semvec/pypi-packages huggingface dataset:
micropython-scd30 0.2.0
MicroPython I2C driver for SCD30 CO2 sensor module
License: MIT
Keywords: scd30,co2,temperature,humidity,micropython,i2c

# Sensirion SCD30 CO² Sensor I2C driver for MicroPython

Sensirion SCD30 is a CO², Humidity and Temperature sensor on a module. This is
a I2C driver written in Python 3 for MicroPython.

## Getting Started

### Prerequisites

* Sensirion SCD30 Sensor Module
* MicroPython board with I2C interface

### Wiring

Wire the I2C bus to the I2C bus on your MicroPython board. This is an example
using the Pyboard D:

| Pyboard       | SCD30         |
| ------------- |---------------|
| X15 (3V3)     | VDD           |
| X14 (GND)     | GND           |
| X9            | TX/SCL        |
| X10           | RX/SDA        |

### Usage

This example reads the measurements in a continous loop:

```
import time
from machine import I2C, Pin
from scd30 import SCD30

i2cbus = I2C(1)
scd30 = SCD30(i2c, 0x61)

while True:
    # Wait for sensor data to be ready to read (by default every 2 seconds)
    while scd30.get_status_ready() != 1:
        time.sleep_ms(200)
    scd30.read_measurement()
```

Note that the CO² sensor needs some time to stabilize. Therefor the sensor
should be kept powered to achieve a reasonable measurement interval (e.g. <5
minutes). To save power the sensors measurement inverval can be tweaked. See
also the [Low Power Mode for SCD30](https://docs-emea.rs-online.com/webdocs/16c9/0900766b816c9dc7.pdf)
application note.

### Calibration

The CO² sensor has two modes of calibration: FRC (Forced Recalibration) or ASC
(Automatic Self-Calibration). This only describes the former.

Essentially the sensor is already calibrated at factory. However, when setting a
new measurement interval recalibration might be necessary. The process is to
bring the sensor into a controlled environment (e.g. outside) and set the known
value at that environment (e.g. 400ppm). From what I understand ASC does
essentially the same, just assumes that the lowest values over a certain periode
are "outside values"...

Also note that the temperature sensor suffers from heating effects on the PCB.
When the sensor operates in 2 second interval the heating is about 3°C. I
usually run the sensor at 30 seconds interval and observed a heating of 2°C. The
offset is subtracted from the measured temperature! To set a new offset, take
the old offset into account!

## Built With

* [MicroPython](http://micropython.org/)
* [SCD30 Sensor Module](https://www.sensirion.com/en/environmental-sensors/carbon-dioxide-sensors-co2/)

## License

This project is licensed under the MIT License - see the
[LICENSE](LICENSE) file for details