Hello everyone,
I am trying to build a robot that will drive auotumatically from one place to another.
As part of the requirment of the project the robot have to drive a way of 5 meters from the sorce to destination using IR transmitter and a tsop Receiver . My circuit works until 2.5 meters and im trying to find a way how to increase the destination to 5m.
Thanks in advance.

 

So without a schematic and a description of how you are using those components, how do you expect us to respond?

 

How can I collimate the radiation?
I built this circuit:

At the left side of the R1 resistor, I have an Arduino Nano controller that is creating a modulated pulse.
The frequency that is modulated is 38Khz and the modulation frequency is 100Hz.
My duty cycle is about 65%.
Now I have the ability to receive 4.5 meters but it is very rickety and every movement to the left or to the right makes it impossible to receive the signal.
How can I improve the distance and the stability of my system?
Thank you very much.

 

The frequency that is modulated is 38Khz and the modulation frequency is 100Hz

How are you modulating a 38kHz modulated signal at 100Hz and 65% duty cycle? Could you draw out the waveform you described?

 

A simple thing to try is to add more LEDs.
Just add a two LED, one resistor string in parallel with the ones you have between +5V and the transistor.
You may have to also reduce the value of R1 to get sufficient base current to saturate the transistor.

 

Are you aware that the TSOP receiver does not like a continuous signal? They have strict limits for the length of the 38 KHz busts and their separation. I have used these , and when properly modulated, you can point the transmitter in any direction and the receiver will puck it up via reflections. 5 m in a direct line should be easily achievable.

Bob

 

Change R1 to 220 ohms

Add two more LEDs and a resistor in parallel with your existing two LEDs and resistor to double the light.

 

Are you aware that the TSOP receiver does not like a continuous signal? They have strict limits for the length of the 38 KHz busts and their separation. I have used these , and when properly modulated, you can point the transmitter in any direction and the receiver will puck it up via reflections. 5 m in a direct line should be easily achievable.

Bob

Some newer versions have been redesigned to handle the continuous signal. I think his comment about 100Hz addresses your concern but I am waiting for his clarification.

 

The requirement for my project is to do it in two ways. One of them is with 100HZ and 200HZ.
I'm adding the picture of the 38Khz frequency from the scope and the 200 Hz modulation.

 

Add two more LEDs and a resistor in parallel with your existing two LEDs and resistor to double the light.

Deja Vu all over again.

 

Some newer versions have been redesigned to handle the continuous signal. I think his comment about 100Hz addresses your concern but I am waiting for his clarification.

This is how it looks like my modulation. Sorry for drawing it this way(This is my only option right now).

 

Deja Vu all over again.

If I'd clean up after myself, my wife wouldn't have interrupted my writing and I would have looked like the smart one!

 

Deja Vu all over again.

Which value of the resistor?
I had 3 when I built my circuit for the first time but I saw that the distance is smaller this way. I guess that the lower current makes the difference.

 

Which value of the resistor?
I had 3 when I built my circuit for the first time but I saw that the distance is smaller this way. I guess that the lower current makes the difference.

Because R1 at the base was too small to handle the larger collector current.

Use 470 as R1 if you have one pair of LEDs, 220 if you have two pairs and 100ohms if you have four pairs of LEDs

 

Which value of the resistor?
I had 3 when I built my circuit for the first time but I saw that the distance is smaller this way. I guess that the lower current makes the difference.

You say project

Is this "school work" ?

 

Are you aware that the TSOP receiver does not like a continuous signal? They have strict limits for the length of the 38 KHz busts and their separation. I have used these , and when properly modulated, you can point the transmitter in any direction and the receiver will puck it up via reflections. 5 m in a direct line should be easily achievable.

Bob

My goal is to make an autonomic car that will be able to drive from the source to destination so I must that only one of the receivers will detect the signal.
Yesterday I tried to do something new. I changed my program and I put 3 receivers (Front, Right, and left). I saw that when I decreased the duty cycle to about 40% I saw that all 3 receivers detect the pulse and this is not what I want in my project.
So I am trying to find a solution with my previous circuit and software that I uploaded here.

 

You say project

Is this "school work" ?

Yes

 

Have you identified the problem? Why are you having trouble with selectivity?

 

Have you identified the problem? Why are you having trouble with selectivity?

I didn't recognize what is the cause of this problem.

 

I didn't recognize what is the cause of this problem.

Well, try this, why would it work? What about it makes you think it would do something different than it did?