Automatic Hand Sensing Water and Soap Tank with Tap
This automatic tank for water and soap prevents the spread of coronaviruses in public places while, at the same time, prohibiting touch-ups of the faucet. In March 2020, the World Health…
Know the mission before touching a wire.
Understand what you are making, prepare the right tools, and make the workbench safe.
Project details
Automatic Hand Sensing Water and Soap Tank with Tap is a arduino project. This automatic tank for water and soap prevents the spread of coronaviruses in public places while, at the same time, prohibiting touch-ups of the faucet. In March 2020, the World Health…
- Source pages
- 659-662
- Named parts
- 8
- Build goal
- Working, tested prototype
Tools you need
- Digital multimeter
- Wire stripper and side cutters
- Soldering iron with a fine tip
- Current-limited bench supply
- Computer with a data-capable USB cable
Use eye protection, good lighting, and a clean insulated surface throughout the build.
Safety precautions
- Disconnect every power source before changing a connection.
- Check component polarity, pinout, and supply voltage twice.
- Use a current limit for the first power-up.
- Keep liquids, loose metal, and uninsulated wires away from the bench.
Gather, identify, and understand every part.
Use the standardized inventory, then open What's this? to learn each part's role, advantages, limitations, handling, and specifications.
What's this?Image, role, pros, cons, handling & specifications
Water reservoir
A named project component whose exact role is defined by the source circuit and build guide.
What it does hereIt performs a documented electrical, control, interface, or construction function in this project.
Buy / compare this part ↗Advantages
- Selected for this project
- Can be checked independently
- Supports modular troubleshooting
Limitations
- Substitutes may differ
- Generic names can hide variants
- Pinouts and ratings vary
Handling
- Compare the received part with the source
- Keep it labelled
- Do not force connectors or adjusters
Specifications to verify
- Use the exact model, value, package, and rating listed for Water reservoir; similar-looking parts are not always interchangeable.
- Confirm dimensions, ratings, connection method, polarity, and environmental limits.
What's this?Image, role, pros, cons, handling & specifications
Soap reservoir
A named project component whose exact role is defined by the source circuit and build guide.
What it does hereIt performs a documented electrical, control, interface, or construction function in this project.
Buy / compare this part ↗Advantages
- Selected for this project
- Can be checked independently
- Supports modular troubleshooting
Limitations
- Substitutes may differ
- Generic names can hide variants
- Pinouts and ratings vary
Handling
- Compare the received part with the source
- Keep it labelled
- Do not force connectors or adjusters
Specifications to verify
- Use the exact model, value, package, and rating listed for Soap reservoir; similar-looking parts are not always interchangeable.
- Confirm dimensions, ratings, connection method, polarity, and environmental limits.
What's this?Image, role, pros, cons, handling & specifications
Two touchless proximity sensors
A named project component whose exact role is defined by the source circuit and build guide.
What it does hereIt performs a documented electrical, control, interface, or construction function in this project.
Buy / compare this part ↗Advantages
- Selected for this project
- Can be checked independently
- Supports modular troubleshooting
Limitations
- Substitutes may differ
- Generic names can hide variants
- Pinouts and ratings vary
Handling
- Compare the received part with the source
- Keep it labelled
- Do not force connectors or adjusters
Specifications to verify
- Use the exact model, value, package, and rating listed for Two touchless proximity sensors; similar-looking parts are not always interchangeable.
- Confirm dimensions, ratings, connection method, polarity, and environmental limits.
What's this?Image, role, pros, cons, handling & specifications
Two low-voltage liquid pumps or solenoid valves
An output component turns an electrical control signal into light, sound, motion, switching, or displayed information.
What it does hereIt presents the circuit result or acts on the physical world.
Buy / compare this part ↗Advantages
- Makes system state visible
- Can be tested separately
- Supports clear troubleshooting
Limitations
- Loads may exceed controller current
- Polarity or driver direction can matter
- Inductive loads create voltage spikes
Handling
- Use the documented driver stage
- Check polarity and load current
- Add flyback protection for inductive loads
Specifications to verify
- Use the exact model, value, package, and rating listed for Two low-voltage liquid pumps or solenoid valves; similar-looking parts are not always interchangeable.
- Confirm voltage, current, polarity, interface, driver requirements, and duty cycle.
What's this?Image, role, pros, cons, handling & specifications
Controller board shown in the wiring diagram
A programmable controller that reads inputs, makes decisions, and drives the project's outputs.
What it does hereIt is the control centre and must use the documented board, pin map, supply, and logic level.
Buy / compare this part ↗Advantages
- Reprogrammable and reusable
- Large learning ecosystem
- Complex behaviour remains changeable
Limitations
- GPIO voltage and current are limited
- Some pins affect boot or communication
- Loads normally need a driver
Handling
- Disconnect power before rewiring
- Avoid static discharge
- Never power motors, relays, or pumps directly from GPIO
Specifications to verify
- Use the exact model, value, package, and rating listed for Controller board shown in the wiring diagram; similar-looking parts are not always interchangeable.
- Confirm operating voltage, logic level, pinout, memory, USB interface, and maximum GPIO current.
What's this?Image, role, pros, cons, handling & specifications
Relay driver module
An output component turns an electrical control signal into light, sound, motion, switching, or displayed information.
What it does hereIt presents the circuit result or acts on the physical world.
Buy / compare this part ↗Advantages
- Makes system state visible
- Can be tested separately
- Supports clear troubleshooting
Limitations
- Loads may exceed controller current
- Polarity or driver direction can matter
- Inductive loads create voltage spikes
Handling
- Use the documented driver stage
- Check polarity and load current
- Add flyback protection for inductive loads
Specifications to verify
- Use the exact model, value, package, and rating listed for Relay driver module; similar-looking parts are not always interchangeable.
- Confirm voltage, current, polarity, interface, driver requirements, and duty cycle.
What's this?Image, role, pros, cons, handling & specifications
Regulated DC power supply
A power component supplies, converts, stores, or regulates energy for the project.
What it does hereIt must provide the documented voltage, polarity, isolation, and sufficient current safely.
Buy / compare this part ↗Advantages
- Stable power improves reliability
- Current limiting protects first tests
- Regulation reduces resets and noise
Limitations
- Wrong polarity can cause immediate damage
- Underrated parts overheat
- Mains circuits require qualified supervision
Handling
- Measure output before connection
- Use a fuse or current limit
- Insulate exposed conductors
Specifications to verify
- Use the exact model, value, package, and rating listed for Regulated DC power supply; similar-looking parts are not always interchangeable.
- Confirm input/output voltage, current, polarity, connector, isolation, and thermal rating.
What's this?Image, role, pros, cons, handling & specifications
Tubing and dispensing nozzles
A named project component whose exact role is defined by the source circuit and build guide.
What it does hereIt performs a documented electrical, control, interface, or construction function in this project.
Buy / compare this part ↗Advantages
- Selected for this project
- Can be checked independently
- Supports modular troubleshooting
Limitations
- Substitutes may differ
- Generic names can hide variants
- Pinouts and ratings vary
Handling
- Compare the received part with the source
- Keep it labelled
- Do not force connectors or adjusters
Specifications to verify
- Use the exact model, value, package, and rating listed for Tubing and dispensing nozzles; similar-looking parts are not always interchangeable.
- Confirm dimensions, ratings, connection method, polarity, and environmental limits.
Connect one verified path at a time.
Explore the named components and standardized signal flow, then use Source Check to verify exact physical pins, values, and topology before applying power.
Trace this circuit.
Automatic Hand Sensing Water and Soap Tank with Tap: interactive parts, standardized terminals, responsive anchored wires, student explanations, and the original circuit reference in one shared system.
Trace before wiring
Follow power, ground, inputs, processing, and outputs in that order. Never guess a pin from package shape alone.
Connect with power off
Make short, labelled connections and share a common ground only where the schematic requires it.
Inspect every joint
Check continuity, polarity, adjacent shorts, and loose connections before the first power-up.
Open all source diagrams and build views 2 visuals
Confirm the hardware-only control path.
This project does not include firmware in the source. The circuit itself provides the required behaviour.
How to connect
- Match every controller label to the circuit view and source pin map.
- Join grounds before signal wires when separate low-voltage supplies are used.
- Keep motors, relays, pumps, and other loads on a suitable driver and external supply.
Common mistakes
Reversed VCC/GND, board-label versus GPIO-number confusion, missing common ground, and charge-only USB cables.
Troubleshoot
Disconnect loads, continuity-test one path at a time, then test with a current limit.
Software preparation
No IDE, board package, library, or firmware upload is required for this project.
If you add a programmable controller as an extension, document its pin map separately.
How to upload code
The original design is implemented entirely in hardware, so proceed after verifying the circuit and supply.
Assemble, deploy, test, and troubleshoot.
Use the complete source notes in build order, then pass the final checks before calling the project finished.
Build in functional stages
- Power and regulation
- Controller or processing stage
- Inputs and sensors
- Outputs and loads
- Enclosure and strain relief
Power up safely
- Inspect unpowered continuity first
- Apply the lowest safe current limit
- Measure supply rails before signals
- Add one load at a time
- Record expected and actual results
Work from simple to complex
- Confirm power, ground, polarity, and orientation
- Compare each pin with the source
- Test inputs separately from outputs
- Replace only one variable at a time
- Power off before every correction
Follow the documented instructions.
These notes come from this project's source and remain in their original order.
Project overview
Project build noteThis automatic tank for water and soap prevents the spread of coronaviruses in public places while, at the same time, prohibiting touch-ups of the faucet.
In March 2020, the World Health Organization (WHO) declared a global pandemic of a novel coronavirus outbreak that caused a respiratory illness that was first discovered in Wuhan, China. The World Health Organization estimates that the number of confirmed HIV cases and deaths is over 3 million by the end of April 2020.
People can contract the disease directly from an infected person or indirectly through touching surfaces contaminated with viral droplets. Since specific treatments for the outbreak or a vaccine are not yet available, it is crucial to prevent the outbreak from spreading from person to person and affecting people's lives, health, livelihoods, and the healthcare systems we are all relying on. Infected people spread the COVID-19 virus mainly by sneezing or coughing droplets of saliva. It is important to properly wash your hands in order to prevent COVID-19.By providing safe water, sanitation and basic hygiene measures during hand washing, as well as prohibiting retouching of the faucet to avoid decontaminating the water source or tap and posing further risks to another user, this can be achieved. People who obtain automatic hand sensing water and soap dispensers will not only be able to wash their hands with ease, but will also be afforded proper hygiene facilities, however limiting the time in which people are in contact with the tap would prevent recontamination. Statement of Problems. In order to prevent the spread of this virus, the government of Nigeria has taken the necessary measures by ensuring a lockdown policy in states with high incidence of the coronavirus. The major contact point for people moving out of and into the city after lockdown when they're using the Motor Parks doesn't have running water. Spreading the virus in this manner would make one more vulnerable to infection by infecting one another. Recent data from UNICEF indicates that worldwide, only three out of five people have basic hand washing facilities.
People should thus be taught to keep proper hygiene, as well as wash their hands often in order to remain safe and alive in these parks. The most important thing is to reduce the spread of this virus and defeat coronavirus.
You built Automatic Hand Sensing Water and Soap Tank with Tap.
You followed the full workflow from understanding the mission to testing the finished project. That is a real engineering achievement - well done.
DIY GPS Speedometer using Arduino and OLED
Ready to reuse what you learned in another project from the same track?
Start this project →