin 0. (Note that Pin 0 is an analog pin.)

You'll notice the Ground on the Bit Board is color coded White.

The 3.3v hole on the Bit Board is labeled and is actually two holes right next to each other on the Bit Board. (There is a small line showing the connection between them.)

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 Potentiometer LED Bright Reverse program: https://makecode.microbit.org/_deaaHi7Ke...

Our code is (again) pretty simple! We'll first turn off the built-in led because we don't need it, then we'll forever loop an analog write to Pin 8 (which is where we connected the LED) and set the value we get from the Potentiometer connected to Pin 0.

The Potentiometer provides a value between 0 and 1023, and the LED can accept a value between 0 (off) and 1023 (full brightness) but this time we'll use the map function to reverse the values, so anti-clockwise makes the LED brighter and clockwise makes it dimmer.

We'll add one more trick to our code. If the (mapped) value from the Potentiometer is less than 20 we'll set it to zero.

Our little trick will help solve the issue of the Potentiometer not going all the way to 1023 sometimes.

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.

Turn the small blue knob on the Potentiometer and you'll see the brightness of the LED change.

Turning fully anti-clockwise should make the LED so very bright and turning the knob fully clockwise should make the LED dim enough to appear off.

Remember that we're going to set the LED output to 0 (zero) if the mapped Potentiometer value is below 20.

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/1FlnatERZ94