A STEM Project: Using a Brown Dog Bit Board With A Microbit to Rotate a Christmas Carousel

Using a Brown Dog Bit Board With A Microbit to Rotate a Christmas Carousel

The Microbit has a limited power supply of 3 volts. Motors that are powered by the Microbit, do not run well or not at all because of the limited power draw. I used a Brown Dog Crazy Circuits Bit Board. https://www.browndoggadgets.com/products/crazy-circuits-bit-board to expand the capabilities of my Microbit to use a continuous rotation 360 degree servo https://www.browndoggadgets.com/products/brick-compatible-360-degree-servo

Using the Christmas Carousel that I designed in this posting, https://papercraftetc.blogspot.com/2020/11/a-christmas-carousel-with-color.html I added a Lego axle to the center column to attach it to a continuous rotation 360 degree servo to make this carousel move.

Here is a video of the Carousel in action.

Programming The Microbit

Here is the program that I used to operate my Microbit,

https://makecode.microbit.org/S93920-16424-99319-86020

The program does a few things.  It streams the message "Happy Holidays" across the LED display. When the left button is pressed, the song "Deck the Halls" plays and the carousel rotates clockwise. When the right button is pressed, the carousel stops rotating.

Connecting the Microbit to the Brown Dog Bit Board

The Microbit is connected to the Brown Dog Crazy Circuits Bit Board as shown above.

I boxed in the battery power supply with Legos and added a glue dot to the bottom of the battery compartment so that the battery would not move around.

The battery is connected with the red and black wires to the bit board at the red connector, shown above in the middle of the photo. The red wire is positive and the black wire is negative. I recommend using new batteries as I experienced problems with my servo while using old batteries.

The continuous rotation 360 degree servo is connected via the orange, red and brown wires to the bit board at the location of pin 0. The colors of the servo wires correspond to the colors of the pins. Check to make sure the servo works before continuing to attach the carousel.

Connecting the Carousel to the Continuous Rotation 360 Degree Servo 

I attached the carousel with a Lego axle and two gears to add stability at the point where the axle and the servo meet.  There is a little wobble as the carousel rotates.  The wobble is more apparent at higher speeds.  At a 50% running rate, the wobble is very slight.