89c2051 taking >2v as logic 1

[ccatty]

hi friends,
im doin a line follower bot.
i hav 2 doubts.
my comparator output voltage when sensors blocked and unblocked are 3.7v and 2v.

these two are given as inputs to my 89c2051 controller.

the problem here is controller taking both 3.7v and 2v as logic1..

how to reduce the output voltage of comparator from 2v to 0?

or

how to make controller to take 2v as logic 0?

hope u l do clarify my doubt..

thnks

 

[colin mac]

Use a reference of some voltage greater than 2V at P1.1. When the input to P1.0 is lower than Vref, the output of the comparator is set 0.

 

[ccatty]

thnks a lot

 

[ccatty]

hi ive tried as u said, but still opamp output voltges r 3.7v and 2v..
for logic0, opamp shd give output as 0. but its givin 2v....wats d reason for this?