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Input expander booster pack?

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My Google-fu has let me down. Or perhaps there isn't such a thing. I was hoping to find a booster back to increase the # of I/O lines on the EXP430FR5994 Launchpad. I'm going to attempt to connect 2 5x8 switch matrix's most likely using SPI. But I'd rather not breadboard something up if there is already an addon to do what I need. 




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Looks interesting, but since I have no experience using a 430 or any micro controller I'm not sure if this would be something I could use. 

Here's a set of schematics I drew up rather quickly showing the Switch Matrix's and the interfaces of the existing boards. 

I think I will have to have separate Data lines, and I'm currently guessing the strobe lines will be in the form of address lines which would also need to be separate from everything else.  


Again forgive my ignorance. 

The markers indicate the pin and board number of the existing connection so I can keep everything straight for now. the I# are the switch inputs to what will be the 430 and the ST# are the Strobe lines which will come from the 430. 


Then the Cmos ttl will be run with Datalines, Interrupts, and Strobes. If I'm understanding all this.. 


I realize I bit off a large project to start with. But hey once piece at a time. First thing I need to figure out is how to input the switch matrix while leaving enough I/O to run the rest. I haven't drawn up the Plasma 7 segment displays as of yet. There are 4 6 Digit Alphanumeric displays, and 1 4 digit display. I think I should be able to run that with about 7 or 8 datalines, and a strobe. Not sure yet. 








5X8 MATRIX.bmp

Cabinet Switches.bmp

Lamp Interface.bmp

Solenoid Driver.bmp

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Apparently I'm making this way harder than I needed :) 

After looking at the original schematics for the two Switch Matrix's they share the same Data lines, and the second shared two of the address lines. So I got it stuck in my head that I would have to do the same when making the new design, and I don't. There is just enough I/O on MCP23S17 to handle the complete matrix and leave an I/O pin that I can use for the Test Switch. 


I've attached an updated Schematic showing the connections to the MCP23S17 Is this something that could work? 






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