detect increasing or decreasing pot output

I want to detect whether potentiometer output voltage is increasing or decreasing and convert this to a digital signal.
the circuit must be able to sense tiny voltage changes (order of 10mV) and with high speed.
all im interested is if Vout increases or decreases not by how much
increasing V =high output
decreasing or stable V =low output
how can i achieve this?

Use the 1.1 volt bandgap reference

Two options, simple and fast or mathematically correct.

Simple : take two or three values compare them to eachother and see if they are decreasing or increasing
Math : Calculate inclination of a line... Google away, lots of nice little tutorials...

A standard data slicer does this - see enclosed.

Adjust r/c for the time constant you need.

It works up to MHz with a fast comparator....

To get a low for falling /static signal apply a small +ve bias to the - input of the comparator...

eg a 1Mohm to +1v

regards

Allan

slicer.pdf (13.6 KB)

AWOL:
Use the 1.1 volt bandgap reference

i dont want use a microcontroller

allanhurst:
To get a low for falling /static signal apply a small +ve bias to the - input of the comparator...

eg a 1Mohm to +1v

why is the bias needed?
and can you provide a typical circuit of time constant 10ms.offset voltage 10mV using lm339 comparator

SumitAich:
i dont want use a microcontroller

So why are you posting in the "Project Guidance" section of a microcontroller forum?

allanhurst:
A standard data slicer does this - see enclosed.

Adjust r/c for the time constant you need.

It works up to MHz with a fast comparator....

To get a low for falling /static signal apply a small +ve bias to the - input of the comparator...

eg a 1Mohm to +1v

regards

Allan

will this work?

I want to detect whether an analog signal is increasing or decreasing and convert this to a digital signal.
the circuit must be able to sense tiny voltage changes (order of 10mV) and with high speed.
all im interested is if Vout increases or decreases not by how much
increasing V =high output
decreasing or stable V =low output
how can i achieve this?
Below is the LTspice simulation of my take on a circuit.
It uses an opamp differentiator circuit to convert the slope change into about a 1V step signal to minimize offset effects. This goes to an opamp comparator circuit to give the desired positive pulse output for a positive slope on the input, and zero volts otherwise
how do i eliminate noise amplification?

You will have to condition your input voltage to get it into the allowed 0V to 5V range. Connect the conditioned signal to an analog input pin. Read the analog input pin. If the number has gone up the analog voltage has increased by about 5 mV or more. If the number has gone down the voltage has decreased by about 5 mV or more.

OP did not want to use an Arduino for that.
Leo..