• Detect tank level at 20%, 40%, 60%, 80%, and 100% points.
• Start the motor automatically when the tank level is low.
• Stop the motor automatically when the tank is full.
• Detect source-water dry-run conditions and stop the motor.
• Detect AC under-voltage and over-voltage and prevent unsafe motor operation.
• Measure motor current for overload, dry-run signature detection, and energy monitoring.
• Provide Auto, Manual, Emergency Fill, Reset, and Bypass controls.
• Show local status using LEDs, buzzer, and a 4.2 inch TFT touch display.
• Send status, alarms, and history through Wi-Fi using MQTT or an app backend.
• Support OTA firmware updates.

• ESP32-based Wi-Fi and Bluetooth controller.
• Dual-PCB safety architecture.
• Five tank-level inputs plus dry-run source-water input.
• Image-reference layout variants include a premium touch/network edition, a smart lever/level controller layout, and an IoT PCB marking layout.
• Voltage monitoring using an isolated AC voltage sensor module or equivalent circuit.
• Current monitoring using ACS712, SCT013, or a production-grade isolated current sensor.
• Relay or contactor driver output for pump control.
• Dedicated motor relay or contactor output area, with heavy-duty relay/contactors kept physically separated from ESP32 logic.
• Surge and lightning protection using fuse, MOV, GDT, EMI filtering, and NTC inrush limiting.
• Clearly labeled AC input, motor output, tank sensor, dry-run sensor, voltage sensor, current sensor, relay power, and TFT connectors.
• RTC for scheduling and event timestamps.
• Non-volatile memory for settings and calibration.
• Touch display option for premium model.
• Front-panel status LEDs for power, motor, dry-run, voltage fault, tank level, and general fault status.

Diagram

• 230 VAC input connector with fuse.
• MOV and GDT surge protection.
• EMI filtering and NTC inrush limiter.
• Isolated AC-DC SMPS for low-voltage power.
• Voltage sensing with isolation.
• Current sensing with safe isolation.
• Relay or contactor output for motor control.
• Isolation boundary to the logic board.

• ESP32 module, preferably a certified module with integrated antenna.
• 3.3 V regulator and local decoupling.
• Tank level and dry-run sensor input protection.
• TFT touch display interface.
• LEDs, buzzer, and buttons.
• RTC such as DS3231.
• Non-volatile memory if required beyond ESP32 flash/NVS.
• Programming and debug access.

• AC mains input: phase, neutral, earth where available.
• Pump output: phase and neutral through relay or contactor wiring.
• Inter-board power: isolated low-voltage DC from Board A to Board B.
• Inter-board signals: isolated voltage sense, current sense, relay command, and fault/status lines as needed.
• Tank probes or sensor connector: S1 to S5 plus common/reference.
• Dry-run input connector.
• TFT connector.
• Buttons: Auto/Manual, Emergency Fill, Reset, Bypass.
• Five-key manual backup concept from the reference images: Left, Right, Up, Down, OK, and Undo for menu navigation when a touch display is not used.
• Dedicated front-panel LED connector for power, motor, fault, and tank-level indication.
• Buzzer and fault/status LEDs.
• Wi-Fi antenna zone: ESP32 antenna must face a board edge with no copper keepout.

Diagram

• Dual-PCB architecture is preferred for safety, serviceability, and noise reduction.
• High-voltage PCB must maintain mains creepage and clearance distances and include isolation slots where appropriate.
• Low-voltage PCB can use compact SMD assembly, but connectors and controls should be field-serviceable.
• Add test points for 5 V, 3.3 V, GND, relay command, voltage sense, current sense, and key sensor inputs.
• Use certified AC-DC power module where possible to reduce mains safety risk.

• Stable ESP32 boot circuit with EN pull-up, reset button, GPIO0 boot button, and programming access.
• MQTT support for Home Assistant, Node-RED, Blynk, ThingsBoard, or a custom app.
• OTA firmware update support.
• NVS or external EEPROM for calibration, thresholds, Wi-Fi credentials, and fault history.
• RTC for pump schedules, runtime logging, and timestamped alarms.
• Fault state machine for dry-run, over-voltage, under-voltage, overload, bypass, and manual mode.

• Two physically separated boards or one enclosure with separated compartments.
• High-voltage terminals must be shielded and clearly labeled.
• Low-voltage UI board should place TFT, buttons, and LEDs on the enclosure front panel.
• ESP32 antenna must be kept away from metal enclosure walls, large copper pours, and high-current switching areas.
• Reference-image PCB marking style should be preserved in the production design: large connector labels, bilingual/local-language user-facing labels where needed, and clear service markings for AC input, motor output, sensors, relays, and USB/programming access.
• Keep the high-voltage protection and relay zones near the AC/motor terminals, and keep ESP32, display, buttons, and sensor connectors in the low-voltage service area.

• Use dual-PCB architecture for the premium industrial product.
• Use ESP32 module instead of bare ESP32 chip to simplify RF design and improve Wi-Fi reliability.
• Use isolation between mains sensing/control and ESP32 logic.
• Use a contactor or industrial relay for high-current motor loads rather than routing motor current through the logic PCB.
• Treat the 4.2 inch TFT touch display as the premium UI option.
• Preserve the reference concepts as visual targets, but treat them as product-layout inspiration rather than safety-verified electrical schematics.

• Nominal mains supply is 230 VAC.
• Initial voltage protection thresholds are 170 VAC under-voltage and 260 VAC over-voltage.
• Motor load may be up to 30 A, so final switching should use an external contactor or appropriately certified relay assembly.
• Exact tank sensors, TFT module, contactor coil voltage, enclosure, and compliance target are not yet selected.
• This first revision captures architecture and requirements before detailed schematic component selection.

• Created initial specification from the user's Smart IoT Water Level Controller concept.
• Captured the recommendation to combine dual-PCB industrial architecture, ESP32 plus MQTT, 4.2 inch TFT, RTC, EEPROM/settings storage, surge protection, dry-run protection, and mobile alerts.
• Updated from uploaded reference images: added labeled connector expectations, front-panel LED connector, five-key backup UI, touch/network edition marking, relay/protection zone separation, and PCB service-labeling requirements.