GPIO expansion support

[aleclofabbro]

Does this module support GPIO expansions like MCP23017 and similar?

[tjanson]

No, but it should be fairly easy to add. pi-gpio is essentially a node wrapper for the gpio utility, which works with the MCP23017.

I'm not sure whether these pins can can be gpio exported; if yes, It's just a matter of adding the -x mcp23017:100:0:0 (e.g., here).

If not, it'd be a bit more complicated, as the /sys/devices/virtual/gpio read/writes (e.g.) would have to be replaced by execs calling e.g., gpio -x mcp23017:100:0:0 read 101.

Does that help?

Oh, as an alternative: wiring-pi for node supports this out of the box. It wraps the (entire, I think?) WiringPi C library as a native addon to node. Relevant function.

[aleclofabbro]

thanks,
i put my question just to test the water ..
i'm not developing yet, i'm waiting for my first PI to come :) !
but i looked at the code, and i thought that it would have been enough to change the pinMapping properly...
i'll look to that alt module as well!
Thank you!