Arduino I/O Expander with MCP23017 and 74HC4051 and Labview

[Nathan_B.]

You are using the wrong baud rate for the Uno.  The Uno uses 115200 for a baud rate.  However, you can also simply delete the inputs for the baud rate and board type and they will default to Uno settings.

[geotech_bd]

Many thanks! Works smoothly both on Uno and Mega.

[geotech_bd]

I have realized that this VI works only with bank-A in "write" and bank-B in "read" mode. No other arrangement is currenly working.

[geotech_bd]

After working with it for a while more, I ended up making sub-vi which can be used to put the MCP23017 in read or write mode (bank A and B in same mode). Now, I can atleast use the IC as a 16 bit input or output from labview thru arduino. I am working on a demo program. I'll upload everything later.