Advice on measuring signal strength

Projects General Guidance
1

Hi all!

I've been searching around but without success.
My goal is to measure the signal strength of a tyical 38 khz ir receiver.
I thought that the analogRead function should give me the output voltage and this could give me an idea of how intense the signal is being received.
I have done a simple sketch for reading this input but i think things work different that i expected.

The thing is that sensor is always showing a 5v value 1023 and dropping to 1 to 5 value but i am not sure that is consequence of my ir ir signal coming to the sensor, as if i don't push any button the behaviour is similar.

attached you can find some results from the serial output with a 220 ohm resistor into the output sensor but maybe is completely useless.

Thanks in advance.

analog read 220 ohm (1.69 KB)

2

My goal is to measure the signal strength of a tyical 38 khz ir receiver.

There is no way you can do that because the signal is amplified and processed before coming out of the receiver chip.

The thing is that sensor is always showing a 5v value 1023 and dropping to 1 to 5 value

Yes it always will irrespective of the received signal intensity.

3

This should help explain why you are seeing +5 Volts constantly:

https://learn.sparkfun.com/tutorials/ir-communication/all

4

Thank or the answers.

So there is no way to use them as a kind of proximity sensors.
I wil have to go on a proximity ir sensors. wich are different i guess.
I will go to check this point. Advices are welcome about wich are the cheaper and best proximity sensors to use for a orientation project with two step motors tracking a point. wich i would like to be a ir remote controller.

5

There are lots of IR sensors, one common one is:

Note that some come in short-range and some in long-range and one model in fixed-range. You can also Search on eBay.

Ray

6

Here is an IR receiver that works as a proximity sensor:

TSSP58P38 or TSSP4P38 (The first one is more directional)

The proximity is indicated by the length (time) of the output pulse.

(See data sheet)

However, normal TV type IR receivers provide an inverted digital output. (HIGH or LOW)

7

Nice
those last ones are more approx as what i am searching.
In the end what i am searching is a sensor that would track or be stimulated form a some kind of point and let me know different distance in order to be capable of orienting the destination point to center the source.

Thank you.

8

You are looking for far far more than you know.
That is a very difficult task and not something you can get from a simple sensor.

You can do it with two video cameras and measuring the stereoscopic displacement.
The other thing is to use an IR distance camera like the kinect.
Both solutions do not involve an arduino.