TfCD Smart Stress Ball

Introduction: TfCD Smart Stress Ball

Stress is one of the key issues people face everyday at study or work. It is often caused as a result of over working and exhaustion and for sometimes it becomes overwhelming beyond the capacity of the person. Such people not only tend to lose concentration over time but also have their health adversely affected.

As part of TfCD assignment at Industrial Design Engineering of TU Delft, I and my friend, Stefan Lorist have come up with this idea of a Smart Stress Ball based on Arduino. Its based on the concept of effect of colors on people (popularly used in Mood lights nowadays).

The Ball prompts the user with a vibration use cue and flashing red LED as visual cues reflecting stress. When the user, pressed the ball for a minute, the LED color changes to a slow pulsating blue light indicating that the user is relieving his stress while finally the green color indicates to the user that he/she has de-stressed enough and he can get back to work.

Step 1: Build the Circuit

The stress ball is powered by an Arduino UNO. You can find the code in the next step

Materials Required:

1x Arduino UNO

3x 220 Ohm resistors

1x 3.3k Ohm resistors

1x 1k ohm resistor

1x 22n Capacitor

1x PNP transistor

1x Vibration motor

1x Switching Signal 1N4148 Diode

1x Breadboard


1x Force Sensing Resistor (FSR): Range 100g- 10kg (0.5" diameter)

17x Jumper cables

Step 2: Copy the Code

Copy the code from the above txt file

Step 3: Making the Ball

1. Cut out a ball from a block of Styrofoam with a heated string or blades. Be careful with the hot strings. You could burn your skin if it slips.

2. It is not easy to create rounded cut edges with the hot strings, so use a sand paper to smooth the surface

3. Using the same method as above, slice the ball midway but not entirely. This will keep the ball intact but still press-able.

Step 4: Finishing Up

1. Insert female jumper cables to the inner edge of the ball cut. This shall also act as the fulcrum/ support while pressing the ball

2. Insert the RGB LED into the jumper female pins

3. Insert the FSR sensor and Vibrator Motors into the balls. Preferable position the sensor near the mouth of the cut

Step 5: Yayy ! Its Done :)

Step 6: Testing



    • Fix It! Contest

      Fix It! Contest
    • Metalworking Contest

      Metalworking Contest
    • Tiny Home Contest

      Tiny Home Contest