2xNOT analog-to-digital

Converts analog signal to digital 1/0.  Has  hysteresis in switch. Change #R2 to control hysteresis window. For example: #R1=50kOm  #R2=60kOm - bigger hysteresis. #R1=50kOm #R2=600kOm - smaller hysteresis. #R2 should be > #R1 or else it won't work.