AIRU 03 — ESP32 and Electronics

Embedded-systems vocabulary, interfaces, power, sensing, BLE, BOM review and bench validation for AIRU V1.

ESP32

A low-cost microcontroller with Wi-Fi and Bluetooth Low Energy used in V1 for sensor reading, rule logic, display control, and optional data transmission.

ESP32 development board vs production module

A development board includes USB programming, regulation, and convenient headers. V1 uses a dev board; a production design would need a reviewed PCB and power architecture.

ESP32 logic voltage

ESP32 GPIO uses approximately 3.3 V logic and is generally not 5 V tolerant. Interfaces must be checked before connection.

ILI9341

A common TFT display controller used in 2.4-inch 240×320 modules; V1 typically communicates with it through SPI.

SPI (Serial Peripheral Interface)

A synchronous digital interface using clock, data, chip-select, and often additional display-control pins such as DC and reset.

Why check an ILI9341 module's exact board version?

Modules differ in voltage regulators, level shifting, touch controllers, SD slots, and backlight wiring. The controller name alone does not define safe connections.

GP2Y1010

A Sharp optical dust sensor used for relative dust-response demonstrations. It is obsolete/EOL and should not anchor a production sensor claim.

How does the GP2Y1010 detect dust?

An internal LED illuminates particles and a photodetector produces an analog signal related to scattered light.

Why does GP2Y1010 pulse timing matter?

The emitter LED must be driven and the analog output sampled at the specified timing. Arbitrary continuous readings can be noisy or inaccurate.

GP2Y1010 reference components

The AIRU brief calls for checking the Sharp reference circuit, including a 150-ohm resistor and 220-microfarad capacitor, plus correct LED pulse timing.

Relative detection vs calibrated concentration

V1 needs a repeatable change when dust is introduced. It should not claim accurate particle concentration without calibration and a validated sampling path.

ADC (analog-to-digital converter)

The ESP32 ADC converts an analog sensor voltage into a digital number. Input range, attenuation, noise, and reference behavior must be checked.

What is AIRU's sustained dust rule?

A dust reading must remain above the chosen threshold for more than about three seconds before displaying DUST DETECTED.

Why use a sustained threshold?

It filters brief spikes and makes the demonstration more stable, repeatable, and understandable.

Hysteresis

Using different thresholds for turning an alert on and off to prevent rapid flickering when readings hover near one value.

Breadboard prototype

A solderless, quickly changeable circuit suitable for V1 validation. It is not mechanically robust or electrically ideal for a finished consumer product.

Dupont jumper wires

Temporary plug-in wires used for breadboard connections; they are convenient but can loosen and should be strain-relieved during filming or transport.

Why is a TP4056 not a complete power system?

It is primarily a single-cell Li-ion/LiPo charger. AIRU still needs correct regulation, protection, load sharing, connectors, and current-capability checks.

Nominal voltage of a single-cell LiPo

About 3.7 V nominal and up to approximately 4.2 V when fully charged. It must not be assumed to equal a clean 3.3 V rail.

Why keep the 12 V proxy motor off the ESP32 rail?

The motor draws far more current and creates electrical noise. It requires its own suitable supply and ESC while sharing ground only when the interface requires it.

Common ground

A shared electrical reference between interacting circuits. It is often necessary for control signals, but must be designed deliberately around separate power domains.

Decoupling capacitor

A capacitor placed near a device's supply pins to reduce local voltage dips and high-frequency noise.

Why measure current draw?

It checks whether regulators, wires, batteries, and connectors have adequate capacity and reveals stalls, shorts, or unstable power behavior.

Pin conflict

Two functions accidentally assigned to the same GPIO or to a pin with incompatible boot, ADC, SPI, or input-only behavior.

BLE (Bluetooth Low Energy)

A low-power wireless method that can transmit current dust value, mode, and alert status from the ESP32 to a simple phone interface.

What BLE work is optional in the five-hour review?

A minimal data-output recommendation is optional only after power, wiring, BOM, and bench-validation deliverables are complete.

Why is a production PCB out of scope for V1?

The immediate goal is a reliable breadboard/dev-board demonstration. PCB layout would consume time before interfaces and requirements are stable.

Corrected BOM

A bill of materials listing exact parts or minimum specifications, quantities, acceptable substitutes, reasons, and do-not-buy warnings.

Safe bench-test order

Inspect wiring, current-limit the supply, verify rails without modules, power the ESP32, test the display, test the sensor, integrate the alert rule, then repeat and record failure behavior.

What completes AIRU's embedded review?

A marked-up wiring/power diagram, corrected BOM, numbered pass/fail bench checklist, prioritized buy/change/do-not-buy list, and proof-stage limitations.