SCD30 (CO2 sensor)

Go/TinyGo driver for Sensirion SCD30: ambient CO2, humidity, and temperature sensor module.

Driver

Driver implements all commands described in the official interface description document.

Hardware details

• driver communicates over I2C interface (address is 0x61)
• product page
• datasheet
• interface description
• buy sensor from SparkFun.

Example

Driver can work with any Go program that provides I2C interface like this:

type I2C interface {
	Tx(addr uint16, w, r []byte) error
}

This is TinyGo example that uses machine package's I2C to control SCD30:

package main

import (
  "time"

  "machine"

  "github.com/antonfisher/scd30"
)

func main() {
  bus := machine.I2C0
  err := bus.Configure(machine.I2CConfig{})
  if err != nil {
    println("could not configure I2C:", err)
    return
  }

  // Create driver for SCD30.
  co2sensor := scd30.New(bus)

  // Read sensor's firmware version.
  version, err := co2sensor.GetSoftwareVersion()
  if err != nil {
    println("failed to get software version:", err)
    return
  }
  println("software version:", version)

  // Start continuous measurement without provided ambient pressure
  // (should be ON by default on a new chip with 2 seconds interval).
  err = co2sensor.StartContinuousMeasurement(uint16(0))
  if err != nil {
    println("ERROR: co2 sensor: failed to trigger continuous measurement:", err)
    return
  }

  // Check is the sensor has data, and read it every 2 seconds.
  for {
    hasDataReady, err := co2sensor.HasDataReady()
    if err != nil {
      println("failed to check for data:", err)
    } else if hasDataReady {
      measurement, err := co2sensor.ReadMeasurement()
      if err != nil {
        println("failed to read measurement:", err)
      } else {
        //TODO can use println?
        fmt.Printf("measurement: %s\n\r", measurement.String())
      }
    } else {
      println("skipping, no data...")
    }

    time.Sleep(time.Second * 2)
  }
}

This example was tested on nRF52840 controller. Command to flash it:

tinygo flash -target=feather-nrf52840 main.go

Show the output in the terminal:

# find out dev to use
ls -l /dev/cu.*

# use `Control+A Control+\ y [Enter]` to exit
screen /dev/cu.usbmodem144101 19200

For more configuration options see sensor's official interface description document and driver reference.

Inspired by

• Sensirion's official driver: https://github.com/Sensirion/embedded-scd/
• SparkFun SCD30 Arduino driver: https://github.com/sparkfun/SparkFun_SCD30_Arduino_Library
• @pvainio's Go driver: https://github.com/pvainio/scd30

License

MIT License