Ultrasonic Parking Guide Kit

Classes 7-8, typical ages 12–14. Age ranges vary by learner. Guided low-voltage electronics.

Activity engagement

60–90 minutes. Explore 10–15 min · Build 20–30 min · Test and discuss 30–45 min. Estimated time for building, testing and discussion.

What you need

A computer with a USB port and Arduino IDE is required and is not included.

Included components

• Small Breadboard / Mini Solderless Board - 400 points — 1 breadboard
• Jumper Wire Combo - Male to Male, Male to Female and Female to Female Breadboard Connecting Wires (10 Qty Each) — 1 set
• Illustrated Activity Guide and Observation Sheets — 1 set
• Fitted Headers and Labelled Connection Leads — 1 set
• Arduino Uno R3 CH340G version compatible Arduino Development Board — 1 controller board
• USB A to B Programming Cable for Arduino Uno/ Arduino Mega — 1 data cable
• HC-SR04 Ultrasonic Distance Sensor Module — 1 sensor module
• Small Piezoelectric Buzzer - 5V Passive Buzzer — 1 piezo sounder

What you learn

• Distance can be estimated from echo round-trip time.
• Missing echoes must be handled as invalid readings.
• Thresholds turn a measured value into a response.

Connection guide

• HC-SR04 VCC → 5 V; GND → GND; TRIG → D7; ECHO → D6.
• Passive piezo + → D9; − → GND.

Steps to make it

1. Disconnect all power and identify the supplied part labels and pinouts before wiring.
2. Wire the sensor and passive piezo, pointing the transducers toward a flat target.
3. Upload and open Serial Monitor; compare a ruler with readings at 10, 20 and 40 cm.
4. Move the target inside 15 cm and listen for the alert.
5. Remove the target and confirm that an invalid/no-echo reading is not treated as zero distance.
6. Change only the named parameter for the extension, repeat the controlled trials, save observations and disconnect power afterward.

Programming resources

Arduino IDE: select Arduino Uno and the USB port. Use the supplied USB data cable. Serial Monitor/Plotter: 115200 baud.

Uses the selected board core libraries.

Download starter sketch

Test challenge

Compare five readings at each known target distance; vary target angle once.

Observation task

Ruler distance, five sensor estimates, mean error and any invalid echoes.

Expected result

The sketch prints a distance estimate and sounds only when a valid target is closer than 15 cm.

If it does not work

Confirm TRIG/ECHO assignments and use a firm flat target. Soft or angled surfaces may not return a usable echo.

Try next

Replace the fixed alarm with three distance bands.

Use and supervision

Use only the supplied low-voltage DC parts. Disconnect power before rewiring; check polarity and labelled pinouts. No soldering or exposed mains connections. Adult guidance is recommended.

How this experiment works

Download class activity guide

Cover illustrations show component types. Functional animations explain principles and are not recorded prototype tests. Follow the supplied connection labels and pinouts.