sensor-streams.rst

Sensor Streams

Sensor drivers can make their data available to core 1 in a stream-like format. This allows batch-reading many samples and shoud reduce pressure on the Epicardium API this way. Sensor streams are read on core 1 using :c:func:`epic_stream_read`.

This page intends to document how to add this stream interface to a sensor driver. It also serves as a reference of existing streams. For that, take a look at the definitions in the :c:type:`stream_descriptor` enum.

Adding a new Stream

The list of possible sensor streams must be known at compile time. Each stream gets a unique ID in the :c:type:`stream_descriptor` enum. Please do not assign IDs manually but instead let the enum assign sequencial IDs. :c:macro:`SD_MAX` must always be the highest stream ID. Additionally, please document what this stream is for using a doc-comment so it shows up on this page.

When a sensor driver enables data collection, it should also register its respective stream. This is done using a :c:type:`stream_info` object. Pass this object to :c:func:`stream_register` to make your stream available. Your driver must guarantee the :c:member:`stream_info.queue` handle to be valid until deregistration using :c:func:`stream_deregister`.

Definitions