Increasing IO with SPI using the Au and Br

[MichaelTuckwell]

I'm currently developing an application with the Au and Br using Alchitry Labs v1.1.6 in
Lucid, however I need many more switching outputs, so serial I/O expansion is needed.

The switching speed requirement is very high so SPI is my prefered choice and the
MCP23S17 16-Bit SPI Expander with serial interface is ideal for the application for 
extending multiple GPIOs. 

I'm asking for SPI implementation tips for the Au and Br as the current tutorial is
written for the Mojo, and I'm not sure how to use the spi_master compontent in
Alchitry Labs, or to add the SPI I/O to a constraints file. 

Also is there a Br constraints file for the Au?

Thanks in advance,

Mick

[MichaelTuckwell]

Based on the following link;

https://github.com/alchitry/Alchitry-Lab...erter.java

I have created a new constraint file called, au_br.acf wth the following two lines;

pin spi_ss SPI_SS;
pin spi_sck SPI_SCK;

and declared them as input and output respectively in the au_top.luc file

input spi_ss,
output spi_sck,

So far only the spi_ss can be used as the project will not build with spi_sck.