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1.. SPDX-License-Identifier: GPL-2.02 3================4ADIS16475 driver5================6 7This driver supports Analog Device's IMUs on SPI bus.8 91. Supported devices10====================11 12* `ADIS16465 <https://www.analog.com/ADIS16465>`_13* `ADIS16467 <https://www.analog.com/ADIS16467>`_14* `ADIS16470 <https://www.analog.com/ADIS16470>`_15* `ADIS16475 <https://www.analog.com/ADIS16475>`_16* `ADIS16477 <https://www.analog.com/ADIS16477>`_17* `ADIS16500 <https://www.analog.com/ADIS16500>`_18* `ADIS16505 <https://www.analog.com/ADIS16505>`_19* `ADIS16507 <https://www.analog.com/ADIS16507>`_20 21Each supported device is a precision, miniature microelectromechanical system22(MEMS) inertial measurement unit (IMU) that includes a triaxial gyroscope and a23triaxial accelerometer. Each inertial sensor in the IMU device combines with24signal conditioning that optimizes dynamic performance. The factory calibration25characterizes each sensor for sensitivity, bias, alignment, linear acceleration26(gyroscope bias), and point of percussion (accelerometer location). As a result,27each sensor has dynamic compensation formulas that provide accurate sensor28measurements over a broad set of conditions.29 302. Device attributes31====================32 33Accelerometer, gyroscope measurements are always provided. Furthermore, the34driver offers the capability to retrieve the delta angle and the delta velocity35measurements computed by the device.36 37The delta angle measurements represent a calculation of angular displacement38between each sample update, while the delta velocity measurements represent a39calculation of linear velocity change between each sample update.40 41Finally, temperature data are provided which show a coarse measurement of42the temperature inside of the IMU device. This data is most useful for43monitoring relative changes in the thermal environment.44 45The signal chain of each inertial sensor (accelerometers and gyroscopes)46includes the application of unique correction formulas, which are derived from47extensive characterization of bias, sensitivity, alignment, response to linear48acceleration (gyroscopes), and point of percussion (accelerometer location)49over a temperature range of −40°C to +85°C, for each ADIS device. These50correction formulas are not accessible, but users do have the opportunity to51adjust the bias for each sensor individually through the calibbias attribute.52 53Each IIO device, has a device folder under ``/sys/bus/iio/devices/iio:deviceX``,54where X is the IIO index of the device. Under these folders reside a set of55device files, depending on the characteristics and features of the hardware56device in questions. These files are consistently generalized and documented in57the IIO ABI documentation.58 59The following tables show the adis16475 related device files, found in the60specific device folder path ``/sys/bus/iio/devices/iio:deviceX``.61 62+-------------------------------------------+----------------------------------------------------------+63| 3-Axis Accelerometer related device files | Description |64+-------------------------------------------+----------------------------------------------------------+65| in_accel_scale | Scale for the accelerometer channels. |66+-------------------------------------------+----------------------------------------------------------+67| in_accel_x_calibbias | Calibration offset for the X-axis accelerometer channel. |68+-------------------------------------------+----------------------------------------------------------+69| in_accel_x_raw | Raw X-axis accelerometer channel value. |70+-------------------------------------------+----------------------------------------------------------+71| in_accel_y_calibbias | Calibration offset for the Y-axis accelerometer channel. |72+-------------------------------------------+----------------------------------------------------------+73| in_accel_y_raw | Raw Y-axis accelerometer channel value. |74+-------------------------------------------+----------------------------------------------------------+75| in_accel_z_calibbias | Calibration offset for the Z-axis accelerometer channel. |76+-------------------------------------------+----------------------------------------------------------+77| in_accel_z_raw | Raw Z-axis accelerometer channel value. |78+-------------------------------------------+----------------------------------------------------------+79| in_deltavelocity_scale | Scale for delta velocity channels. |80+-------------------------------------------+----------------------------------------------------------+81| in_deltavelocity_x_raw | Raw X-axis delta velocity channel value. |82+-------------------------------------------+----------------------------------------------------------+83| in_deltavelocity_y_raw | Raw Y-axis delta velocity channel value. |84+-------------------------------------------+----------------------------------------------------------+85| in_deltavelocity_z_raw | Raw Z-axis delta velocity channel value. |86+-------------------------------------------+----------------------------------------------------------+87 88+---------------------------------------+------------------------------------------------------+89| 3-Axis Gyroscope related device files | Description |90+---------------------------------------+------------------------------------------------------+91| in_anglvel_scale | Scale for the gyroscope channels. |92+---------------------------------------+------------------------------------------------------+93| in_anglvel_x_calibbias | Calibration offset for the X-axis gyroscope channel. |94+---------------------------------------+------------------------------------------------------+95| in_anglvel_x_raw | Raw X-axis gyroscope channel value. |96+---------------------------------------+------------------------------------------------------+97| in_anglvel_y_calibbias | Calibration offset for the Y-axis gyroscope channel. |98+---------------------------------------+------------------------------------------------------+99| in_anglvel_y_raw | Raw Y-axis gyroscope channel value. |100+---------------------------------------+------------------------------------------------------+101| in_anglvel_z_calibbias | Calibration offset for the Z-axis gyroscope channel. |102+---------------------------------------+------------------------------------------------------+103| in_anglvel_z_raw | Raw Z-axis gyroscope channel value. |104+---------------------------------------+------------------------------------------------------+105| in_deltaangl_scale | Scale for delta angle channels. |106+---------------------------------------+------------------------------------------------------+107| in_deltaangl_x_raw | Raw X-axis delta angle channel value. |108+---------------------------------------+------------------------------------------------------+109| in_deltaangl_y_raw | Raw Y-axis delta angle channel value. |110+---------------------------------------+------------------------------------------------------+111| in_deltaangl_z_raw | Raw Z-axis delta angle channel value. |112+---------------------------------------+------------------------------------------------------+113 114+----------------------------------+-------------------------------------------+115| Temperature sensor related files | Description |116+----------------------------------+-------------------------------------------+117| in_temp0_raw | Raw temperature channel value. |118+----------------------------------+-------------------------------------------+119| in_temp0_scale | Scale for the temperature sensor channel. |120+----------------------------------+-------------------------------------------+121 122+-------------------------------+---------------------------------------------------------+123| Miscellaneous device files | Description |124+-------------------------------+---------------------------------------------------------+125| name | Name of the IIO device. |126+-------------------------------+---------------------------------------------------------+127| sampling_frequency | Currently selected sample rate. |128+-------------------------------+---------------------------------------------------------+129| filter_low_pass_3db_frequency | Bandwidth for the accelerometer and gyroscope channels. |130+-------------------------------+---------------------------------------------------------+131 132The following table shows the adis16475 related device debug files, found in the133specific device debug folder path ``/sys/kernel/debug/iio/iio:deviceX``.134 135+----------------------+-------------------------------------------------------------------------+136| Debugfs device files | Description |137+----------------------+-------------------------------------------------------------------------+138| serial_number | The serial number of the chip in hexadecimal format. |139+----------------------+-------------------------------------------------------------------------+140| product_id | Chip specific product id (e.g. 16475, 16500, 16505, etc.). |141+----------------------+-------------------------------------------------------------------------+142| flash_count | The number of flash writes performed on the device. |143+----------------------+-------------------------------------------------------------------------+144| firmware_revision | String containing the firmware revision in the following format ##.##. |145+----------------------+-------------------------------------------------------------------------+146| firmware_date | String containing the firmware date in the following format mm-dd-yyyy. |147+----------------------+-------------------------------------------------------------------------+148 149Channels processed values150-------------------------151 152A channel value can be read from its _raw attribute. The value returned is the153raw value as reported by the devices. To get the processed value of the channel,154apply the following formula:155 156.. code-block:: bash157 158 processed value = (_raw + _offset) * _scale159 160Where _offset and _scale are device attributes. If no _offset attribute is161present, simply assume its value is 0.162 163The adis16475 driver offers data for 5 types of channels, the table below shows164the measurement units for the processed value, which are defined by the IIO165framework:166 167+-------------------------------------+---------------------------+168| Channel type | Measurement unit |169+-------------------------------------+---------------------------+170| Acceleration on X, Y, and Z axis | Meters per Second squared |171+-------------------------------------+---------------------------+172| Angular velocity on X, Y and Z axis | Radians per second |173+-------------------------------------+---------------------------+174| Delta velocity on X. Y, and Z axis | Meters per Second |175+-------------------------------------+---------------------------+176| Delta angle on X, Y, and Z axis | Radians |177+-------------------------------------+---------------------------+178| Temperature | Millidegrees Celsius |179+-------------------------------------+---------------------------+180 181Usage examples182--------------183 184Show device name:185 186.. code-block:: bash187 188 root:/sys/bus/iio/devices/iio:device0> cat name189 adis16505-2190 191Show accelerometer channels value:192 193.. code-block:: bash194 195 root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_raw196 -275924197 root:/sys/bus/iio/devices/iio:device0> cat in_accel_y_raw198 -30142222199 root:/sys/bus/iio/devices/iio:device0> cat in_accel_z_raw200 261265769201 root:/sys/bus/iio/devices/iio:device0> cat in_accel_scale202 0.000000037203 204- X-axis acceleration = in_accel_x_raw * in_accel_scale = −0.010209188 m/s^2205- Y-axis acceleration = in_accel_y_raw * in_accel_scale = −1.115262214 m/s^2206- Z-axis acceleration = in_accel_z_raw * in_accel_scale = 9.666833453 m/s^2207 208Show gyroscope channels value:209 210.. code-block:: bash211 212 root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_x_raw213 -3324626214 root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_raw215 1336980216 root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_z_raw217 -602983218 root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_scale219 0.000000006220 221- X-axis angular velocity = in_anglvel_x_raw * in_anglvel_scale = −0.019947756 rad/s222- Y-axis angular velocity = in_anglvel_y_raw * in_anglvel_scale = 0.00802188 rad/s223- Z-axis angular velocity = in_anglvel_z_raw * in_anglvel_scale = −0.003617898 rad/s224 225Set calibration offset for accelerometer channels:226 227.. code-block:: bash228 229 root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_calibbias230 0231 232 root:/sys/bus/iio/devices/iio:device0> echo 5000 > in_accel_x_calibbias233 root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_calibbias234 5000235 236Set calibration offset for gyroscope channels:237 238.. code-block:: bash239 240 root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_calibbias241 0242 243 root:/sys/bus/iio/devices/iio:device0> echo -5000 > in_anglvel_y_calibbias244 root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_calibbias245 -5000246 247Set sampling frequency:248 249.. code-block:: bash250 251 root:/sys/bus/iio/devices/iio:device0> cat sampling_frequency252 2000.000000253 254 root:/sys/bus/iio/devices/iio:device0> echo 1000 > sampling_frequency255 1000.000000256 257Set bandwidth for accelerometer and gyroscope:258 259.. code-block:: bash260 261 root:/sys/bus/iio/devices/iio:device0> cat filter_low_pass_3db_frequency262 720263 264 root:/sys/bus/iio/devices/iio:device0> echo 360 > filter_low_pass_3db_frequency265 root:/sys/bus/iio/devices/iio:device0> cat filter_low_pass_3db_frequency266 360267 268Show serial number:269 270.. code-block:: bash271 272 root:/sys/kernel/debug/iio/iio:device0> cat serial_number273 0x04f9274 275Show product id:276 277.. code-block:: bash278 279 root:/sys/kernel/debug/iio/iio:device0> cat product_id280 16505281 282Show flash count:283 284.. code-block:: bash285 286 root:/sys/kernel/debug/iio/iio:device0> cat flash_count287 150288 289Show firmware revision:290 291.. code-block:: bash292 293 root:/sys/kernel/debug/iio/iio:device0> cat firmware_revision294 1.6295 296Show firmware date:297 298.. code-block:: bash299 300 root:/sys/kernel/debug/iio/iio:device0> cat firmware_date301 06-27-2019302 3033. Device buffers304=================305 306This driver supports IIO buffers.307 308All devices support retrieving the raw acceleration, gyroscope and temperature309measurements using buffers.310 311The following device families also support retrieving the delta velocity, delta312angle and temperature measurements using buffers:313 314- ADIS16477315- ADIS16500316- ADIS16505317- ADIS16507318 319However, when retrieving acceleration or gyroscope data using buffers, delta320readings will not be available and vice versa.321 322Usage examples323--------------324 325Set device trigger in current_trigger, if not already set:326 327.. code-block:: bash328 329 root:/sys/bus/iio/devices/iio:device0> cat trigger/current_trigger330 331 root:/sys/bus/iio/devices/iio:device0> echo adis16505-2-dev0 > trigger/current_trigger332 root:/sys/bus/iio/devices/iio:device0> cat trigger/current_trigger333 adis16505-2-dev0334 335Select channels for buffer read:336 337.. code-block:: bash338 339 root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_x_en340 root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_y_en341 root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_z_en342 root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_temp0_en343 344Set the number of samples to be stored in the buffer:345 346.. code-block:: bash347 348 root:/sys/bus/iio/devices/iio:device0> echo 10 > buffer/length349 350Enable buffer readings:351 352.. code-block:: bash353 354 root:/sys/bus/iio/devices/iio:device0> echo 1 > buffer/enable355 356Obtain buffered data:357 358.. code-block:: bash359 360 root:/sys/bus/iio/devices/iio:device0> hexdump -C /dev/iio\:device0361 ...362 00001680 01 1f 00 00 ff ff fe ef 00 00 47 bf 00 03 35 55 |..........G...5U|363 00001690 01 1f 00 00 ff ff ff d9 00 00 46 f1 00 03 35 35 |..........F...55|364 000016a0 01 1f 00 00 ff ff fe fc 00 00 46 cb 00 03 35 7b |..........F...5{|365 000016b0 01 1f 00 00 ff ff fe 41 00 00 47 0d 00 03 35 8b |.......A..G...5.|366 000016c0 01 1f 00 00 ff ff fe 37 00 00 46 b4 00 03 35 90 |.......7..F...5.|367 000016d0 01 1d 00 00 ff ff fe 5a 00 00 45 d7 00 03 36 08 |.......Z..E...6.|368 000016e0 01 1b 00 00 ff ff fe fb 00 00 45 e7 00 03 36 60 |..........E...6`|369 000016f0 01 1a 00 00 ff ff ff 17 00 00 46 bc 00 03 36 de |..........F...6.|370 00001700 01 1a 00 00 ff ff fe 59 00 00 46 d7 00 03 37 b8 |.......Y..F...7.|371 00001710 01 1a 00 00 ff ff fe ae 00 00 46 95 00 03 37 ba |..........F...7.|372 00001720 01 1a 00 00 ff ff fe c5 00 00 46 63 00 03 37 9f |..........Fc..7.|373 00001730 01 1a 00 00 ff ff fe 55 00 00 46 89 00 03 37 c1 |.......U..F...7.|374 00001740 01 1a 00 00 ff ff fe 31 00 00 46 aa 00 03 37 f7 |.......1..F...7.|375 ...376 377See ``Documentation/iio/iio_devbuf.rst`` for more information about how buffered378data is structured.379 3804. IIO Interfacing Tools381========================382 383See ``Documentation/iio/iio_tools.rst`` for the description of the available IIO384interfacing tools.385