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1.. SPDX-License-Identifier: GPL-2.02 3===============4ADXL380 driver5===============6 7This driver supports Analog Device's ADXL380/382 on SPI/I2C bus.8 91. Supported devices10====================11 12* `ADXL380 <https://www.analog.com/ADXL380>`_13* `ADXL382 <https://www.analog.com/ADXL382>`_14 15The ADXL380/ADXL382 is a low noise density, low power, 3-axis accelerometer with16selectable measurement ranges. The ADXL380 supports the ±4 g, ±8 g, and ±16 g17ranges, and the ADXL382 supports ±15 g, ±30 g, and ±60 g ranges.18 192. Device attributes20====================21 22Accelerometer measurements are always provided.23 24Temperature data are also provided. This data can be used to monitor the25internal system temperature or to improve the temperature stability of the26device via calibration.27 28Each IIO device, has a device folder under ``/sys/bus/iio/devices/iio:deviceX``,29where X is the IIO index of the device. Under these folders reside a set of30device files, depending on the characteristics and features of the hardware31device in questions. These files are consistently generalized and documented in32the IIO ABI documentation.33 34The following tables show the adxl380 related device files, found in the35specific device folder path ``/sys/bus/iio/devices/iio:deviceX``.36 37+---------------------------------------------------+----------------------------------------------------------+38| 3-Axis Accelerometer related device files | Description |39+---------------------------------------------------+----------------------------------------------------------+40| in_accel_scale | Scale for the accelerometer channels. |41+---------------------------------------------------+----------------------------------------------------------+42| in_accel_filter_high_pass_3db_frequency | Low pass filter bandwidth. |43+---------------------------------------------------+----------------------------------------------------------+44| in_accel_filter_high_pass_3db_frequency_available | Available low pass filter bandwidth configurations. |45+---------------------------------------------------+----------------------------------------------------------+46| in_accel_filter_low_pass_3db_frequency | High pass filter bandwidth. |47+---------------------------------------------------+----------------------------------------------------------+48| in_accel_filter_low_pass_3db_frequency_available | Available high pass filter bandwidth configurations. |49+---------------------------------------------------+----------------------------------------------------------+50| in_accel_x_calibbias | Calibration offset for the X-axis accelerometer channel. |51+---------------------------------------------------+----------------------------------------------------------+52| in_accel_x_raw | Raw X-axis accelerometer channel value. |53+---------------------------------------------------+----------------------------------------------------------+54| in_accel_y_calibbias | y-axis acceleration offset correction |55+---------------------------------------------------+----------------------------------------------------------+56| in_accel_y_raw | Raw Y-axis accelerometer channel value. |57+---------------------------------------------------+----------------------------------------------------------+58| in_accel_z_calibbias | Calibration offset for the Z-axis accelerometer channel. |59+---------------------------------------------------+----------------------------------------------------------+60| in_accel_z_raw | Raw Z-axis accelerometer channel value. |61+---------------------------------------------------+----------------------------------------------------------+62 63+----------------------------------+--------------------------------------------+64| Temperature sensor related files | Description |65+----------------------------------+--------------------------------------------+66| in_temp_raw | Raw temperature channel value. |67+----------------------------------+--------------------------------------------+68| in_temp_offset | Offset for the temperature sensor channel. |69+----------------------------------+--------------------------------------------+70| in_temp_scale | Scale for the temperature sensor channel. |71+----------------------------------+--------------------------------------------+72 73+------------------------------+----------------------------------------------+74| Miscellaneous device files | Description |75+------------------------------+----------------------------------------------+76| name | Name of the IIO device. |77+------------------------------+----------------------------------------------+78| sampling_frequency | Currently selected sample rate. |79+------------------------------+----------------------------------------------+80| sampling_frequency_available | Available sampling frequency configurations. |81+------------------------------+----------------------------------------------+82 83Channels processed values84-------------------------85 86A channel value can be read from its _raw attribute. The value returned is the87raw value as reported by the devices. To get the processed value of the channel,88apply the following formula:89 90.. code-block:: bash91 92 processed value = (_raw + _offset) * _scale93 94Where _offset and _scale are device attributes. If no _offset attribute is95present, simply assume its value is 0.96 97The adis16475 driver offers data for 2 types of channels, the table below shows98the measurement units for the processed value, which are defined by the IIO99framework:100 101+-------------------------------------+---------------------------+102| Channel type | Measurement unit |103+-------------------------------------+---------------------------+104| Acceleration on X, Y, and Z axis | Meters per Second squared |105+-------------------------------------+---------------------------+106| Temperature | Millidegrees Celsius |107+-------------------------------------+---------------------------+108 109Usage examples110--------------111 112Show device name:113 114.. code-block:: bash115 116 root:/sys/bus/iio/devices/iio:device0> cat name117 adxl382118 119Show accelerometer channels value:120 121.. code-block:: bash122 123 root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_raw124 -1771125 root:/sys/bus/iio/devices/iio:device0> cat in_accel_y_raw126 282127 root:/sys/bus/iio/devices/iio:device0> cat in_accel_z_raw128 -1523129 root:/sys/bus/iio/devices/iio:device0> cat in_accel_scale130 0.004903325131 132- X-axis acceleration = in_accel_x_raw * in_accel_scale = −8.683788575 m/s^2133- Y-axis acceleration = in_accel_y_raw * in_accel_scale = 1.38273765 m/s^2134- Z-axis acceleration = in_accel_z_raw * in_accel_scale = -7.467763975 m/s^2135 136Set calibration offset for accelerometer channels:137 138.. code-block:: bash139 140 root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_calibbias141 0142 143 root:/sys/bus/iio/devices/iio:device0> echo 50 > in_accel_x_calibbias144 root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_calibbias145 50146 147Set sampling frequency:148 149.. code-block:: bash150 151 root:/sys/bus/iio/devices/iio:device0> cat sampling_frequency152 16000153 root:/sys/bus/iio/devices/iio:device0> cat sampling_frequency_available154 16000 32000 64000155 156 root:/sys/bus/iio/devices/iio:device0> echo 32000 > sampling_frequency157 root:/sys/bus/iio/devices/iio:device0> cat sampling_frequency158 32000159 160Set low pass filter bandwidth for accelerometer channels:161 162.. code-block:: bash163 164 root:/sys/bus/iio/devices/iio:device0> cat in_accel_filter_low_pass_3db_frequency165 32000166 root:/sys/bus/iio/devices/iio:device0> cat in_accel_filter_low_pass_3db_frequency_available167 32000 8000 4000 2000168 169 root:/sys/bus/iio/devices/iio:device0> echo 2000 > in_accel_filter_low_pass_3db_frequency170 root:/sys/bus/iio/devices/iio:device0> cat in_accel_filter_low_pass_3db_frequency171 2000172 1733. Device buffers174=================175 176This driver supports IIO buffers.177 178All devices support retrieving the raw acceleration and temperature measurements179using buffers.180 181Usage examples182--------------183 184Select channels for buffer read:185 186.. code-block:: bash187 188 root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_accel_x_en189 root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_accel_y_en190 root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_accel_z_en191 root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_temp_en192 193Set the number of samples to be stored in the buffer:194 195.. code-block:: bash196 197 root:/sys/bus/iio/devices/iio:device0> echo 10 > buffer/length198 199Enable buffer readings:200 201.. code-block:: bash202 203 root:/sys/bus/iio/devices/iio:device0> echo 1 > buffer/enable204 205Obtain buffered data:206 207.. code-block:: bash208 209 root:/sys/bus/iio/devices/iio:device0> hexdump -C /dev/iio\:device0210 ...211 002bc300 f7 e7 00 a8 fb c5 24 80 f7 e7 01 04 fb d6 24 80 |......$.......$.|212 002bc310 f7 f9 00 ab fb dc 24 80 f7 c3 00 b8 fb e2 24 80 |......$.......$.|213 002bc320 f7 fb 00 bb fb d1 24 80 f7 b1 00 5f fb d1 24 80 |......$...._..$.|214 002bc330 f7 c4 00 c6 fb a6 24 80 f7 a6 00 68 fb f1 24 80 |......$....h..$.|215 002bc340 f7 b8 00 a3 fb e7 24 80 f7 9a 00 b1 fb af 24 80 |......$.......$.|216 002bc350 f7 b1 00 67 fb ee 24 80 f7 96 00 be fb 92 24 80 |...g..$.......$.|217 002bc360 f7 ab 00 7a fc 1b 24 80 f7 b6 00 ae fb 76 24 80 |...z..$......v$.|218 002bc370 f7 ce 00 a3 fc 02 24 80 f7 c0 00 be fb 8b 24 80 |......$.......$.|219 002bc380 f7 c3 00 93 fb d0 24 80 f7 ce 00 d8 fb c8 24 80 |......$.......$.|220 002bc390 f7 bd 00 c0 fb 82 24 80 f8 00 00 e8 fb db 24 80 |......$.......$.|221 002bc3a0 f7 d8 00 d3 fb b4 24 80 f8 0b 00 e5 fb c3 24 80 |......$.......$.|222 002bc3b0 f7 eb 00 c8 fb 92 24 80 f7 e7 00 ea fb cb 24 80 |......$.......$.|223 002bc3c0 f7 fd 00 cb fb 94 24 80 f7 e3 00 f2 fb b8 24 80 |......$.......$.|224 ...225 226See ``Documentation/iio/iio_devbuf.rst`` for more information about how buffered227data is structured.228 2294. IIO Interfacing Tools230========================231 232See ``Documentation/iio/iio_tools.rst`` for the description of the available IIO233interfacing tools.234