Your smartphone can measure sound level thanks to its built-in microphone. The FizziQ app (free on iOS and Android) turns your phone into a sound level meter.

1. Open FizziQ on your smartphone or tablet
2. Tap the Measurements tab at the bottom of the screen
3. Tap Instruments (the + icon)
4. In the Sound category, select Sound level
5. The level is displayed in decibels (dB) in real time
6. Tap REC to record how the sound changes over time

Ideal for studying noise pollution, comparing sound sources, or measuring acoustic insulation.

→ See the full instruments guide

FizziQ analyzes the sound picked up by your smartphone's microphone to determine its frequency.

1. In FizziQ, go to Instruments → the Sound category
2. Choose Fundamental frequency to get the main note in Hz
3. Or choose Spectrogram to visualize all the frequencies present

The fundamental frequency is ideal for tuning an instrument or identifying a note. The spectrogram lets you analyze the harmonics and the richness of a sound.

→ See the full instruments guide

FizziQ offers a sound stopwatch that starts and stops automatically by detecting a sound.

1. In FizziQ, go to Tools → Stopwatches
2. Select Sound stopwatch
3. Set the trigger threshold in dB (e.g., 60 dB)
4. The stopwatch starts at the first sound above the threshold and stops at the second

Perfect for measuring the speed of sound (using an echo) or timing events triggered by sound.

→ See the tools guide

FizziQ includes a sound synthesizer that generates precise frequencies through the smartphone's speaker.

1. In FizziQ, go to Tools → Synthesizer
2. Set the frequency (from 20 Hz to 20,000 Hz)
3. Choose the waveform: sine, square, or triangle
4. Adjust the volume and tap Play

Ideal for studying beats between two close frequencies, acoustic resonances, or testing the limits of hearing.

→ See the tools guide

FizziQ lets you measure the speed of sound in several ways thanks to the sound stopwatch.

Method 1: Using an echo

1. Stand facing a wall at a known distance (e.g., 50 m)
2. In FizziQ, go to Tools → Sound stopwatch
3. Clap your hands: the stopwatch measures the round-trip time of the echo
4. Speed = 2 × distance / time (expected result: ~340 m/s)

Method 2: Using two smartphones

1. Place two FizziQ smartphones at a known distance (e.g., 100 m)
2. Start both sound stopwatches
3. A clap triggers both with a slight offset
4. Speed = distance / time offset

→ See the tools guide

Every modern smartphone contains an accelerometer. FizziQ gives you access to this sensor for your experiments.

1. Open FizziQ on your smartphone
2. Go to Instruments → the Motion category
3. Choose Acceleration X, Y, Z, or Absolute
4. The acceleration is displayed in m/s² (or in g)
5. Tap REC to record

Applications: free fall (0g during the fall), circular motion (centripetal acceleration), vibrations, vehicle acceleration.

→ See the full instruments guide

FizziQ uses the smartphone's accelerometer to record the oscillations of a pendulum.

1. Firmly attach the smartphone to the pendulum (with tape, for example)
2. In FizziQ, select Acceleration (the appropriate axis or absolute)
3. Tap REC and let the pendulum swing
4. Stop the recording after several oscillations
5. In the notebook, analyze the graph to measure the period between two maxima

You can also use the sound stopwatch if the pendulum makes a regular click on each pass.

→ See the data analysis guide

FizziQ accesses your smartphone's GPS to measure position, altitude, speed, and distance.

1. Turn on location in your phone's settings
2. In FizziQ, go to Instruments → the Location category
3. Choose: Latitude, Longitude, Altitude, GPS speed, or Distance traveled
4. Tap REC to record your route

Ideal for outdoor experiments: studying the motion of a bicycle, hiking with elevation-gain measurement, mapping.

→ See the full instruments guide

Your smartphone has a light sensor (used to adjust screen brightness). FizziQ uses it as a light meter.

1. In FizziQ, go to Instruments → the Light category
2. Select Brightness (or Illuminance)
3. The level is displayed in lux
4. Tap REC to record the variations

Applications: comparing light sources, verifying the 1/d² law, measuring the lighting of a room, studying attenuation by different materials.

→ See the full instruments guide

A smartphone cannot precisely analyze the color of light. Its light sensor only gives an overall value in lux. To measure the RGB components (Red, Green, Blue), you need the FizziQ Connect box with a color sensor.

What is FizziQ Connect? It is a small electronic box that connects to your smartphone over Bluetooth and lets you plug in specialized sensors.

How to do it:

1. Plug the color sensor (TCS34725) into an I2C port on FizziQ Connect
2. Turn on FizziQ Connect and open the FizziQ app
3. Connect FizziQ Connect over Bluetooth
4. The sensor displays the R, G, B values and the overall brightness

Applications: studying additive color synthesis, analyzing the spectral composition of light sources, doing colorimetry, comparing pigments.

→ See the full FizziQ Connect guide

A smartphone cannot measure temperature: it has no temperature sensor accessible to apps. For this measurement, you need the FizziQ Connect box.

What is FizziQ Connect? It is a small electronic box that connects to your smartphone over Bluetooth. It lets you plug in external sensors (temperature, pH, CO2, etc.) and display their measurements directly in the FizziQ app.

Available temperature sensors:

• Environment sensor (ENV III): ambient temperature + humidity + pressure
• Infrared sensor (MLX90614): contactless temperature (handy for measuring the temperature of an object)
• DS18B20 probe: waterproof probe to submerge in a liquid (-55°C to +125°C)

How to do it:

1. Plug the temperature sensor into FizziQ Connect
2. Turn on FizziQ Connect and open the FizziQ app
3. Tap Instruments then FizziQ Connect to connect over Bluetooth
4. The sensor appears automatically and displays the temperature in °C

→ See the full FizziQ Connect guide

A smartphone cannot measure humidity: it has no hygrometer. For this measurement, you need the FizziQ Connect box with an environment sensor.

What is FizziQ Connect? It is a small electronic box that connects to your smartphone over Bluetooth and lets you plug in external sensors.

How to do it:

1. Plug the Environment sensor (ENV III) into an I2C port on FizziQ Connect
2. Turn on FizziQ Connect and open the FizziQ app
3. Connect FizziQ Connect over Bluetooth (Instruments menu)
4. The relative humidity is displayed as a percentage (%)

Bonus: this sensor also measures temperature and atmospheric pressure in a single step.

Applications: studying the weather, the thermal comfort of a room, food storage conditions, or plant transpiration.

→ See the full FizziQ Connect guide

Some smartphones (especially high-end models) include a barometer. FizziQ accesses it automatically if it is present.

1. In FizziQ, go to Instruments → the Environment category
2. Select Atmospheric pressure
3. The pressure is displayed in hectopascals (hPa)

If your smartphone has no barometer, use FizziQ Connect with the Environment sensor or a dedicated pressure sensor (BMP280).

Applications: tracking weather variations, measuring relative altitude (pressure drops by about 12 hPa per 100 m).

→ See the full instruments guide

A smartphone cannot measure CO2: no smartphone includes a gas sensor. For this measurement, you need the FizziQ Connect box with a CO2 sensor.

What is FizziQ Connect? It is a small electronic box that connects to your smartphone over Bluetooth and lets you plug in external sensors such as a CO2 sensor.

Compatible CO2 sensors:

• SGP30: measures the CO2 equivalent (e-CO2), affordable but less accurate
• SCD40: real CO2 sensor (direct measurement), more accurate for scientific experiments

How to do it:

1. Plug the CO2 sensor into an I2C port on FizziQ Connect
2. Turn on FizziQ Connect and open the FizziQ app
3. Connect FizziQ Connect over Bluetooth (Instruments menu)
4. Wait 2-3 minutes for warm-up to get reliable measurements
5. The CO2 is displayed in ppm (parts per million)

Applications: studying the air quality of a classroom, measuring the CO2 produced by breathing, observing a plant's photosynthesis (CO2 decreases in the light), or tracking fermentation.

→ See the full FizziQ Connect guide

A smartphone cannot measure pH: this chemical measurement requires a specific probe. To measure pH with FizziQ, you need the FizziQ Connect box with a pH probe.

What is FizziQ Connect? It is a small electronic box that connects to your smartphone over Bluetooth. It has an analog port you can plug a pH probe into.

How to do it:

1. Get a compatible pH probe (analog output 0-3.3V)
2. Plug the probe into the analog port on FizziQ Connect
3. Turn on FizziQ Connect and connect it to the FizziQ app over Bluetooth
4. Calibrate the probe with buffer solutions (pH 4 and pH 7)
5. Submerge the probe in your solution and read the pH directly in FizziQ

Usage tips: rinse the probe with distilled water between each measurement and store it in its storage solution (never dry).

Applications: monitoring an acid-base titration, measuring the acidity of a solution, studying chemical reactions.

→ See the full FizziQ Connect guide

Your smartphone contains a magnetometer (used for the compass). FizziQ lets you measure the magnetic field in microteslas (µT).

1. In FizziQ, go to Instruments → the Magnetism category
2. Select Magnetic field (X, Y, Z, or total)
3. The intensity is displayed in µT
4. Tap REC to record the variations

Applications: mapping the field of a magnet, studying electromagnets, measuring the Earth's magnetic field (about 50 µT), detecting metal objects.

→ See the full instruments guide

A smartphone cannot directly measure a distance accurately (except by GPS outdoors, but with an accuracy of only a few meters). For precise measurements, you need the FizziQ Connect box with a distance sensor.

What is FizziQ Connect? It is a small electronic box that connects to your smartphone over Bluetooth and lets you plug in precision sensors.

The ToF (Time of Flight) sensor measures up to 2 meters with millimeter accuracy by sending out an infrared beam.

How to do it:

1. Plug the ToF sensor (VL53L0X) into an I2C port on FizziQ Connect
2. Turn on FizziQ Connect and open the FizziQ app
3. Connect FizziQ Connect over Bluetooth
4. The distance is displayed in real time in millimeters

Applications: studying free fall, measuring the period of a pendulum, tracking the motion of a moving object, creating precise kinematics experiments.

→ See the full FizziQ Connect guide