IIO sensors to D-Bus proxy
See https://developer.gnome.org/iio-sensor-proxy/1.0/ for developer information.
./configure --prefix=/usr --sysconfdir=/etc make make install
It requires libgudev and systemd (>= 233 for the accelerometer quirks).
With a GNOME 3.18 (or newer) based system, orientation changes will automatically be applied when rotating the panel, ambient light will be used to change the screen brightness, and Geoclue will be able to read the compass data to show the direction in Maps.
Note that a number of kernel bugs will prevent it from working correctly on some machines so please make sure to use the latest upstream kernel (kernel crashes on the Surface Pro, sensor failing to work after suspend on the Yoga Pro, etc.).
You can verify that sensors are detected by running udevadm info --export-db
and checking for an output resembling this one:
P: /devices/platform/80860F41:04/i2c-12/i2c-BMA250E:00/iio:device0 N: iio:device0 E: DEVNAME=/dev/iio:device0 E: DEVPATH=/devices/platform/80860F41:04/i2c-12/i2c-BMA250E:00/iio:device0 E: DEVTYPE=iio_device E: MAJOR=249 E: MINOR=0 E: SUBSYSTEM=iio E: SYSTEMD_WANTS=iio-sensor-proxy.service E: TAGS=:systemd: E: USEC_INITIALIZED=7750292
You can now check whether a sensor is detected by running:
gdbus introspect --system --dest net.hadess.SensorProxy --object-path /net/hadess/SensorProxy
After that, use monitor-sensor to see changes in the ambient light sensor
or the accelerometer. Note that compass changes are only available to GeoClue
but if you need to ensure that GeoClue is getting correct data you can run:
su -s /bin/sh geoclue -c monitor-sensor
If that doesn't work, please file an issue, make sure any running iio-sensor-proxy
has been stopped:
systemctl stop iio-sensor-proxy.service
and attach the output of:
G_MESSAGES_DEBUG=all /usr/sbin/iio-sensor-proxy
running as root.
When the accelerometer is not mounted the same way as the screen, we need to modify the readings from the accelerometer to make sure that the computed orientation matches the screen one.
iio-sensor-proxy reads this information from the device's
ACCEL_MOUNT_MATRIX udev property. See 60-sensor.hwdb
for details.
Only the Geoclue daemon (as the geoclue user) is allowed to access the net.hadess.SensorProxy.Compass
interface, the results of which it will propagate to clients along with positional information.
If your device does not contain a compass, you can run tests with:
- If your device does not contain a real compass:
- Add FAKE_COMPASS=1 to the environment of iio-sensor-proxy.service if your device does not contain a real one
- Run the daemon manually with systemctl start iio-sensor-proxy.service
- Verify that iio-sensor-proxy is running with systemctl or ps
- As root, get a shell as the geoclue user with su -s /bin/bash geoclue
- Run, as the geoclue user, monitor-sensor
Every Linux kernel from 4.3 up to version 4.12 had a bug that made made iio-sensor-proxy fail to see any events coming from sensors until the sensor was power-cycled (unplugged and replugged, or suspended and resumed).
The bug was finally fixed in this commit in the upstream kernel and backported to stable releases. If you experience unresponsive sensors, ask your distributor to make sure this patch was applied to the version you're using.