Sun Nov 4 00:06:45 EDT 2012

Cleaning up digital out

This needs an inverter that's run from a clean power supply.
Additionally, running this at about 1.0-1.2V would give a good V-range
for an exp converter, as it has midrange around 0.5-0.6V which could
drive a bipolar base directly.

- a clean voltage supply
- inverter running of of 1V

maybe just 2 diodes (transisto diodes?) connected to V+ through a
current-limiting resistor.  this would set the "mid level" current.

maybe there's a way to set the 0 an 1 levels this way also?  have 2
diodes, one with minimal current, one with maximal current, then gate
this to transistor bases.  to keep the currents low, 2 diodes could be
used on the high end.

it seems a differential pair is a better fit for this.  this then has
a 0V level and a diode-controlled 1 level.  what about the uC shorting
a diode stack?  difference between 1 and 2 diodes?