set pin on mcp23017 using raspberry pi shell

C++

# for original rev1 Pi
sudo i2cset -y 0 0x20 0x00 0xff
sudo i2cset -y 0 0x20 0x14 0x01
#           address register value 
# for rev2 Pi or later
sudo i2cset -y 1 0x20 0x00 0xff
sudo i2cset -y 1 0x20 0x14 0x01
#           address register value

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