A physical game controller for a live iOS shooter
Designed and built a production-ready gun-shaped controller for WarStrike — a first-person shooter iOS game. The controller mounts an iPhone on a barrel rail and uses a physical trigger wired to an ESP32 that communicates with the game over Bluetooth Low Energy. Took it from first prototype through firmware, full BOM, assembly documentation, and a China manufacturing pipeline.
Prototypes in Green & Blue
Multiple colorway iterations 3D printed in PLA to validate the enclosure geometry and ergonomics before finalizing for production.
Electronics & Firmware
ESP32-CAM module handles Bluetooth communication. Trigger pull actuates a micro limit switch — debounced in firmware at 10ms for fast, reliable shot detection. Each unit is flashed with a unique Gun ID so multiple controllers pair independently.
ESP32 Flashing Pipeline
Production flashing guide designed so assembly staff can program each unit without engineering involvement — increment Gun ID per unit, compile and flash via Arduino IDE.
Bill of Materials & Parts Design
Full BOM covering all internal electronics and plastic enclosure parts, with supplier links and per-unit cost breakdowns. Plastic parts designed for ABS or PA injection molding — grip halves and barrel halves each consolidate into single parts for tooling efficiency.
Embedded Systems
- Microcontroller: ESP32-CAM — handles BLE server, shot detection, and LED feedback.
- Trigger Input: Micro limit switch with 10ms debounce — fast enough for single-shot detection without false inputs.
- BLE Protocol: Custom service + TX characteristic UUID; each gun advertises a unique GUN_ID for multi-player pairing.
- Power: 2600mAh USB-C rechargeable battery pack in grip, accessed via a sliding latch.
Mechanical Design
- Enclosure: 6-part split-shell — grip (×2), barrel (×2), trigger, battery latch. Grip and barrel halves each consolidate to single parts for injection mold tooling.
- Fastening: 8× heat-set brass threaded inserts with M3 and M2.5 screws — fully serviceable, no adhesive.
- Phone Mount: ¼" screw-thread clamp on barrel rail, compatible with all iPhone sizes.
- Material: PLA for prototyping; ABS or PA for production injection molding.
Supply Chain
- China Manufacturing: Identified and qualified injection molding suppliers for high-volume enclosure production, covering tooling cost, lead times, and per-unit targets.
- Full BOM: All parts — electronics, hardware, and plastic — documented with supplier links, quantities, and cost per unit.
- Assembly Docs: Step-by-step build and flash instructions delivered so production can run without engineering on-site.