rces, you have to
   configure the PCA9555 itself.  This requires two steps.  First,
   you have to configure the "I2C bus" that the chip is connected to,
   via the <a href="JSONConfigRef.htm#i2c0"><tt>i2c0</tt></a> or
   <a href="JSONConfigRef.htm#i2c1"><tt>i2c1</tt></a> property, depending
   on which GPIO pins the chip is connected to.
</p>
<pre>
   {
      i2c0: {
         sda: 13,
         scl: 14,
      },
   }
</pre>
<p>
   Note that an I2C bus can be shared among several chips - not just multiple
 