Children's Plush Step Counter

Have you ever wondered if children have to reach a certain amount of steps per day just like adults do? Do they receive a sufficient amount of daily steps to maintain health and fitness levels?

Many children do not receive a healthy amount of physical activity throughout the day due to a lack of motivation, lack of awareness in both child and parent, lifestyle, and more. This is a problem as it can negatively impact health and increase the chances of early obesity and diabetes.

Surprisingly, children need more steps than adults do because they are still growing and need to burn off more energy. According to research studies, over 10,000-15,000 steps per day is the ideal requirement for a child whereas an adult would need 7,000-10,000 steps per day. As a result, I created a device designed to motivate children to exercise and help them obtain a healthy amount of steps per day, while also providing parents a way to track their child's physical activity.

This simple device is a wearable plush pig step counter made for children ages 6 years and up. It can be worn as a brooch, carried around, or stored in a pocket. When powered on, the screen displays the step count and a progress bar. As the device detects the wearer's steps and the step count increases, the progress bar fills up to a maximum of 10,000 steps.

The step counting device features:

1. The plush pig casing
2. An on and off power switch
3. A small 0.96 inch screen
4. Steps shown
5. Progress bar (10,000 steps max)
6. A brooch back bar pin on the back

The tools and components needed for this project:

Supplies and tools needed for prototyping phase

x1 400 Point Solderless Breadboard

x1 Set of Jumper Wire Cables

x1 0.96" OLED LCD Display (Pre-soldered

x1 ADXL345 Accelerometer (Pre-soldered)

x1 ESP32 Development Board (Pre-soldered)

x1 600mAh LiPo Battery

x1 3-pin Slide Switch

x2 Alligator Clips

x1 USB-C Data Transfer Cable

Supplies and tools needed for soldering phase

x1 Soldering Iron

x1 Rosin core soldering wire

x1 Heat Shrink Tubes

x1 Silicone wire roll

x1 Wire strippers & cutter

x1 Roll Electrical Tape

Supplies and tools needed for plush casing

x1 100% Undyed Wool Sweater (if you'd like to skip a couple steps, use pre-felted/pre-dyed wool fabric)

x1 2 Avocados

x1 Red Onion

x1 Pot of water

x1 Fabric Scissors

x1 Sewing needle

x1 Roll of White Sewing Thread

x1 Black and Brown Embroidery Floss

x1 Pen

x1 Sheet of Paper

x1 Handful of Filling

Stove top

Using jumper wire cables, wire the components as shown in the image above.

Here are the pin connections:

1. ESP32 to OLED Display
2. 3V3 -> VCC
3. GND -> GND
4. D21 -> SDA
5. D22 -> SCL
6. OLED Display to ADXL345
7. GND -> GND
8. VCC -> VCC
9. SCL -> SCL
10. SDA -> SDA
11. ESP32 to LiPo Battery
12. GND -> (-)
13. ESP32 to Switch
14. VIN -> Center terminal
15. Switch to LiPo Battery
16. 3rd terminal -> (+)

Note: when connecting the LiPo battery, snip the JST connector and strip the ends of the positive and negative wires of the battery. Use the 2 alligator clips to wire the battery to the switch and ESP32 development board.

I used these libraries shown as they are needed for coding with the components on the breadboard. The following code is used to "setup" or "prep" them for coding calibration and graphics.

With the USB-C data transfer cable, connect the ESP32 Development board from the breadboard to your computer. Open Arduino and upload this code. The OLED LCD display should turn on right away - this is how you know the wiring is correct. If the display does not turn on, check the wiring again and make sure there are no errors in your code.

Based on the connections shown on the breadboard, we now use silicone wire to make the connections between the components. Cut and strip silicone wire and wrap the wires around the pins. Solder carefully and make sure the pins next to each other are not soldered together. Because I am making a small children’s toy, I need the electronic components to fit compactly inside the pig plush casing I made.

To add extra security, use the heat shrink tubes and hover the soldering iron closely to shrink them. Lastly, add electrical tape to secure the connections.

First, prepare the dye bath by bringing a pot of water to a boil. Gather 2 avocados, a red onion, and a yellow onion. Take the avocado pits out of the avocados and wash it extremely well until there is no more avocado flesh left on them and dry them. This is extremely important because leftover avocado flesh can create a muddy dye bath. Once the water boils, add in the avocado pits and onion skins. Leave it to simmer for 2 hours. The longer you let the bath simmer, the darker the dye will be.

I used the fabric from a wool sweater that I had previously turned into felt by combining friction, heat, and moisture. I did this by putting the sweater into a washing machine with high heat and then into the dryer on high heat as well. This creates a more sturdy fabric. I took this fabric and pre soaked it in warm water for an hour. This ensures even dyeing.

Place the pre-soaked fabric in the dye bath for 10 seconds for a muted color. You can leave the fabric to soak even longer if a darker, more vibrant color is desired. Take it out, wash it well with a detergent and water, rinse, and dry the fabric.

I free-handed a pattern, keeping the electronic component measurements in mind. I drew out the pattern for the arms, legs, body, and ears. Cut it out to prepare for tracing the pattern on the dyed fabric.

Using a pen, I traced all of the cutouts onto the dyed fabric. I traced the body two times, the legs four times, the arms 4 times, the ears 2 times, and the tail once. I carefully cut out all of the parts to prepare for sewing.

Make sure to sew every component (the ears, body, arms, and legs) from inside out. Then flip everything out so the clean seams are visible. Sew the arms, legs, and ears onto the outside of the body.

Based on the measurements of my display, I cut an opening on the front of the body.

I cut out the pig’s nose and used the ladder stitch to sew it onto the head. Using black embroidery floss, I created the eyes by double knotting the thread and sewed them on. I also used dark brown embroidery floss to create the nostrils by knotting the thread once and sewing it onto the nose.

After the components are wired and soldered together, I carefully placed and arranged the electronics inside the plush pig casing.

From the inside of the pig plush case, I sewed the seams on the left side of the body, leaving the middle of the seam open. This will make sure the existing stitches don’t unravel when cutting the middle of the seam to make a hole for the switch. I cut out the stitches in the middle and carefully pulled out the switch from the inside. Afterwards, I added wool filling within the empty areas of the electronics to stuff the plush case.

After inserting the electronics and filling, I cut out a belly using wool felted fabric for the pig plush case. Using the ladder stitch, I joined the belly and the body together to enclose the electronics.

Next, I slowly cut a small square out to only show the display.

Lastly, I sewed a pin onto the back of the plush case to make the step counter easy to wear.