SPARKY v1.2: An Open Academic Robotics Platform

Sparky v1.2

Sparky (Saint Paul Academic Robotics Kit) is a robotics platform and corresponding curriculum framework informed by and designed for robotics education.  

The robot is student-assembled from maker space manufactured parts and widely available commercial off-the-shelf parts using minimal tools.

The configuration shown is based on the Adafruit Feather microcontroller, but the platform is designed to be microcontroller agnostic. Raspberry Pi Pico W and Arduino reference configurations are also possible.

SPARKY Features:

• Handle for easy, frequent transfer from desktop to testing environment
• Latching hinged lid for easy access to electronics and wiring
• Easily identifiable and accessible power buttons
• Easy to assemble: Only M3 screws are used as fasteners. Assembly is done using only a hex driver and a nut driver 
• Modular and Reconfigurable:  attach different combinations of attachments (sensors & effectors) in different positions and configurations
• Extendable: easy to add new accessories, actuators, and sensors with the standardized M3 mounting hole pattern.
• Sensors, actuators and effectors:
  • Ultrasonic rangefinder
  • IR reflective sensors (x4) for line following
  • Color sensor
  • Micro Servo
  • TT Geared DC Motors (x2) with wheels
  • Axle encoders (x2)
  • Neopixel strip

Design Considerations:

• Make robotics education more accessible to all with a low-cost, widely available, flexible platform. 
• Makerspace manufacturable parts (3D printed PLA and laser-cut) from inexpensive materials. Files for fabrication are freely available online.
• Modular, reconfigurable and extendable: Sensors and actuators and other components can be added, repositioned, removed or replaced without affecting the rest of the robot.
• Vendor agnostic: widely available commercially sourced parts are used to avoid vendor lock-in.
• Microcontroller agnostic: Current design is Adafruit Feather-based. Raspberry Pi Pico and Arduino reference designs are possible with minimal changes to the robot.
• Eco-sustainability considerations: Minimize plastic,  print with bioplastic, use of renewable resources (plywood or eucalyptus hardboard)

3D Printing:

The base model includes the following models to be 3D printed.  All models are printed in PLA with the exception of the caster bearing mounts, which are printed in PETG.

• TT motor mounts (2 mounts - mirrors of each other for L & R sides)
• Wheels 61mm (2x)
• Caster bearing mounts (2x)  [PETG]
• Battery mount
• Breadboard mounts (2 pieces)
• Lid hinges (2x)
• Lid legs (2x)
• Lid latch shoes (2x)
• Handle
• Neopixel nimbus
• IR reflective sensor mounts (4x)
• Color sensor mount
• Ultrasonic sensor mount
• Micro servo mount - horizontal axle
• Wire guides (2x)

Slicer Settings:

Models, unless otherwise specified, were printed on a Bambu X1C in PLA at 0.2mm layer height, the “strength” setting, and no supports. The caster bearing mounts were printed in PETG at 0.2mm layer height with no supports.

Laser Cutting:

The following parts were cut from 3mm Baltic Birch B/BB plywood on a Glowforge Pro using the “Medium Basswood Plywood” setting.   Base and lid are 196mm x 196mm

• OctoBase 
• OctoLid
• Power Panel Labeled
• Button wrench

Additional Materials:

• Adafruit Feather nRF52840
• Adafruit FeatherWing Motor Driver
• Adafruit 5V MiniBoost
• TT geared DC motors 3-6v (2x )
• 2x 1/2" Nylon Ball Precision Bearings
• Breadboard - half-size
• Breadboard jumper wires
• Cylindrical 3.7v LiPo battery
• JST-PH2.0 Battery Extension Cable
• 2x 12mm Mini Latching Push Buttons pre-soldered to jumper wires
• Photo interrupter sensors (2x )
• Neopixel strip (~243mm) pre-soldered to jumper wires
• IR Reflective Sensor Board (4x)
• Ultrasonic sensor
• M3 hex cap screws & nuts - assorted lengths

Assembly:

• Required tools: 2.5mm hex driver and 5.5mm nut driver.
• Assemble the robot as shown using M3 screws and nuts. 
• See Instructable for detailed assembly instructions.