LEGO-compatible Elements

To build the winder you'll need a particular set of LEGO-compatible elements, either raid your collection or grab the .csv part list linked below and order parts from LEGO Pick a Brick, Brick Owl, or a similar site.

You can also use this link to order parts from a seller on Bricklink.

Build Instructions

You can follow the instructions in the .pdf linked below to create the winder's brick assembly.

Motor Prep and Wiring

Fit the motor axle adapter onto the motor shaft -- either side is fine.

Then, screw the motor wires into the two Crickit motor terminals marked "1" as shown. The order doesn't matter.

Gearbox

The TT motor spins a bit fast, so we'll gear it down to decrease speed and increase torque.

Once assembled as shown you can adhere the motor to a 2x4 tile using double-stick foam tape.

Watch Holder

Using the .pdf instructions as your guide, build the watch holder. This will allow you to strap most any size watch to the wheel and insert it in the open frame so that it will rotate in the proper orientation.

Tiles

Continuing on with the .pdf instructions, add tiles to the exposed studs for a nice clean finish. You'll leave a plus shaped section exposed to mount the Crickit and Circuit Playground Express.

Crickit Mount Plate

Follow the instructions in this guide to 3D print the Crickit mounting plate that adapts it to LEGO-compatible tubes.

Then, add four 2x4 bricks as shown. These simply press together to connect, relying on clutch power to stay in place like any regular brick.

Crickit Connection

Use four M3 x 6mm standoffs and eight M3 x 4mm screws to fasten the Crickit to the mounting plate.

Add Watch

To add the watch simply strap it around the wheel and then squish-fit it into the holder frame as shown here.

MakeCode for Circuit Playground Express

In a WebUSB capable browser, such as Chrome, launch the MakeCode Circuit Playground Express editor by clicking this link. 

Add Crickit Extension

Click the Advanced button, and then click on Extensions.

This will open the Extensions page, click on the Crickit extension at the bottom to add it to your Makecode editor.

Crickit Category

You'll see that the Crickit category has now been added to your block palette.

Setup

You'll start with NeoPixel LED setup and by creating variables. These go in the on Start loop block.

The NeoPixel blocks come from the Light category.

Create the variables in the Variable category. To make time easier to track, you'll make a second variable equal to 1000 milliseconds, and then a minute variable equal to second * 60 using the multiplication block in the Math category.

You can then create a turn_time variable to around 14 seconds (enough for two turns of the watch) using a multiplication block, and the pause_time of around 4 minutes.

Direction Switch

You can use the slide switch on the Circuit Playground Express to determine the direction the winder turns.

From the Input category, grab one each of the on switch moved left/right blocks.

Use the dropdown menu to pick left for one and right for the other. In the left block add a crickit set motor 1 inverted OFF block. This will cause the motor to turn the watch counter-clockwise.

For the right block, set this to ON to turn clockwise.

You will also use set pixel color blocks from the Light category as shown to change the two bottom NeoPixels to indicate direction visually.

Start/Stop Button

Use an on Button A click block from the Input category to start and stop the winder.

A set run to not run block from the Variables category toggles the value of the run variable.

Then, an if run then...else block from the Logic category set the pixel 0 color to green or red depending on the state, and uses crickit stop motor 1 to stop the motor from turning.

windWatch Function

In the Advanced section, from the Functions category, create a new function called windWatch.

This is what will be called any time the run variable is True in the main Forever loop.

The function will set pixel color at 9 to cyan to indicate the motor is running, then set the cricket run motor 1 to 100%.

Next, it will pause for the turn_time.

Then, pixel color at 9 is set to orange to indicate the motor is paused.

crickit stop motor 1 stops the motor from turning, and then pause pause_time will keep the motor paused until it is time to start the function loop all over again, so long as run is True.

forever Loop

Get a forever loop from the Loops category. in it an if run then block from the Logic category is used to call the windWatch function. If the button A is pressed to toggle to off, then run is False and this function won't be called. Press button A again to make run True and the function will be called.

How to Wind a Watch Automatically

Here's the fun part! With the watch mounted, plug in the Crickit to a 5V 2A (or higher) power adapter or battery pack.

Turn on the Crickit by flipping its on/off switch.

The Circuit Playground Express will show that it is in standby mode by first displaying a yellow NeoPixel LED. To start it, press button A (the Circuit Playground Express button on the left side).