debugging.md

+# Debugging
+
+## Contents
+
+1. [File Sink and Source](#file-sink-and-source)
+
+## File Sink and Source
+
+GNU Radio flowgraphs are real-time signal processing applications that typically
+operate on continuous streams of data. This can make it difficult to investigate
+signal characteristics or debug unexpected behaviour. The GNU Radio *File Sink*
+and *File Source* blocks are a handy way to allow offline investigation of the
+signal at various points in your flowgraph using Python scientific libraries or
+MATLAB.
+
+<div align="center">
+
+![File Sink](images/file_sink.png)
+![File Source](images/file_source.png)
+
+</div>
+
+When included in your flowgraph, the *File Sink* block will save data samples
+to a binary file that can then be loaded as an array in Python or MATLAB.
+Similarly, a known test waveform can be generated in Python or MATLAB and then
+fed into your flowgraph using the *File Source* block. The combination of sink
+and source can also be used to save a waveform for latter playback.
+
+See the following GNU Radio documentation pages to understand these blocks and
+how to binary waveforms files can be loaded/created in MATLAB and Python.
+
+- [GNU Radio File Sink](https://wiki.gnuradio.org/index.php/File_Sink)
+- [GNU Radio File Source](https://wiki.gnuradio.org/index.php/File_Source)