Documentation - libffi5 requirements

[hukuzatuna]

You may wish to include a note in README.md to the effect that on a Raspberry Pi (running Rasbian Jessie) the following packages need to be installed: libffi5, libffi5-dbg, and libffi5-dev.

[mame-erl]

Yes, came across this as well.

[DonBower]

I only had to install ibffi-dev.
Wonder if I sould redo setup with the three packages you mentioned above>

[kyletaylored]

If you use the new PyPi version, this is fixed by using the new smbus2 package which is built in Python, and doesn't require other system packages like these mentioned.

See my fork at kyletaylored/python-tsl2591