[Help] build IR Sensor in digital output form.

[scdvom]

Hi, can anyone show me the layout circuit to build the IR Sensor which output in digital form.

eg.
within the range (5cm).show 1.
out of range.show 0.

thanks for helping.

 

[deepuj]

The simplest solution will be to put an IR LED with a proper beam (you might need to cover the sides so that no direct beam falls in the sensor) and an IR sensor. use an op-amp to compare the sensor output to a reference voltage and give out a high voltage (logic 1; for opamp it should be the high saturation value) when is within a set level and fall to 0 when it is below the level. You can change the ref. level to get an accurate measurement.

Refer to this for more info: http://www.ecircuitcenter.com/Circuits/op_comp/op_comp.htm

also http://en.wikipedia.org/wiki/Comparator

Try to use an op amp with a single rail power supply (to avoid hazzles of a two rail one!).

Regarding the IR LED and sensor, try using a modulating frequency on the IR LED and a corresponding filter at the receiver to avoid noise pick up. Choose the frequency so that it is out of any IR remotes or natural IR sources range.

 

[varunme]

How can we build an ir sensor in digital form without an opamp ?

---------- Post added at 02:27 ---------- Previous post was at 02:21 ----------

just by using the switch voltage of the transistor ?

---------- Post added at 02:27 ---------- Previous post was at 02:27 ----------

just by using the switch voltage of the transistor ?