up.
</p>
<p>
   Once you've physically wired the SDA and SCL GPIO pins to the chips,
   there's one more step: you have to tell the Pinscape software about the
   bus setup.  You do this with the  <a href="JSONConfigRef.htm#i2c0"><tt>i2c0</tt></a>
   and <a href="JSONConfigRef.htm#i2c1"><tt>i2c1</tt></a> properties.
   If you selected an SDA/SCL pair designated I2C0, use the <tt>i2c0</tt>
   property; if the SDA/SCL pair is on I2C1, use <tt>i2c1</tt>.
</p>
<pre>
   {
      i2c0: {
         sda: 12,   // SDA