| .. include:: <isonum.txt> | |
| ============ | |
| Introduction | |
| ============ | |
| The main purpose of the Industrial I/O subsystem (IIO) is to provide support | |
| for devices that in some sense perform either | |
| analog-to-digital conversion (ADC) or digital-to-analog conversion (DAC) | |
| or both. The aim is to fill the gap between the somewhat similar hwmon and | |
| :doc:`input <../input>` subsystems. Hwmon is directed at low sample rate | |
| sensors used to monitor and control the system itself, like fan speed control | |
| or temperature measurement. :doc:`Input <../input>` is, as its name suggests, | |
| focused on human interaction input devices (keyboard, mouse, touchscreen). | |
| In some cases there is considerable overlap between these and IIO. | |
| Devices that fall into this category include: | |
| * analog to digital converters (ADCs) | |
| * accelerometers | |
| * capacitance to digital converters (CDCs) | |
| * digital to analog converters (DACs) | |
| * gyroscopes | |
| * inertial measurement units (IMUs) | |
| * color and light sensors | |
| * magnetometers | |
| * pressure sensors | |
| * proximity sensors | |
| * temperature sensors | |
| Usually these sensors are connected via :doc:`SPI <../spi>` or | |
| :doc:`I2C <../i2c>`. A common use case of the sensors devices is to have | |
| combined functionality (e.g. light plus proximity sensor). |