Physical Hardware Verification — Raspberry Pi Pico 2 W

StabilityGuard was integrated and bench-tested on a Raspberry Pi Pico 2 W (RP2350). The pre-existing Wokwi simulation uses a Pico W (RP2040); both variants are retained as separate builds.

Hardware configuration

Device	Connection	Details
Raspberry Pi Pico 2 W	Main MCU	Physical hardware
MPU6050-labeled GY-521 motion module	I²C GP4 (SDA), GP5 (SCL)	Bus address `0x68`; observed `WHO_AM_I = 0x72`
SSD1306 OLED	I²C GP4 / GP5	Bus address `0x3C`, 128×32 physical display
Green / yellow / red LEDs	GP12 / GP11 / GP10	Each uses its own 330 Ω current-limiting resistor
Low-current passive piezo buzzer	GP13	Audible alerts
Momentary fault-injection button	GP14 to GND	Active-low with internal pull-up

What was verified on the physical bench

The builder reports successful checks of:

Pico 2 W USB upload and execution.
MPU sensor response on I²C address 0x68, and live acceleration/tilt readings.
OLED response at I²C address 0x3C, real-time angle display, and state display.
SAFE / WARNING / DANGER transitions with matching green / yellow / red LEDs.
Buzzer alarm output.
Button-triggered SENSOR_FAULT and recovery after release.
Full assembly functioning together using the hardware-specific firmware.

These observations are physical bench checks; they are not a calibrated metrology study, environmental qualification, or a claim of deployment-ready industrial protection.

Sensor-ID compatibility finding

The module on this build communicates at I²C address 0x68 but returned a WHO_AM_I register value of 0x72, rather than the 0x68 commonly reported by genuine MPU6050 devices. This is why an earlier hardware-integration candidate rejected initialization with READ_FAILURE despite the I²C device responding. The physical hardware sketch provisionally accepts the stable, nonstandard ID; it logs a warning and retains the existing acceleration plausibility checks. The exact chip identity has not been established.

Firmware separation

Simulation: src/ remains the tested Pico W Wokwi source and 128×64 OLED configuration.
Physical build: hardware/pico2w/StabilityGuard_Hardware_Pico2W/ contains the physical Pico 2 W Arduino sketch and matching StabilityGuard.h. The core header is byte-identical to the simulation header supplied for this update.
Physical display: SSD1306 128×32 layout.
Physical device startup includes an MPU reset/wake sequence and additional device-ID compatibility logic.

Reproduce the physical setup

Install Arduino IDE 2, Earle Philhower's Raspberry Pi Pico/RP2040/RP2350 board support, and the Adafruit SSD1306/GFX libraries.
Select Raspberry Pi Pico 2 W, and the appropriate USB port.
With USB disconnected, verify all wiring follows the table above, including 3.3 V power, common ground, LED resistors and correct switch polarity.
Open hardware/pico2w/StabilityGuard_Hardware_Pico2W/StabilityGuard_Hardware_Pico2W.ino in Arduino IDE; upload and open Serial Monitor at 115200 baud.
Confirm boot self-test, sensor initialization and live telemetry; verify SAFE, WARNING, DANGER, injected fault and recovery, and the sound/LED outputs.