.. SPDX-License-Identifier: GPL-2.0

================ ADIS16480 driver

This driver supports Analog Device's IMUs on SPI bus.

Supported devices ====================

ADIS16375 <https://www.analog.com/ADIS16375>_
ADIS16480 <https://www.analog.com/ADIS16480>_
ADIS16485 <https://www.analog.com/ADIS16485>_
ADIS16488 <https://www.analog.com/ADIS16488>_
ADIS16490 <https://www.analog.com/ADIS16490>_
ADIS16495 <https://www.analog.com/ADIS16495>_
ADIS16497 <https://www.analog.com/ADIS16497>_
ADIS16545 <https://www.analog.com/ADIS16545>_
ADIS16547 <https://www.analog.com/ADIS16547>_

Each supported device is a complete inertial system that includes a triaxial gyroscope and a triaxial accelerometer. Each inertial sensor in device combines with signal conditioning that optimizes dynamic performance. The factory calibration characterizes each sensor for sensitivity, bias, and alignment. As a result, each sensor has its own dynamic compensation formulas that provide accurate sensor measurements.

Device attributes ====================

Accelerometer, gyroscope measurements are always provided. Furthermore, the driver offers the capability to retrieve the delta angle and the delta velocity measurements computed by the device.

The delta angle measurements represent a calculation of angular displacement between each sample update, while the delta velocity measurements represent a calculation of linear velocity change between each sample update.

Finally, temperature data are provided which show a coarse measurement of the temperature inside of the IMU device. This data is most useful for monitoring relative changes in the thermal environment.

ADIS16480 and ADIS16488 also provide access to barometric pressure data and triaxial magnetometer measurements.

Each IIO device, has a device folder under /sys/bus/iio/devices/iio:deviceX, where X is the IIO index of the device. Under these folders reside a set of device files, depending on the characteristics and features of the hardware device in questions. These files are consistently generalized and documented in the IIO ABI documentation.

The following tables show the adis16480 related device files, found in the specific device folder path /sys/bus/iio/devices/iio:deviceX.

Available only for ADIS16480 and ADIS16488:

+------------------------------------------+---------------------------------------------------------+ | 3-Axis Magnetometer related device files | Description | +------------------------------------------+---------------------------------------------------------+ | in_magn_scale | Scale for the magnetometer channels. | +------------------------------------------+---------------------------------------------------------+ | in_magn_x_calibbias | Calibration offset for the X-axis magnetometer channel. | +------------------------------------------+---------------------------------------------------------+ | in_magn_x_filter_low_pass_3db_frequency | Bandwidth for the X-axis magnetometer channel. | +------------------------------------------+---------------------------------------------------------+ | in_magn_x_raw | Raw X-axis magnetometer channel value. | +------------------------------------------+---------------------------------------------------------+ | in_magn_y_calibbias | Calibration offset for the Y-axis magnetometer channel. | +------------------------------------------+---------------------------------------------------------+ | in_magn_y_filter_low_pass_3db_frequency | Bandwidth for the Y-axis magnetometer channel. | +------------------------------------------+---------------------------------------------------------+ | in_magn_y_raw | Raw Y-axis magnetometer channel value. | +------------------------------------------+---------------------------------------------------------+ | in_magn_z_calibbias | Calibration offset for the Z-axis magnetometer channel. | +------------------------------------------+---------------------------------------------------------+ | in_magn_z_filter_low_pass_3db_frequency | Bandwidth for the Z-axis magnetometer channel. | +------------------------------------------+---------------------------------------------------------+ | in_magn_z_raw | Raw Z-axis magnetometer channel value. | +------------------------------------------+---------------------------------------------------------+

+------------------------------------------+-----------------------------------------------------+ | Barometric pressure sensor related files | Description | +------------------------------------------+-----------------------------------------------------+ | in_pressure0_calibbias | Calibration offset for barometric pressure channel. | +------------------------------------------+-----------------------------------------------------+ | in_pressure0_raw | Raw barometric pressure channel value. | +------------------------------------------+-----------------------------------------------------+ | in_pressure0_scale | Scale for the barometric pressure sensor channel. | +------------------------------------------+-----------------------------------------------------+

Available for all supported devices:

+-------------------------------------------+----------------------------------------------------------+ | 3-Axis Accelerometer related device files | Description | +-------------------------------------------+----------------------------------------------------------+ | in_accel_scale | Scale for the accelerometer channels. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_x_calibbias | Calibration offset for the X-axis accelerometer channel. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_x_calibscale | Calibration scale for the X-axis accelerometer channel. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_x_filter_low_pass_3db_frequency | Bandwidth for the X-axis accelerometer channel. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_x_raw | Raw X-axis accelerometer channel value. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_y_calibbias | Calibration offset for the Y-axis accelerometer channel. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_y_calibscale | Calibration scale for the Y-axis accelerometer channel. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_y_filter_low_pass_3db_frequency | Bandwidth for the Y-axis accelerometer channel. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_y_raw | Raw Y-axis accelerometer channel value. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_z_calibbias | Calibration offset for the Z-axis accelerometer channel. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_z_calibscale | Calibration scale for the Z-axis accelerometer channel. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_z_filter_low_pass_3db_frequency | Bandwidth for the Z-axis accelerometer channel. | +-------------------------------------------+----------------------------------------------------------+ | in_accel_z_raw | Raw Z-axis accelerometer channel value. | +-------------------------------------------+----------------------------------------------------------+ | in_deltavelocity_scale | Scale for delta velocity channels. | +-------------------------------------------+----------------------------------------------------------+ | in_deltavelocity_x_raw | Raw X-axis delta velocity channel value. | +-------------------------------------------+----------------------------------------------------------+ | in_deltavelocity_y_raw | Raw Y-axis delta velocity channel value. | +-------------------------------------------+----------------------------------------------------------+ | in_deltavelocity_z_raw | Raw Z-axis delta velocity channel value. | +-------------------------------------------+----------------------------------------------------------+

+--------------------------------------------+------------------------------------------------------+ | 3-Axis Gyroscope related device files | Description | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_scale | Scale for the gyroscope channels. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_x_calibbias | Calibration offset for the X-axis gyroscope channel. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_x_calibscale | Calibration scale for the X-axis gyroscope channel. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_x_filter_low_pass_3db_frequency | Bandwidth for the X-axis gyroscope channel. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_x_raw | Raw X-axis gyroscope channel value. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_y_calibbias | Calibration offset for the Y-axis gyroscope channel. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_y_calibscale | Calibration scale for the Y-axis gyroscope channel. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_y_filter_low_pass_3db_frequency | Bandwidth for the Y-axis gyroscope channel. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_y_raw | Raw Y-axis gyroscope channel value. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_z_calibbias | Calibration offset for the Z-axis gyroscope channel. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_z_calibscale | Calibration scale for the Z-axis gyroscope channel. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_z_filter_low_pass_3db_frequency | Bandwidth for the Z-axis gyroscope channel. | +--------------------------------------------+------------------------------------------------------+ | in_anglvel_z_raw | Raw Z-axis gyroscope channel value. | +--------------------------------------------+------------------------------------------------------+ | in_deltaangl_scale | Scale for delta angle channels. | +--------------------------------------------+------------------------------------------------------+ | in_deltaangl_x_raw | Raw X-axis delta angle channel value. | +--------------------------------------------+------------------------------------------------------+ | in_deltaangl_y_raw | Raw Y-axis delta angle channel value. | +--------------------------------------------+------------------------------------------------------+ | in_deltaangl_z_raw | Raw Z-axis delta angle channel value. | +--------------------------------------------+------------------------------------------------------+

+----------------------------------+-------------------------------------------+ | Temperature sensor related files | Description | +----------------------------------+-------------------------------------------+ | in_temp0_raw | Raw temperature channel value. | +----------------------------------+-------------------------------------------+ | in_temp0_offset | Offset for the temperature sensor channel.| +----------------------------------+-------------------------------------------+ | in_temp0_scale | Scale for the temperature sensor channel. | +----------------------------------+-------------------------------------------+

+-------------------------------+---------------------------------------------------------+ | Miscellaneous device files | Description | +-------------------------------+---------------------------------------------------------+ | name | Name of the IIO device. | +-------------------------------+---------------------------------------------------------+ | sampling_frequency | Currently selected sample rate. | +-------------------------------+---------------------------------------------------------+

The following table shows the adis16480 related device debug files, found in the specific device debug folder path /sys/kernel/debug/iio/iio:deviceX.

+----------------------+-------------------------------------------------------------------------+ | Debugfs device files | Description | +----------------------+-------------------------------------------------------------------------+ | serial_number | The serial number of the chip in hexadecimal format. | +----------------------+-------------------------------------------------------------------------+ | product_id | Chip specific product id (e.g. 16480, 16488, 16545, etc.). | +----------------------+-------------------------------------------------------------------------+ | flash_count | The number of flash writes performed on the device. | +----------------------+-------------------------------------------------------------------------+ | firmware_revision | String containing the firmware revision in the following format ##.##. | +----------------------+-------------------------------------------------------------------------+ | firmware_date | String containing the firmware date in the following format mm-dd-yyyy. | +----------------------+-------------------------------------------------------------------------+

Channels processed values

A channel value can be read from its _raw attribute. The value returned is the raw value as reported by the devices. To get the processed value of the channel, apply the following formula:

.. code-block:: bash

    processed value = (_raw + _offset) * _scale

Where _offset and _scale are device attributes. If no _offset attribute is present, simply assume its value is 0.

The adis16480 driver offers data for 7 types of channels, the table below shows the measurement units for the processed value, which are defined by the IIO framework:

Usage examples

Show device name:

.. code-block:: bash

root:/sys/bus/iio/devices/iio:device0> cat name
    adis16545-1

Show accelerometer channels value:

.. code-block:: bash

    root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_raw
    1376728
    root:/sys/bus/iio/devices/iio:device0> cat in_accel_y_raw
    4487621
    root:/sys/bus/iio/devices/iio:device0> cat in_accel_z_raw
    262773792
    root:/sys/bus/iio/devices/iio:device0> cat in_accel_scale
    0.000000037

X-axis acceleration = in_accel_x_raw * in_accel_scale = 0.050938936 m/s^2
Y-axis acceleration = in_accel_y_raw * in_accel_scale = 0.166041977 m/s^2
Z-axis acceleration = in_accel_z_raw * in_accel_scale = 9.722630304 m/s^2

Show gyroscope channels value:

.. code-block:: bash

    root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_x_raw
    -1041702
    root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_raw
    -273013
    root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_z_raw
    2745116
    root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_scale
    0.000000001

X-axis angular velocity = in_anglvel_x_raw * in_anglvel_scale = −0.001041702 rad/s
Y-axis angular velocity = in_anglvel_y_raw * in_anglvel_scale = −0.000273013 rad/s
Z-axis angular velocity = in_anglvel_z_raw * in_anglvel_scale = 0.002745116 rad/s

Set calibration offset for accelerometer channels:

.. code-block:: bash

    root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_calibbias
    0

    root:/sys/bus/iio/devices/iio:device0> echo 5000 > in_accel_x_calibbias
    root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_calibbias
    5000

Set calibration offset for gyroscope channels:

.. code-block:: bash

    root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_calibbias
    0

    root:/sys/bus/iio/devices/iio:device0> echo -5000 > in_anglvel_y_calibbias
    root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_calibbias
    -5000

Set sampling frequency:

.. code-block:: bash

root:/sys/bus/iio/devices/iio:device0> cat sampling_frequency
    4250.000000

    root:/sys/bus/iio/devices/iio:device0> echo 1000 > sampling_frequency
    1062.500000

Set bandwidth for accelerometer channels:

.. code-block:: bash

    root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_filter_low_pass_3db_frequency
    0

    root:/sys/bus/iio/devices/iio:device0> echo 300 > in_accel_x_filter_low_pass_3db_frequency
    root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_filter_low_pass_3db_frequency
    300

Show serial number:

.. code-block:: bash

    root:/sys/kernel/debug/iio/iio:device0> cat serial_number
    0x000c

Show product id:

.. code-block:: bash

    root:/sys/kernel/debug/iio/iio:device0> cat product_id
    16545

Show flash count:

.. code-block:: bash

    root:/sys/kernel/debug/iio/iio:device0> cat flash_count
    88

Show firmware revision:

.. code-block:: bash

    root:/sys/kernel/debug/iio/iio:device0> cat firmware_revision
    1.4

Show firmware date:

.. code-block:: bash

    root:/sys/kernel/debug/iio/iio:device0> cat firmware_date
    09-23-2023

3. Device buffers

This driver supports IIO buffers.

All devices support retrieving the raw acceleration, gyroscope and temperature measurements using buffers.

The following device families also support retrieving the delta velocity, delta angle and temperature measurements using buffers:

ADIS16545
ADIS16547

However, when retrieving acceleration or gyroscope data using buffers, delta readings will not be available and vice versa. This is because the device only allows to read either acceleration and gyroscope data or delta velocity and delta angle data at a time and switching between these two burst data selection modes is time consuming.

Usage examples

Set device trigger in current_trigger, if not already set:

.. code-block:: bash

    root:/sys/bus/iio/devices/iio:device0> cat trigger/current_trigger

    root:/sys/bus/iio/devices/iio:device0> echo adis16545-1-dev0 > trigger/current_trigger
    root:/sys/bus/iio/devices/iio:device0> cat trigger/current_trigger
    adis16545-1-dev0

Select channels for buffer read:

.. code-block:: bash

    root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_x_en
    root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_y_en
    root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_z_en
    root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_temp0_en

Set the number of samples to be stored in the buffer:

.. code-block:: bash

    root:/sys/bus/iio/devices/iio:device0> echo 10 > buffer/length

Enable buffer readings:

.. code-block:: bash

    root:/sys/bus/iio/devices/iio:device0> echo 1 > buffer/enable

Obtain buffered data::

root:/sys/bus/iio/devices/iio:device0> hexdump -C /dev/iio:device0 ... 00006aa0 09 62 00 00 ff ff fc a4 00 00 01 69 00 03 3c 08 |.b.........i..<.| 00006ab0 09 61 00 00 00 00 02 96 00 00 02 8f 00 03 37 50 |.a............7P| 00006ac0 09 61 00 00 00 00 12 3d 00 00 0b 89 00 03 2c 0b |.a.....=......,.| 00006ad0 09 61 00 00 00 00 1e dc 00 00 16 dd 00 03 25 bf |.a............%.| 00006ae0 09 61 00 00 00 00 1e e3 00 00 1b bf 00 03 27 0b |.a............'.| 00006af0 09 61 00 00 00 00 15 50 00 00 19 44 00 03 30 fd |.a.....P...D..0.| 00006b00 09 61 00 00 00 00 09 0e 00 00 14 41 00 03 3d 7f |.a.........A..=.| 00006b10 09 61 00 00 ff ff ff f0 00 00 0e bc 00 03 48 d0 |.a............H.| 00006b20 09 63 00 00 00 00 00 9f 00 00 0f 37 00 03 4c fe |.c.........7..L.| 00006b30 09 64 00 00 00 00 0b f6 00 00 18 92 00 03 43 22 |.d............C"| 00006b40 09 64 00 00 00 00 18 df 00 00 22 33 00 03 33 ab |.d........"3..3.| 00006b50 09 63 00 00 00 00 1e 81 00 00 26 be 00 03 29 60 |.c........&...)`| 00006b60 09 63 00 00 00 00 1b 13 00 00 22 2f 00 03 23 91 |.c........"/..#.| ...

See Documentation/iio/iio_devbuf.rst for more information about how buffered data is structured.

IIO Interfacing Tools ========================

See Documentation/iio/iio_tools.rst for the description of the available IIO interfacing tools.