Team MasterDoom · University of Pennsylvania ESE 5160

Custom Embedded PCB & Firmware

An embedded systems project centered on a custom SiWG917 PCB and the firmware/system integration around it. The repository documents Altium schematic/layout work, board fabrication and assembly, bench bring-up, power validation, MQTT communication, LCD/joystick UI, camera capture, and a FastAPI/YOLOv3 inference tradeoff.

Altium DesignerSiWG917PCB DesignJLCPCBHardware Bring-UpMQTT

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Overview

Project Strengths

Custom SiWG917 PCB spanning hierarchical schematics, PCB layout/routing, component placement, power architecture, USB/protection, battery charging, regulated 3.3 V and 5 V rails, and peripheral interfaces.
Manufacturing preparation followed by board fabrication, assembly, optical inspection, manual soldering/rework, and electrical validation.
Bring-up workflow centered on subsystem checks, test points/jumpers, power-mode validation, oscilloscope captures, electronic-load testing, thermal imaging, and programming/debug attempts.
Firmware and system integration across MQTT messaging, ST7735R LCD UI, joystick input, camera capture/upload, Node-RED dashboard flow, and OTA-oriented command handling.

My Contribution

Designed and brought up the custom SiWG917 PCB through schematic capture, layout, 3D verification, power-path validation, thermal checks, and rework.
Integrated and debugged firmware paths across MQTT/networking, LCD UI, joystick input, camera upload, and game-state behavior.
Validated board power behavior and documented the engineering tradeoffs behind reference-hardware firmware execution.
Team MasterDoom included Yunzhe Deng and Jilu Wang; the site presents the work as a team ESE 5160 project.

System / Architecture

Architecture

01Problem / goal: build a connected embedded poker assistant while designing a custom SiWG917 PCB rather than treating the project as only development-board firmware.
02PCB design: integrate MCU, 3.3 V and 5 V power, battery charging, USB/protection, SD card support, LCD/camera interfaces, motor/encoder-related interfaces, test points, and jumpers.
03Manufacturing and assembly: prepare manufacturing outputs, fabricate and assemble the board, inspect it, and rework population/orientation issues recorded in bring-up notes.
04Hardware bring-up: validate power paths and subsystems with oscilloscope captures, electronic loads, thermal imaging, peripheral checks, and programming/debugging attempts.
05System integration: continue final firmware execution on reference SiWG917 development hardware after custom-board flashing remained unreliable, while retaining the custom PCB as a validated hardware artifact.

Implementation

Created Altium Designer schematic/layout/manufacturing artifacts for the custom SiWG917 board and reviewed the design through PCB layout and 3D render evidence.
Validated 3.3 V and 5 V rails under 50 mA through 600 mA electronic-load tests, oscilloscope startup/steady-state captures, and thermal imaging.
Retained main-controller firmware modules for board/BSP mapping, GPIO/I2C/SPI wrappers, ST7735R display rendering, joystick ADC/switch input, MQTT, vision bridge, simulation, and strategy logic.
Retained camera-node firmware for OV2640 register/SPI/I2C control, image capture, HTTP upload, retry handling, and local JPEG inspection.
Moved card recognition off-device after SiWG917 memory constraints made useful on-device YOLO detection impractical; FastAPI/YOLOv3 results return through MQTT.

Angled 3D render of the custom SiWG917 PCB — 3D PCB render used for design review before fabrication.

Visual Evidence

Hardware and system artifacts

2D PCB layout for the custom embedded board — PCB layout evidence from the custom SiWG917 board design.

Back view of the fabricated custom PCBA — Fabricated PCBA back view after manufacturing and assembly.

Top-level schematic for the custom embedded PCB — Top-level schematic showing board-level hardware integration.

Oscilloscope capture of 5 volt startup transient — Power-rail validation during board bring-up.

System architecture for camera, cloud inference, MQTT, and embedded display — Camera-to-cloud-to-embedded architecture used for final system integration.

Results / Validation

Custom PCB was designed, fabricated, assembled, visually inspected, reworked, and electrically validated.
3.3 V and 5 V power rails were tested with oscilloscope captures and electronic-load testing from 50 mA through 600 mA.
Working prototype architecture demonstrated on reference SiWG917 development hardware with OV2640 capture, MQTT messaging, LCD output, joystick input, Node-RED dashboard interaction, and OTA-oriented firmware logic.
The public repository preserves the custom-board flashing issue explicitly rather than implying that final firmware ran from the custom PCB.

Challenges / Decisions

Custom-board firmware flashing remained unreliable, so final application development continued on reference SiWG917 development hardware.
MCU memory limits pushed the card-detection workload off-device to FastAPI + YOLOv3.
End-to-end integration depended on Wi-Fi, HTTP upload, inference service availability, MQTT broker reliability, and display-state synchronization.
The public firmware snapshot is curated and excludes generated SDK trees, build output, credentials, and third-party font data without clear redistribution permission.