Lightbox ("One Shot Blinking Light")

Arduino-based firmware developed in the PlatformIO development environment for the Arduino Nano Every.

Functional Specifications

Electronics / PCB

• Powered by 9 V battery, connected with a wire harness (i.e., not mounted directly to the PCB).
• SPST toggle power switch (ON/OFF).
• Arduino Nano Every should be mounted to the board using a socket.
• Single-sided traces.
• Battery, switches potentiometers and LEDs should all be panel-mounted and connected to the board individually using 1x2 sockets.

Commonly Missed Items Checklist

Below is a checklist of things students typically overlook on first pass / should include in their schematics:

• Make sure that off-board components are Excluded from board (in Properties).
• Every connector should have a "mate"; one is on-board, one is off-board.
• Please include your name so we can identify boards during panel milling.
• Don't forget mounting holes!
• Don't forget your schematic (and PCB) metadata!
• Make sure your ERC and DRC pass before submitting for review / milling.

Component Footprints

When choosing a footprint for components, such as resistors, make sure to choose one that will physically allow the component to sit flust on the PCB. For example, a low-wattage, ceramic THT resistor, needs ~10 mm of space (pitch) between its leads to sit flush on a PCB:

Below is a table of the parts you will use in your circuit:

Description	Part Number	Digikey Part Number
Arduino Nano Every	ABX00033	1050-ABX00033-ND
Push Button	PS1024ALRED	EG2025-ND
Toggle Switch	SW-T3-1A-A-A3-S1	2057-SW-T3-1A-A-A3-S1-ND
LED	PM5RD	492-1659-ND
15 Pin Header	PPTC151LFBN-RC	S7013-ND
9V Battery	ZEUS 9V	2059-ZEUS9V-ND
Battery Connector	232	36-232-ND
2 Pin Connector	B02B-XASK-1	455-B02B-XASK-1-ND
2 Pin Jumper	A02XAF02XAF22K152B	455-3061-ND
10k Potentiometer	PDB181-E420K-103B	PDB181-E420K-103B-ND

Firmware

The firmware in this repository is an example of how to approach the function above, but is not the solution for the specifications below!!

• SPST push button switch (ON/OFF) to turn "eye" LEDs on for 5 seconds and "nose" LED for 10 seconds.
• Potentiometer to adjust brightness of "eye" LEDs using Pulse Width Modulation (PWM) (0-100%).
• Potentiometer to adjust blinking rate of "nose" LED (5-10 Hz).
• Have the on-board Nano Every LED (D13) act as a "heartbeat" LED blinking at 1 Hz in all states.

Enclosure

• Make an enclosure of a Blue Devil (or some other fun figure) where two LEDs are the eyes and a third LED is the nose.
• The enclosure will be 3D printed.
• No linear dimension should exceed 15 cm.
• The enclosure should securely hold the PCB and battery internally.
• The power switch and push button should be securely panel mounted.
• The potentiometers should be securely panel mounted in the Blue Devil "ears".
• Any solder junctions between wires should be covered with heat shrink tubing.
• Use snap fit or threaded inserts to attach parts together.
• You do not need to include mechanical drawings in your final submission.
• Include a directory in your git repository called cad/ that includes:
  • A screenshot of your 3D model, saved as model.png.
  • The model.stl file for your 3D model that was 3D printed.

Example "Fun" Enclosures

Project Management / Implementation Expectations

• Fork this git repository and add Dr. Palmeri and your TAs added as Maintainers.
• Questions about debugging code should be submitted as GitLab Issues that are assigned to your TAs (they can escalated to me).
• Include your KiCad project in a subdirectory called circuit/.
• Include your CAD model in a subdirectory called cad/, including the files described above.
• Final firmware should use "best" coding practices discussed in lecture, including:
  • Good firmware architecture:
    • #include
    • #define (MACROS for all pin mappings, specification values, etc.)
    • Function declarations
    • Global variable definitions
    • State machine framework
    • setup()
    • loop() using state machine framework
    • Function definitions
  • Interrupts for all "events"

Circuit

• Please include your entire KiCad project in a directory called circuit/ within your git repository.
• The example circuit below is not valid for the functions above, but just show a representation of some of the desired functionality. ⚠️ This circuit lacks any of the required socket connections.*
• You should overwrite the entire KiCad project with your own design.

Arduino Nano Every Pinout

Testing

Populate the testing/technical_report.ipynb Jupyter notebook in your repository that includes the following:

• Quantify the linear trend (think linear regression) between your potentiometer setting and the brightness of your "eye" LEDs.
• Quantify the linear trend between your potentiometer setting and the blinking rate of the "nose" LED.
• Quantify the accuracy (think 95% CI) of your heartbeat LED blinking at 1 Hz.
• Include a break outline in your report that describes your testing methodology.
• Include all "raw" data measured during testing in data*.csv files.
• Include all statistical analysis and plots associated with your data analysis.
• Discuss any disagreements between your testing results and the expected results from the specifications.

What to Submit

• Create a Merge Request assigned to Dr. Palmeri to submit your final project.
• Make sure that your git repository containts the firmware, CAD and KiCad components described above.
• Schedule a "live" demo of your device for Dr. Palmeri before finals week.
• ⚠️ NO LATE SUBMISSIONS ARE ACCEPTED FOR THIS PROJECT.

Grading Criteria

• Enclosure (25%)
  • Complexity
  • Internal mounting of PCB and battery
  • Secure panel mounting of switches and potentiometers
  • Fit of pieces
  • Meets size constraints
  • git repository organization
• Circuit (25%)
  • Correctness of circuit
  • Correctness of PCB layout
  • Soldering / wire routing / heat shrink tubing
  • Mounting
  • git repository organization
• Firmware (25%)
  • State maching implementation
  • Use of macros, variables, strcuts, etc.
  • Interrupts
  • Modularity of code (e.g., functions)
  • Readability of code
  • git repository organization
• Testing (25%)
  • Technical report
  • Data analysis
  • Live demo
  • git repository organization

Letter Grade Equivalents

• A[+/-]: Industry internship worthy
• B[+/-]: Good, but needs some work
• C[+/-]: Passable, but needs significant work
• D: Major flaws

Resources

• https://docs.platformio.org/en/stable/boards/atmelmegaavr/nano_every.html
• https://docs.arduino.cc/resources/datasheets/ABX00028-datasheet.pdf
• https://hackaday.com/2019/02/28/threading-3d-printed-parts-how-to-use-heat-set-inserts/
• https://docs.arduino.cc/learn/microcontrollers/analog-output/