* voltages corresponding to 3/4 of full scale (192 or 0xc0)
* NOTE: The -12V input needs an additional factor to account
* for the Vref pullup resistor.
* voltages corresponding to 3/4 of full scale (192 or 0xc0)
* NOTE: The -12V input needs an additional factor to account
* for the Vref pullup resistor.