axR

Interfacing and retrieving data from accelerometer devices in R

R Package
Actigraphy
Hardware
Open Source
Device discovery, status, settings, and data download for Axivity AX3/AX6 accelerometer devices, plus direct parsing of .cwa files and Condor Instruments ActTrust .txt exports into a tidy epoch shape.
Published

July 22, 2026

About

axR talks to Axivity AX3/AX6 accelerometers over USB: discovering connected devices, querying and setting status/configuration, and downloading recorded .cwa files. It also parses those .cwa files directly, and Condor Instruments ActTrust .txt actigraphy exports, into the same tidy epoch shape.

Rather than reimplementing the Axivity serial protocol directly, axR wraps the Open Movement Project’s OMAPI C library — the same library behind Axivity’s own OmGui software — giving it maintained, platform-specific device discovery (IOKit/DiskArbitration on macOS, SetupAPI on Windows, udev on Linux) rather than a hand-rolled equivalent.

axR is deliberately mostly a “dumb pipe”: it talks to the device and moves bytes, leaving higher-level actigraphy analysis to downstream packages such as mrpheus or zeitR.

Features

  • Discovery — axivity_discover()
  • Status — battery, self-test, memory health, live accelerometer reading, RTC get/set, LED colour, anti-tamper lock, ECC flag
  • Settings — delayed activation window, session ID, metadata scratch buffer, accelerometer rate/range
  • axivity_stage_device() — one-call deployment staging: config, deployment window, session ID, and metadata, committed via axivity_reset()
  • Download — axivity_download(), backed by OMAPI’s own background download thread, with a plain-file-copy fallback via axivity_copy_data()
  • axivity_read_cwa() — parse a .cwa/AX6 file directly into a tibble, no live device required
  • read_acttrust() — parse a Condor Instruments ActTrust .txt export into the same tidy epoch shape, as a device-agnostic actigraphy import layer

Status

axR has not been fully verified against real hardware. Live-device testing was performed on macOS and a real AX3. timestamp/x/y/z/device_id from axivity_read_cwa() have been verified correct against a real recording; temperature_c has not, and is likely wrong on at least some hardware revisions. Not tested against an AX6.