IoT Touchless Tap Controller with Hand Detection

Public and shared taps are touched by hundreds of hands a day, and every touch is a hygiene risk — one more reason touchless fixtures have moved from airports into schools, hostels and hospitals. Commercial sensor taps are expensive and need a plumber; this project builds the same idea as a student retrofit: an infrared hand-detection sensor, an ESP32 controller and a 12 V solenoid valve that opens the water only while hands are present. Because every activation is timed and counted, the controller also reports usage to a Wi-Fi dashboard, turning the build into a water-saving demonstration: water flows only on demand, never left running. It is an honest prototype — a bench-demonstrated retrofit with estimated (not metered) water volumes.

1. The IR proximity sensor continuously watches the hand zone under the tap outlet.
2. When hands enter the zone, the sensor output goes active and the ESP32 wakes the valve driver.
3. The relay/MOSFET stage energizes the 12 V solenoid valve, which opens and water flows.
4. The ESP32 times the activation; when hands leave the zone, the valve closes immediately.
5. If flow reaches the configured safety timeout, the valve closes regardless of the sensor state until the zone clears.
6. Each activation's duration is logged and sent over Wi-Fi to the dashboard, which shows counts, total open time and the estimated water volume.

Tech stack:

• ESP32 development module (detection logic, Wi-Fi telemetry)
• IR proximity/obstacle sensor for hand detection
• 12 V DC normally-closed solenoid valve
• Relay/MOSFET driver stage for the valve
• Blynk or local web dashboard (usage counts, water-use estimate)
• 12 V adapter or battery pack power options
• Retrofit plumbing adapters for standard tap inlets
• Splash-resistant prototype housing

• IR hand detection: An infrared proximity sensor watches the basin zone; detection range and sensitivity are adjustable in firmware for different mounting positions.
• Solenoid valve control: A normally-closed 12 V DC solenoid valve opens the water line only while hands are detected, driven through a relay/MOSFET stage.
• Adjustable flow timing: Maximum continuous flow time and re-trigger behaviour are configurable, so the tap suits handwash, fill and rinse use cases.
• Safety shutoff timeout: A hard timeout stops the flow even if the sensor stays triggered, preventing flooding from a stuck sensor or an object left in the basin.
• Usage counting and dashboard: Every activation is counted and valve-open time is reported over Wi-Fi to a dashboard with daily totals and a water-use estimate.
• Retrofit installation: The valve assembly fits a standard tap inlet with documented adapters — the existing tap body is not modified.
• Low-voltage safe design: Only 12 V DC reaches the wet area; mains stays in the adapter, and the control electronics sit in a splash-resistant housing.
• Battery/mains options: Runs from a 12 V adapter for fixed installation or a battery pack for portable demonstration.

• Assembled touchless tap controller (sensor, ESP32, valve driver, housing)
• 12 V solenoid valve with retrofit plumbing adapters
• Tap mock-up/demo rig for bench demonstration
• ESP32 firmware source code (detection, timing, safety timeout, Wi-Fi telemetry)
• Wiring diagram and plumbing connection drawing
• Component list with valve and sensor details
• Project report PDF (background, sensor and valve theory, design, test procedure, water-saving estimate)
• PPT presentation for final review
• Viva Q&A preparation document (IR sensing, solenoid valves, ESP32, water estimation, hygiene design)
• Installation and calibration guide

• Water volume is estimated from valve-open time at a nominal flow rate, not measured by a flow meter — the dashboard figure is an estimate and is labeled as such.
• Detection range and reliability depend on mounting position, ambient light and the basin material; calibration per installation is needed and documented.
• The solenoid valve needs reasonably clean water; sediment can prevent full closure, so an inlet filter is recommended and documented.
• This is an academic prototype, not a certified plumbing product: it is for demonstration and has not undergone pressure or potable-water certifications.
• The retrofit suits the documented standard inlet sizes; unusual tap threads need custom adapters (available as customization).
• Wi-Fi telemetry is a bonus layer — hand detection and valve control run fully locally on the ESP32 with no network needed.