Quick Facts:

Objectives:

Made for: Academic group project

Started: Spring 2021

Software: Autodesk Inventor, Arduino IDE, Tinkercad circuits

Hardware: Laser-cut wood housing, Arduino circuit with capacitive touch sensors, rotary encoders, and RGB LEDs

Existing light therapy boxes presented a number of problems for us. These included:

• Prohibitively expensive pricing
  
• Cumbersome controls
  
• Limited lighting functionality
  

Thus, I set out to design a light therapy box that:

• Can be built for less than $50
  

Challenges, Iterations and Lessons

This project presented a few challenges, namely that I:

• Had never designed a device intended for a medical purposes before
  • This meant that the project required heavy background research into light therapy and its effects on seasonal affective disorder
  • Research drove the decision to implement both a daylight-mimicking mode and a solid color mode
• Was working on a tight timeline to meet project deadlines
  • This meant that I had to use rapid prototyping to develop the enclosure and budget appropriate time for firmware development
    

Changes were made to the device during design to address issues including

• Dim LEDs
  • The 3 RGB LEDs used were the maximum brightness possible to implement without straining the Arduino Uno's onboard 5v power supply
    
  • These LEDs were not bright enough on their own to be seen through the diffuser
    
  • Metallic reflectors inspired by automotive headlights were added to the inside of the device to increase perceived LED brightness
• Under-performance of the daylight detection system
  • The system was intended to dim the onboard LEDs in dark rooms to prevent eye strain
    
  • This was deemed unnecessary on the current revision as the LEDs were not bright enough to pose a hazard
    
  • The feature was scrapped in firmware to meet the project deadline though the necessary hardware was fully implemented
    

Process Gallery

Circuit Design

The simulated circuit in Tinkercad

Technical Drawing

An exploded view of the enclosure

Firmware Creation

A section of the firmware in Arduino IDE

Test Fit

The assembled laser-cut panels

Enclosure CAD

A ray-traced render of the enclosure

Wiring

An internal view of the final iteration with the reflector

Final Assembly and Demonstration

Iterations, Results, and What I'd Do Differently

Results

Future revisions

After building this device, I

• Used it on my desk for blue light therapy and ambient lighting
• Enjoyed the benefits of stronger lighting in my apartment including general improvements in my mood
  
• Received high marks from my professor on the project
  

Version 2 of this device could include a

• Fully implemented daylight detection system
• Discrete power supply for more powerful LEDs
• More premium enclosure