You will need:

• Pico and Breadboard
• 8 M2M Jumper Wires
• 3 M2F Jumper Wires
• 5 NeoPixel LEDs
• 1 Rotary Potentiometer
• 1 Slide Potentiometer

The LEDs you are using are special because they can shine in any color that you program to! They are called NeoPixels.

NeoPixels are actually 3 different LEDs (1 red, 1 green, and 1 blue) and a special chip all packed in a single package. In fact, if you were able to break open a NeoPixel and look at it under the microscope, this is what you would see:

You probably also noticed that the NeoPixel has four leads instead of the the normal two. That's because it need two for power and ground, just like any other LED, but it needs one lead for a data in signal, and another to send data out to the next NeoPixel:

Repeat this process for each of the remaining NeoPixels. Remember that the output of one NeoPixel connects to the input of the next Neopixel.

Then, use a jumper wire to connect the input of the first NeoPixel's Input to GP15.

Next, connect the top power rails. Use a jumper wire to connect the top ground rail to a ground pin on the Pico. Use another jumper to connect the top positive rail to 5V.

Click NEXT.

Do you remember doing the Resistor Piano tutorial? In that tutorial, you learned about voltage dividers. A potentiometer can be wired up in the same way, and it can become a voltage divider!

Notice that both potentiometer's have three connections. The middle connection on the rotary potentiometer, and the one labeled OTA or OTB is connected to the potentiometer's wiper. The wiper makes contact with a resistive material like carbon or graphite - which acts like a resistor. Depending on where along the length of the resistive material the wiper makes contact, the resistance changes.

Ready to connect the potentiometers to your circuit? Click NEXT.

First, use a jumper wire to connect the bottom ground rail to another ground pin on the Pico. Connect the bottom positive rail on the breadboard to the 3V pin on the Pico.

Then, place the rotary potentiometer somewhere in the bottom half of your breadboard. Pay attention to which 3 columns the leads of the potentiometer plug into. Then, use a jumper wire to connect the rightmost lead to the positive rail on the bottom of the breadbaord. Connect another jumper from the leftmost lead to the ground rail on the bottom of the breadboard. Finally, connect a jumper wire from the center lead of the potentiometer to the A0 pin on the Pico.

Now that our potentiometers are connected, let's build some code that we can use to test them.

Grab a start block from the Chip menu and place it onto the workspace. Then, grab a repeat forever block from the Loops menu and connect to the start block.

Next, grab a graph block from the Actions menu and place it into the repeat forever block. Click the Blue Gear Icon on the graph block. In the mini-workspace that opens up, drag a value block into the send block so that there are two blocks inside of it. Click the blue gear icon again to close the mini-workspace:

Grab a read voltage from block from the Chip menu and place it into the first input of the graph block. Grab another read voltage from block from the Chip menu and place it into the second input of the graph block. On the second read voltage from block, change the pin to A1:

Now that we have tested the potentiometers, let's test the NeoPixels.

First, grab the graph block in your program and drag it to the trash.

Next, grab the setup neopixels block from the Actions menu and connect it between the start and the repeat forever blocks. Change the pin to 15, and set the number of pixels to 5:

Grab a set all neopixels to block from the Actions menu and place it inside the repeat forever block. Grab the color block that is inside of the set all neopixels to block and drag it to the trash can to delete it. Grab a random color block from the Values menu and place it inside the set all neopixels to block. Finally, grab a update neopixels block from Actions and connect it below the set all neopixels to block:

Before you click START - be careful not to stare directly into the NeoPixels - they can be VERY BRIGHT!
Click START to run your test program. Do the NeoPixels flash different colors every 0.5 seconds? Awesome!

Once your NeoPixels are working, click STOP.

But wait! Why are the NeoPixels still on? NeoPixels will stay on the last color that the Pico sent to them. One way to turn them off is to send them a black color using the color block from the Values menu:

The color hue block will turn a number value into a Hue. Let's try it out!

First, let's turn the Digital View off by clicking the DIGITAL VIEW tab at the bottom of the workspace to open it. Then, click the toggle switch on the left side of the digital view to turn it off. Then, click the DIGITAL VIEW tab again to close it.

Why did we just do that? When the digital view is running, it slows the Pico down a little, and it can actually slow down your computer too, because the computer has to listen for messages from the Pico.

Our next task to to make a variable that will hold the value that we will turn into a color. Click the Variables menu, and then click Create variable.... Name your new variable "knob value". Then grab the set knob value block and place it at the top inside of the repeat forever block:

Since we know we need to map the value from the rotary potentiometer to a new value between 0 and 255, we'll need a map value block.

Grab a map value block from the Logic menu and place it into the first input of the map value block. Set the from range to 0 : 3.3. This is because the voltage that can come from the potentiometer will be between 0 and 3.3V.

Then, change the to range to 0 : 255. Grab a read voltage from block and place into the empty input of the map value block. Set the pin to A1:

Next, grab the color block inside of the set all neopixels to block and drag it to the trash can to delete it. Grab a color hue block from the Values menu and place it where you just removed the color block from. Grab the 0 block from inside the color hue block and drag it to the trash can to delete it.

Next, grab a knob value block from the Variables menu and place it into the color hue block. Then, set the wait time of the repeat forever block to 0:

Now that we can make any color we want, let's try making a rainbow chase! A rainbow chase is where we set each light to a different color, and then make the lights look like they are "chasing" each other. It's a really cool effect, and it's not too hard to do!

The first thing we need is a list to store 5 different colors in, and we need a variable to hold that list.

Click the Variables menu and then click Create variable.... Name your new variable "color list". Grab the set color list to block and connect it right below the setup neopixels block near the beginning of your program.

Grab a create list with block from the Lists menu and place it into the set color list block. Then, click the blue gear icon to open the block's mini-workspace. Drag and add two more item blocks in the mini workspace so that you have a total of 5, and then click the blue gear icon to close the mini-workspace:

Now we need to fill our list with colors. Grab a 0 block from the Values menu and place it into the first input of the create list with block. Do this again 4 more times to fill all of the inputs of the create list with block.

Set the 0 block's value to 0. Set the next one's to 50, the middle one's to 100, the next one's to 150, and the last one's to 200. Why these values? The range of values you can put into the color hue goes from 0 to 255. If you divide 255 by 5, you get 51. 50 is close enough, so that is why each value is 50 more than the next!

Click the set all neopixels block so that it is highlighted (there is a yellow ring around it) and press your "delete" or "backspace" key to delete that block.

Grab a count with block from the Loops menu and place it into our program right before the update neopixels block. Change the 10 in that block to a 5.

Then, grab a set neopixel block from the Actions menu and place it inside the count with block. Delete both of the blocks that are inside of the set neopixel block:

Grab an i block from the Variables menu and place it into the first input of the set neopixel block. Then, grab a color hue block from the Values menu and place it into the second input of the set neopixel block.

Delete the 0 and 100 blocks from the color hue block by dragging them to the trash can. Then, grab a in list block from the Lists menu and place it into the hue input of the color hue block. Grab a slide value block from Variables and place it into the brightness input of the color hue block:

Grab a color list block from Variables and place it into the first input of the in list block. Then, grab another i block from Variables and place it into the second input of the in list block:

Let's try it out! Click the START button. If it's working, each of the NeoPixels will glow a different color, and we can use the slide potentiometer to adjust their brightness.

They aren't "chasing", though...how do we make them chase?

We are going to use a rotate list block! When you rotate a list, you take the value from one end and attach it to the other, and shift all of the other items in the list. You can rotate left or right. The image below shows what happens to a list when it is rotated 1 position to the left:

Let's make another list. This list is going to hold our sounds. We also need a variable to hold our list.

Click the Variables menu and then click Create variable.... Name your new variable "sound list".

Right-click the set color list block at the beginning of your program and select Duplicate. Connect the new blocks right below the first set color list block. Then change the variable in that block to sound list. Delete the 50, 100, 150, and 200 blocks in that block's create list with block by dragging them to the trash can (leave the 0 block in the list). Next, grab a drumkit block from the Sounds menu and place it into of the inputs of the create list with block. Do this again for all of the empty inputs. Then, pick a different option for each drumkit block:

Grab an if _ = _ do block from the Logic menu and connect it after the set color list block at the end of your program. Grab an in list block from the Lists menu and place it into the first input of the _ = _ block. Change the # in the in list block to first. Then, grab a sound list block from Variables and place it into the input of the in list block. Change the = in the _ = _ block to ≠ (not equal). Then, grab a 0 from Values and place it into the right side of the _ ≠ _ block.

This will make it so that when it gets to the 0 in our list of sounds, it will just not play a sound. That means we can have "rests", which make our beats sound better!

Grab a play sound block from the Sounds menu and place it inside the if do block. Right-click the in list block in the if do block and select Duplicate. Place the new blocks in the input of the play sound block.

Right-click the set color list block right above the if do block and select Duplicate. Place the new block after the if do block. Change the variables in the new blocks (both of them) to sound list. Then, change the 1 in the left by input to -1: