Getting Started

Getting Started

1. What you need

• A Chromium-based browser with Web Serial support:

  Browser	Minimum version
  Chrome	89
  Edge	89
  Opera	75
  Brave	1.24

  Firefox and Safari do not support Web Serial.

• A supported sensor — see Supported Sensors.

• A USB-to-UART adapter (CP2102, CH340, FT232, etc.), unless your sensor already has USB. I²C sensors such as the Sensirion SEN63C / SCD41 / SEN66 need an I²C-to-USB bridge (the configs in sensors.json target the KEL USB-I2C module).

2. Wire the sensor

Sensor	Adapter
TX	RX
RX	TX
GND	GND
VCC	5 V or 3.3 V — check the datasheet

ℹ️ Sensirion SEN55: leave the SEL pin (pin 5) unconnected so the sensor starts in UART mode. See SEN5x UART Protocol.

⚠️ Many PM sensors (e.g. Plantower PMS5003) need a 5 V supply but use 3.3 V logic on TX/RX. Make sure your adapter's logic level matches the sensor.

3. Connect

1. Open https://wespeakenglish.github.io/polluSensWeb/
2. Pick your sensor in the Sensor dropdown.
3. Click Connect and choose the serial port in the browser's pop-up.
4. Raw packets appear in the Log with ✅ (checksum OK) or ❌ (checksum failed).

4. Plot data

1. In Create a Chart, give the chart a name.
2. Tick the signals you want and adjust colour, thickness and tension if you like.
3. Click Create Chart. You can create as many charts as you need.

5. Save data

Click Save CSV at any time. The file contains every frame since you connected: an ISO-8601 timestamp column followed by one column per signal.

Next steps

• Your sensor isn't listed? → Adding a New Sensor
• Send data to a server? → Webhooks
• Something not working? → Troubleshooting and FAQ