SGP30

Connects over

I²C

Address

0x58

Made by

Sensirion

Datasheet

sensirion.com

Use it

hardware {
    device sgp30: SGP30
}

every 1s {
    let value: int = sgp30.baseline_eco2()
    log("sgp30", "baseline_eco2={value}")
}

On its own, the declaration puts the SGP30 on the first I²C bus (SDA 21, SCL 22 on the ESP32) at 0x58. To choose the pins or the address, declare the bus and attach the device: device sgp30: SGP30 on i2c0 at 0x58 with i2c i2c0(sda: 21, scl: 22).

Methods

• sgp30.baseline_eco2() -> int

  Current eCO2 baseline, to save to storage.

• sgp30.baseline_tvoc() -> int

  Current TVOC baseline, to save to storage.

• sgp30.eco2() -> int

  Equivalent CO2 in ppm (400-60000).

• sgp30.ready() -> bool

  False during the 15 s warm-up after init, or if the last read failed.

• sgp30.set_baseline(eco2: int, tvoc: int)

  Restore baselines saved earlier (call in setup, after a fresh boot).

• sgp30.set_humidity(temp_c: float, rh: float)

  Humidity compensation from air temperature (°C) and relative humidity (%), e.g. from an SHT31 or BME280. Call whenever they change.

• sgp30.tvoc() -> int

  Total volatile organic compounds in ppb (0-60000).

Wiring

Specifications

Current

48 mA while measuring

Eco2

400 - 60000 ppm

Sample rate

1 Hz (the on-chip algorithm expects it)

Tvoc

0 - 60000 ppb

Voltage

1.62V - 1.98V die (breakouts regulate 3.3V/5V)

Tips

• Read it once per second: the baseline algorithm depends on a steady 1 Hz rate. The driver measures at most once per second however often you call it.
• For the first 15 s after power-up it reports 400 ppm eCO2 and 0 ppb TVOC (warming up); ready() is false until then.
• Save baseline_eco2()/baseline_tvoc() to storage about once an hour and restore them with set_baseline() at boot; a stored baseline older than 7 days should be discarded.
• eCO2 is estimated from hydrogen, not measured; use an SCD4x for true CO2.

Alternatives worth knowing:

• ENS160: Adds an AQI 1-5 index; similar TVOC/eCO2 estimates.
• SCD4x: True NDIR CO2 in ppm.