View source for SBCX-TN-001: Android Things and SPI bus

==Introduction==
When using Android for embedded platforms, software developers have to face several challenges. Most of them are due to the fact that Android was designed originally to run on mobile devices which meet specific hardware requirements. As such, the APIs to access the hardware interfaces from the application layer are defined accordingly.

These interfaces don't include the ones that are typically used in products addressing industrial applications: I2C bus, SPI bus, UARTs, etc. However, as Android popularity is growing outside the mobile world too, Google defined a set of additional APIs to standardize the access to these interfaces as well. These new APIs are part of the [https://developer.android.com/things/index.html Android Things project].

This Technical Note describes the implementation of the [https://developer.android.com/things/sdk/pio/spi.html APIs related to the SPI bus] to access the bus SPI4 of the SBCX platform in the form of a native library. The solution was tested with Android 4.4.3.