Update introduction.md

docs/build/man/introduction.md

-
 <a id='Introduction-1'></a>
 
 # Introduction
@@ -8,3 +7,24 @@
 
 ## Installation
 
+## Future Work
+
+### SPI Development
+The SPI development is done in C and in a forked repository, currently
+separated from the julia project. If you wish to work on the SPI implementation,
+simply clone the repository "serbus", a small C stack available at
+`github.com/mgreiff/serbus` into your julia package directory (for example
+`~/.julia/v0.6`). Then, in the LabConnections package on the host computer, run
+`flash_BB.sh` in the `/utils` directory transferring both LabConnections and
+serbus to the BB.
+
+On the BB, run
+
+    cp /home/debian/juliapackages/serbus/bb_spi.sh /home/debian
+
+and then execute
+
+    ./bb_spi.sh
+
+in the `/home/debian` directory to run the SPI example with the ADC from SPI0.
+