Arachiver is a cross-platform tool for archiving data from Aranet4 CO2 sensors over Bluetooth LE. Aranet4 devices retain approximately 17.5 days of data with the default measurement interval. At each measurement time, it records CO₂ abundance (ppm), temperature (°C), relative humidity (%), and pressure (hPa). The Arachiver tool is oriented toward data analysis. It can output to CSV or Apache Parquet formats. While temperature and pressure are stored on-device as integers that require applying scale factors that you Just Have To Know, Arachiver applies the appropriate scale factors and stores temperature and pressure as floating-point numbers. Timestamps are UNIX timestamps.
- Install a Rust toolchain, either through your system package manager or via the officially recommended rustup tool:
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh cargo install --git https://github.com/fotonick/arachiver
The underlying Bluetooth library is btleplug, which claims to support Windows, Linux, macOS, Android, and iOS, though I have only tested macOS.
> arachiver --help
Aranet4 archiver
Usage: arachiver [OPTIONS] <COMMAND>
Commands:
device_info Print device information
readout Print the current sensor readings to stdout
archive_history_csv Save the full history to CSV
archive_history_parquet Save the full history to Parquet
help Print this message or the help of the given subcommand(s)
Options:
-d, --device <device_pattern> Select an Aranet4 device with <device_pattern> in its name; by default, the first device with 'Aranet' in its name will be used [default: Aranet]
-h, --help Print help
> arachiver device_info
Aranet4 1BA27
=============
Model number: Aranet4
Serial number: 317960113191
Hardware revision: 12
Software revision: v0.4.14
Manufacturer name: SAF Tehnika
Firmware revision: v1.4.14
> arachiver readout
Aranet4 1BA27
=============
CO₂: 926 ppm
T: 20.65°C
P: 1017.4 hPa
Humidity: 33%
Battery: 22%
Status: 1
Interval: 300 s
Ago: 255 s
> arachiver archive_history_csv
Wrote 2025-02-21T02:16:51.917392-08:00_Aranet4_1BA27_history.csv
> head -n 3 2025-02-21T02:16:51.917392-08:00_Aranet4_1BA27_history.csv
timestamp,Temperature (°C),Humidity (%),Pressure (hPa),CO₂ (ppm)
1738621029,14.90,29,999.8,592
1738621329,14.95,29,999.7,590
> arachiver archive_history_parquet
Wrote 2025-02-21T02:18:10.840587-08:00_Aranet4_1BA27_history.parquet
> parquet-tools inspect 2025-02-21T02:18:10.840587-08:00_Aranet4_1BA27_history.parquet
############ file meta data ############
created_by: parquet-rs version 54.2.0
num_columns: 5
num_rows: 5040
num_row_groups: 1
format_version: 1.0
serialized_size: 745
############ Columns ############
timestamp
temperature
humidity
pressure
co2
############ Column(timestamp) ############
name: timestamp
path: timestamp
max_definition_level: 0
max_repetition_level: 0
physical_type: INT64
logical_type: None
converted_type (legacy): NONE
compression: ZSTD (space_saved: 67%)
############ Column(temperature) ############
name: temperature
path: temperature
max_definition_level: 0
max_repetition_level: 0
physical_type: FLOAT
logical_type: None
converted_type (legacy): NONE
compression: ZSTD (space_saved: 33%)
############ Column(humidity) ############
name: humidity
path: humidity
max_definition_level: 0
max_repetition_level: 0
physical_type: INT32
logical_type: None
converted_type (legacy): NONE
compression: ZSTD (space_saved: 10%)
############ Column(pressure) ############
name: pressure
path: pressure
max_definition_level: 0
max_repetition_level: 0
physical_type: FLOAT
logical_type: None
converted_type (legacy): NONE
compression: ZSTD (space_saved: 7%)
############ Column(co2) ############
name: co2
path: co2
max_definition_level: 0
max_repetition_level: 0
physical_type: INT32
logical_type: None
converted_type (legacy): NONE
compression: ZSTD (space_saved: 12%)
The final example used parquet-tools to inspect the Parquet file.
Comparatively, Arachiver was designed with enabling data analysis as its primary focus and is not concerned with exposing every control knob.
This software is released under the MIT license.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion into this project shall be licensed as MIT, without any additional terms or conditions.