NATHAN'S SCIENCE EQUIPMENT ADJUSTER

Key Concepts

Smart Servo Technical Principles

The Smart Servo combines electronic control (through the Adafruit Trinket M0 microcontroller) with mechanical motion (via the MG956 servo motor). Understanding the relationship between input signals and physical movement is essential for designing effective assistive technology.

Input-Process-Output Framework

All technology solutions follow an input-process-output framework:

• Input: Button presses, switch toggles, or other user actions
• Process: Code that interprets inputs and determines appropriate responses
• Output: Servo movement and LED feedback

Human-Centered Design Process

The design process must focus on Nathan's specific needs rather than starting with the technology. This includes:

• Empathizing with Nathan's experience
• Defining the specific problem to solve
• Ideating multiple possible solutions
• Prototyping the most promising ideas
• Testing with users and iterating based on feedback

Activity: "Problem Definition and Initial Design"

1. Problem Statement Development:
   • Guide students in developing a clear problem statement based on Nathan's needs
   • Use the HCD Tool 1.2 (Problem Statement) framework to create concise descriptions
2. Requirements Analysis:
   • Help students break down the problem into specific requirements
   • Categorize requirements as "must have" vs. "nice to have"
   • Identify specific constraints (size, weight, operation force, etc.)
3. Initial Solution Sketching:
   • Have students sketch at least three different design concepts
   • For each concept, identify which requirements it addresses and how
   • Include annotations about materials, servo placement, and user interface

Extension Activity: "Prototype Development"

1. Design Selection:
   • Have students use a decision matrix (HCD Tool 3.2) to evaluate their design concepts
   • Guide them in selecting the most promising concept to prototype
   • Refine the chosen design based on feasibility and alignment with requirements
2. CAD Modeling:
   • Introduce basic OnShape CAD modeling for designing mounting brackets or adapters
   • Guide students in creating simple 3D models for any custom parts needed
   • Prepare files for 3D printing
3. Physical Prototype Construction:
   • Assemble the Smart Servo with LocLine connectors and mounting hardware
   • Integrate the selected input device (button, switch, etc.)
   • Construct any necessary fixtures or mounting solutions
4. Programming Implementation:
   • Develop the control program for the servo based on the design requirements
   • Implement appropriate feedback through the Neopixel LED
   • Test and refine the code to ensure smooth operation

import time
import board
import neopixel
from digitalio import DigitalInOut, Direction, Pull
import pwmio
import servo

# Set up button on pin D2
button = DigitalInOut(board.D2)
button.direction = Direction.INPUT
button.pull = Pull.UP

# Set up Neopixel on pin D1
pixel = neopixel.NeoPixel(board.NEOPIXEL, 1, brightness=0.3)

# Set up servo on pin A2
pwm = pwmio.PWMOut(board.A2, duty_cycle=2 ** 15, frequency=50)
my_servo = servo.Servo(pwm)

# Define positions for fine adjustment
positions = [0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180]
position_index = 0

# Set initial position
my_servo.angle = positions[position_index]

# Show initial status with LED
pixel.fill((0, 0, 255))  # Blue = ready/idle

while True:
    # Check if button is pressed
    if button.value == False:
        # Visual feedback during button press
        pixel.fill((255, 165, 0))  # Orange = processing
        time.sleep(0.2)  # Debounce delay
        
        # Move to next position
        position_index = (position_index + 1) % len(positions)
        
        # Update servo position
        my_servo.angle = positions[position_index]
        
        # Visual feedback for position
        # Map position to a color gradient from green to red
        green = int(255 - (positions[position_index] / 180) * 255)
        red = int((positions[position_index] / 180) * 255)
        pixel.fill((red, green, 0))
        
        # Wait until button is released
        while button.value == False:
            pass
            
        # Short delay after button release
        time.sleep(0.1)

Assessment Criteria

Students will evaluate their prototypes based on how well they address Nathan's needs for precision adjustment of science lab equipment. The evaluation should consider:

1. Functionality: Does the device perform the intended adjustments reliably?
2. Usability: Is the device easy for Nathan to use considering his limited wrist mobility?
3. Adaptability: Can the device be used with different types of lab equipment?
4. Durability: Will the device withstand repeated use in a lab environment?
5. Aesthetics: Is the design visually appealing and appropriate for a school setting?

Activity: "User Testing and Reflection"

1. Simulated User Testing:
   • Have students simulate Nathan's condition by restricting their wrist mobility
   • Test the prototype on various lab equipment adjustments
   • Document observations, successes, and challenges
2. Peer Evaluation:
   • Have student teams evaluate each other's prototypes using the assessment criteria
   • Provide constructive feedback on strengths and areas for improvement
   • Suggest potential modifications or enhancements
3. Reflection and Documentation:
   • Guide students in documenting their design process from start to finish
   • Have students create a short presentation explaining their solution
   • Encourage reflection on what they learned and how they might improve their design

Assessment Rubric

Connections