5V ---> ~3.3V
Baud = ~9600
Tested this using an NTE123A NPN BJT, and a 3.6V Zener with a simple Arduino sketch. The Arduino sketch set a digital pin high and low with a span of 2 sec between transitions.
Vin(high) ~= 4.65V, Vin(low) ~= 0V
Vout(high) ~= 3.02V, Vout(low) ~= 0.08V
Will test this with a faster signal as soon as an oscilloscope is handy. Then a communication with another device...
